After lots of data collection, historical weather checking, and polling, Saturday, APRIL 9th is the date for the next Sphere Stuff Day and Okanagan Valley-wide Radio Amateur swap meet. This gives those in Washington & Oregon time to recover from Puyallup, and should be good weather for both travel and display for everybody. This will be at Sphere Research, in West Kelowna, BC, about 4 hours from Vancouver. See our website for all the contact details and exact address. Starts 9am, but set up for those to display starts at 7am, and we can accommodate 2 Rvs and some limited overnight guests. We will have tons of test equipment, (Tek, HP, Boonton, Fluke, Trak, PMI/Wavetek and much more) spare parts, plug-in modules, manuals and salvage units. Also tons of free electronic goodies of all kinds, as well as dirt cheap items, PLUS a wide range of ham gear and related items from ICOM to Collins for selling, swapping and testing. There is a lot of very cool stuff we are clearing out to make space, so whether you want RF parts, transmitting tubes, test gear, CRTs, nicads, scopes, meters, parts or what-have-you, you WILL find it here. There will also be solar panels, tons of high quality panel meters, Tek 11K items, lots of time code systems and displays (for that home launch pad you've been working on), and a huge assortment of crystals, mechanical filters, microwave filters and precision oscillator modules. Susan will also provide Visa/MC and Paypal services for payments if needed. Want space to show and sell your gear, just CONTACT WALTER to reserve a spot, strictly first come, first served. Trunk/truck sales are fine, or you can set up a table, as you wish. We can provide power for some locations, and we will have some interesting test gear to allow you to demo and verify your stuff. YES, we take requests for specific items you may be interested in, and YES we will post a list in advance of some key items and prices for those that just can't get up here, but shipping costs can be annoying for big items, which is exactly why we suggest showing up in person. Those that have been here in the past have had a great time, so we invite you to drop by and snorkel through the goodies to your heart's content. Plus, who knows what fabulous treasures others will bring to trade? We may also be able to set up a BBQ spot for snacks, and we will have off-air frequency checks, RF power testing, and a master frequency reference to let you check your counters and other gear. Plus, lots of help and advice from a great cross-section of people you don't get to see so often. All in all, it should be a great time. RSVP if you need exhibit space, or just to say hi, and remember that we do take requests to set out just the items you need (we have 4 storage buildings, we can't set it ALL out). If you have been missing a good surplus store experience for a while, come by and get that taken care of here! Remember, Saturday, April 9th. I will post again as we get closer to remind you of the date. all the best, walter & susan sphere research corp. http://www.sphere.bc.ca/test -- Walter Shawlee 2, President Sphere Research Corporation 3394 Sunnyside Rd., West Kelowna, BC V1Z 2V4 CANADA Phone: (250) 769-1834 walter2@sphere.bc.ca WS2: We're all in one boat, no matter how it looks to you. Love is all you need. (John Lennon) But, that doesn't mean other things don't come in handy. (WS2)

Hi Ok, just to be absolutely certain: There is a iron clad 100% guarantee of perfect weather that weekend. (Yes, I’ve been in BC in the spring …:) Bob > On Feb 16, 2016, at 5:37 PM, walter shawlee 2 <walter2@sphere.bc.ca> wrote: > > After lots of data collection, historical weather checking, and polling, Saturday, APRIL 9th > is the date for the next Sphere Stuff Day and Okanagan Valley-wide Radio Amateur swap meet. This gives those in Washington & Oregon time to recover from Puyallup, and should be good weather for both travel and display for everybody. This will be at Sphere Research, in West Kelowna, BC, about 4 hours from Vancouver. See our website for all the contact details and exact address. Starts 9am, but set up for those to display starts at 7am, and we can accommodate 2 Rvs and some limited overnight guests. > > We will have tons of test equipment, (Tek, HP, Boonton, Fluke, Trak, PMI/Wavetek and much more) spare parts, plug-in modules, manuals and salvage units. Also tons of free electronic goodies of all kinds, as well as dirt cheap items, PLUS a wide range of ham gear and related items from ICOM to Collins for selling, swapping and testing. There is a lot of very cool stuff we are clearing out to make space, so whether you want RF parts, transmitting tubes, test gear, CRTs, nicads, scopes, meters, parts or what-have-you, you WILL find it here. There will also be solar panels, tons of high quality panel meters, Tek 11K items, lots of time code systems and displays (for that home launch pad you've been working on), and a huge assortment of crystals, mechanical filters, microwave filters and precision oscillator modules. Susan will also provide Visa/MC and Paypal services for payments if needed. > > Want space to show and sell your gear, just CONTACT WALTER to reserve a spot, strictly first come, first served. Trunk/truck sales are fine, or you can set up a table, as you wish. We can provide power for some locations, and we will have some interesting test gear to allow you to demo and verify your stuff. YES, we take requests for specific items you may be interested in, and YES we will post a list in advance of some key items and prices for those that just can't get up here, but shipping costs can be annoying for big items, which is exactly why we suggest showing up in person. Those that have been here in the past have had a great time, so we invite you to drop by and snorkel through the goodies to your heart's content. Plus, who knows what fabulous treasures others will bring to trade? > > We may also be able to set up a BBQ spot for snacks, and we will have off-air frequency checks, RF power testing, and a master frequency reference to let you check your counters and other gear. Plus, lots of help and advice from a great cross-section of people you don't get to see so often. > > All in all, it should be a great time. RSVP if you need exhibit space, or just to say hi, and remember that we do take requests to set out just the items you need (we have 4 storage buildings, we can't set it ALL out). If you have been missing a good surplus store experience for a while, come by and get that taken care of here! > > Remember, Saturday, April 9th. I will post again as we get closer to remind you of the date. > > all the best, > > walter & susan > sphere research corp. > http://www.sphere.bc.ca/test > > -- > Walter Shawlee 2, President > Sphere Research Corporation > 3394 Sunnyside Rd., West Kelowna, BC > V1Z 2V4 CANADA Phone: (250) 769-1834 > walter2@sphere.bc.ca > WS2: We're all in one boat, no matter how it looks to you. > Love is all you need. (John Lennon) > But, that doesn't mean other things don't come in handy. (WS2) > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it, it is clear that it is defective. 1. It never heats up. 2. The reference voltage is zero. 3. Only noise is seen on the output pin. I tested with a 12.54V, 2A supply voltage with around 30mV noise. That should be sufficient to test. All I was looking for was a 5Mhz signal whose frequency changed when the adjustment pin was either tied to ground or the reference voltage. Never got that far because I never go a signal at all. The seller packed it well and shipped it promptly. I will see how he handles it. Mike

Hi The 260’s that I have seen from inside the USA have been pretty good (not perfect, but certainly not dead). Most of the issues have been quibbles. Phase noise not quite in spec. ADEV not quite as good as it might have been. Everything I have seen so far from China (260 or not) has been very hit or miss. Stuff that is called “scrap for parts only” (like a pile of 10 Rb’s I have here) may turn up more working parts than something labeled “great / tested / buy now / first best great product (a direct quote)“. I have tried the “buy a few and then go back” approach. There has been little correlation between what I got the second time and what came in first. My conclusion (often stated) is that the salvage process over there is pretty brutal. Bob > On Feb 16, 2016, at 7:58 PM, timenut@metachaos.net wrote: > > I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it, > it is clear that it is defective. > > 1. It never heats up. > > 2. The reference voltage is zero. > > 3. Only noise is seen on the output pin. > > I tested with a 12.54V, 2A supply voltage with around 30mV noise. That should > be sufficient to test. > > All I was looking for was a 5Mhz signal whose frequency changed when the > adjustment pin was either tied to ground or the reference voltage. Never got > that far because I never go a signal at all. > > The seller packed it well and shipped it promptly. I will see how he handles > it. > > > Mike > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

1. It never heats up.
2. The reference voltage is zero.
3. Only noise is seen on the output pin.

On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: > I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it, > it is clear that it is defective. > > 1. It never heats up. > 2. The reference voltage is zero. > 3. Only noise is seen on the output pin. I had the same issue with some of them. It's very likely that the internal solder connections from pins to PCB are broken, at least, the one for power. It happens because the inner oven is heavy and there isn't any thermal insulator (besides air) to keep it from moving. Wheter the crystal has been damaged or not, it's unknown. I had one where the crystal actually fell off from its supports too. I posted a link to photos of the internals, time ago. The link is dead now and I don't think to have the photos anymore but perhaps someone downloaded them. Best regards, Andrea Baldoni

Hi Best guess is these things get taken off the board with either a big torch or a charcoal fire. You can ask Mr Google to dig up pictures of the process. Depending on just how quick they are, the insides of the OCXO can easily be reflowed. The likelihood of it reflowing and cooling back to a reliable joint … not real good. Bob > On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> wrote: > > On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: > >> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it, >> it is clear that it is defective. >> >> 1. It never heats up. >> 2. The reference voltage is zero. >> 3. Only noise is seen on the output pin. > > I had the same issue with some of them. It's very likely that the internal > solder connections from pins to PCB are broken, at least, the one for power. > It happens because the inner oven is heavy and there isn't any thermal > insulator (besides air) to keep it from moving. > > Wheter the crystal has been damaged or not, it's unknown. I had one where the > crystal actually fell off from its supports too. > > I posted a link to photos of the internals, time ago. The link is dead now > and I don't think to have the photos anymore but perhaps someone downloaded > them. > > Best regards, > Andrea Baldoni > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

Bob, In this case, I know how it was taken off the board - it wasn't. They just cut the board around it. I had to remove it myself. Nice thing about that, is that I got a nice plastic, pre-formed part that fits between the board and the OCXO, probably as an insulator. You are also right about the number of things that you need to test to make sure that one of these is fully functional. However, this is a "starter" OCXO for me and I don't yet have the equipment to perform the tests. The best that I can do is to make sure that, when powered up 1. I see something that sort of looks like a sine wave at a reasonable magnitude. 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. 3. If I apply gnd, or VRef to the adjustment pin I see the frequency change at least a small amount. Without more equipment, there isn't much more that I can do to test. Unless you have some suggestions? Mike > Hi > Best guess is these things get taken off the board with either a big torch or a charcoal fire. > You can ask Mr Google to dig up pictures of the process. Depending on just how quick > they are, the insides of the OCXO can easily be reflowed. The likelihood of it reflowing and > cooling back to a reliable joint … not real good. > Bob >> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> wrote: >> >> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >> >>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it, >>> it is clear that it is defective. >>> >>> 1. It never heats up. >>> 2. The reference voltage is zero. >>> 3. Only noise is seen on the output pin. >> >> I had the same issue with some of them. It's very likely that the internal >> solder connections from pins to PCB are broken, at least, the one for power. >> It happens because the inner oven is heavy and there isn't any thermal >> insulator (besides air) to keep it from moving. >> >> Wheter the crystal has been damaged or not, it's unknown. I had one where the >> crystal actually fell off from its supports too. >> >> I posted a link to photos of the internals, time ago. The link is dead now >> and I don't think to have the photos anymore but perhaps someone downloaded >> them. >> >> Best regards, >> Andrea Baldoni >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. -- Best regards, Timenut mailto:timenut@metachaos.net

 1. I see something that sort of looks like a sine wave at a reasonable
    magnitude.

 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz.

 3. If I apply gnd, or VRef to the adjustment pin I see the frequency change
    at least a small amount.

1. It never heats up.
2. The reference voltage is zero.
3. Only noise is seen on the output pin.

Hi Mike, look for any kind of radio-receiver, which would receive around 5MHz the old 60 meter broadcast ban, connect to power any kind of wire which could serve as antenna turn it on and try to find WWW at 5MHz, after that power up your 5MHz oscillator connect piece of wire to the 5 MHz output and bring the other end close to the radio receiver's "antenna" which you installed before. I you are lucky you will hear a beat from the radio's speaker, now you could apply some tuning voltage to your oscillator, and if you change that tuning voltage the beat will change somewhat but no to much since that OXCO has very narrow tuning range. I t could also happen that you do not hear any beat frequency, but a wabling [= very low frequency fluctuation] of the www, because your oscillator's and the frequency of the www are very close to each other, frequency of beat is not audible. the frequency of the www will be not exact since it's propagation path is not stabile. That is enough to see of the OXCO is still "alive" and with a proper PLL it could be tuned to the correct frequency 73 KJ6UHN Alex On 2/17/2016 6:56 PM, timenut@metachaos.net wrote: > Bob, > > In this case, I know how it was taken off the board - it wasn't. They just cut > the board around it. I had to remove it myself. Nice thing about that, is that > I got a nice plastic, pre-formed part that fits between the board and the > OCXO, probably as an insulator. > > You are also right about the number of things that you need to test to make > sure that one of these is fully functional. However, this is a "starter" OCXO > for me and I don't yet have the equipment to perform the tests. The best that > I can do is to make sure that, when powered up > > 1. I see something that sort of looks like a sine wave at a reasonable > magnitude. > > 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. > > 3. If I apply gnd, or VRef to the adjustment pin I see the frequency change > at least a small amount. > > Without more equipment, there isn't much more that I can do to test. Unless > you have some suggestions? > > > Mike > > >> Hi >> Best guess is these things get taken off the board with either a big torch or a charcoal fire. >> You can ask Mr Google to dig up pictures of the process. Depending on just how quick >> they are, the insides of the OCXO can easily be reflowed. The likelihood of it reflowing and >> cooling back to a reliable joint … not real good. >> Bob >>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> wrote: >>> >>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >>> >>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it, >>>> it is clear that it is defective. >>>> >>>> 1. It never heats up. >>>> 2. The reference voltage is zero. >>>> 3. Only noise is seen on the output pin. >>> I had the same issue with some of them. It's very likely that the internal >>> solder connections from pins to PCB are broken, at least, the one for power. >>> It happens because the inner oven is heavy and there isn't any thermal >>> insulator (besides air) to keep it from moving. >>> >>> Wheter the crystal has been damaged or not, it's unknown. I had one where the >>> crystal actually fell off from its supports too. >>> >>> I posted a link to photos of the internals, time ago. The link is dead now >>> and I don't think to have the photos anymore but perhaps someone downloaded >>> them. >>> >>> Best regards, >>> Andrea Baldoni >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > >

Hi It is *much* better to have an OCXO that you do not need to test to death. There is simply to much testing to do. A modern factory does not test the quality into the product (of any sort) they design in and build it in. The same is true of the normal customer for virtually any component. They make sure the parts come from somebody they can trust and save a lot of testing time. That said, yes, I have a pile of scrap parts sitting in front of me as I type this. It’s a hobby. Time does not count. It lets me play with all sorts of toys doing the testing. I occasionally learn things in the process. Mostly I learn that my hope of a 100% perfect batch is still a dream …. Bob > On Feb 17, 2016, at 9:56 PM, timenut@metachaos.net wrote: > > Bob, > > In this case, I know how it was taken off the board - it wasn't. They just cut > the board around it. I had to remove it myself. Nice thing about that, is that > I got a nice plastic, pre-formed part that fits between the board and the > OCXO, probably as an insulator. > > You are also right about the number of things that you need to test to make > sure that one of these is fully functional. However, this is a "starter" OCXO > for me and I don't yet have the equipment to perform the tests. The best that > I can do is to make sure that, when powered up > > 1. I see something that sort of looks like a sine wave at a reasonable > magnitude. > > 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. > > 3. If I apply gnd, or VRef to the adjustment pin I see the frequency change > at least a small amount. > > Without more equipment, there isn't much more that I can do to test. Unless > you have some suggestions? > > > Mike > > >> Hi > >> Best guess is these things get taken off the board with either a big torch or a charcoal fire. >> You can ask Mr Google to dig up pictures of the process. Depending on just how quick >> they are, the insides of the OCXO can easily be reflowed. The likelihood of it reflowing and >> cooling back to a reliable joint … not real good. > >> Bob > >>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> wrote: >>> >>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >>> >>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it, >>>> it is clear that it is defective. >>>> >>>> 1. It never heats up. >>>> 2. The reference voltage is zero. >>>> 3. Only noise is seen on the output pin. >>> >>> I had the same issue with some of them. It's very likely that the internal >>> solder connections from pins to PCB are broken, at least, the one for power. >>> It happens because the inner oven is heavy and there isn't any thermal >>> insulator (besides air) to keep it from moving. >>> >>> Wheter the crystal has been damaged or not, it's unknown. I had one where the >>> crystal actually fell off from its supports too. >>> >>> I posted a link to photos of the internals, time ago. The link is dead now >>> and I don't think to have the photos anymore but perhaps someone downloaded >>> them. >>> >>> Best regards, >>> Andrea Baldoni >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. > >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > > -- > Best regards, > Timenut mailto:timenut@metachaos.net > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

  at least a small amount.

I have a small collection of 10811 and similar oscillators here, collected from hamfests rather than china (and mostly pre-ebay). What sort of testing regime would you put them through ? I don't have anything as exotic as a timepod but I do have an HP53131A, the Tait Rb source, and a KS-24361 set up. And always keen to get hints on the acquisition of new toys ! On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp <kb8tq@n1k.org> wrote: > Hi > > It is *much* better to have an OCXO that you do not need to test to death. > There is simply to much testing to do. A modern factory does not test the > quality into the product (of any sort) they design in and build it in. The > same > is true of the normal customer for virtually any component. They make sure > the parts come from somebody they can trust and save a lot of testing time. > > That said, yes, I have a pile of scrap parts sitting in front of me as I > type this. > It’s a hobby. Time does not count. It lets me play with all sorts of toys > doing > the testing. I occasionally learn things in the process. Mostly I learn > that > my hope of a 100% perfect batch is still a dream …. > > Bob > > > > > On Feb 17, 2016, at 9:56 PM, timenut@metachaos.net wrote: > > > > Bob, > > > > In this case, I know how it was taken off the board - it wasn't. They > just cut > > the board around it. I had to remove it myself. Nice thing about that, > is that > > I got a nice plastic, pre-formed part that fits between the board and the > > OCXO, probably as an insulator. > > > > You are also right about the number of things that you need to test to > make > > sure that one of these is fully functional. However, this is a "starter" > OCXO > > for me and I don't yet have the equipment to perform the tests. The best > that > > I can do is to make sure that, when powered up > > > > 1. I see something that sort of looks like a sine wave at a reasonable > > magnitude. > > > > 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. > > > > 3. If I apply gnd, or VRef to the adjustment pin I see the frequency > change > > at least a small amount. > > > > Without more equipment, there isn't much more that I can do to test. > Unless > > you have some suggestions? > > > > > > Mike > > > > > >> Hi > > > >> Best guess is these things get taken off the board with either a big > torch or a charcoal fire. > >> You can ask Mr Google to dig up pictures of the process. Depending on > just how quick > >> they are, the insides of the OCXO can easily be reflowed. The > likelihood of it reflowing and > >> cooling back to a reliable joint … not real good. > > > >> Bob > > > >>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> > wrote: > >>> > >>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: > >>> > >>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After > testing it, > >>>> it is clear that it is defective. > >>>> > >>>> 1. It never heats up. > >>>> 2. The reference voltage is zero. > >>>> 3. Only noise is seen on the output pin. > >>> > >>> I had the same issue with some of them. It's very likely that the > internal > >>> solder connections from pins to PCB are broken, at least, the one for > power. > >>> It happens because the inner oven is heavy and there isn't any thermal > >>> insulator (besides air) to keep it from moving. > >>> > >>> Wheter the crystal has been damaged or not, it's unknown. I had one > where the > >>> crystal actually fell off from its supports too. > >>> > >>> I posted a link to photos of the internals, time ago. The link is dead > now > >>> and I don't think to have the photos anymore but perhaps someone > downloaded > >>> them. > >>> > >>> Best regards, > >>> Andrea Baldoni > >>> _______________________________________________ > >>> time-nuts mailing list -- time-nuts@febo.com > >>> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >>> and follow the instructions there. > > > >> _______________________________________________ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > > > > > > > > -- > > Best regards, > > Timenut mailto:timenut@metachaos.net > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. >

Bob is point on Said another way ...few of us consider the value of our time in these projects ..Lets say your personal time is worth $50/hour (cheap cheap for a professional today) let's say you have to spend 10 hours testing this oscillator that puts the real cost of the oscillator at $500+ .... suddenly some things don't look like such good bargains. The other side of the coin is that if you learn something new about oscillators and their behavior and the supporting electronics circuitry then $500 is a cheap educational seminar <grin>. Dave NR1DX On 2/18/2016 7:09 AM, Bob Camp wrote: > Hi > > It is*much* better to have an OCXO that you do not need to test to death. > There is simply to much testing to do. A modern factory does not test the > quality into the product (of any sort) they design in and build it in. The same > is true of the normal customer for virtually any component. They make sure > the parts come from somebody they can trust and save a lot of testing time. > > That said, yes, I have a pile of scrap parts sitting in front of me as I type this. > It’s a hobby. Time does not count. It lets me play with all sorts of toys doing > the testing. I occasionally learn things in the process. Mostly I learn that > my hope of a 100% perfect batch is still a dream …. > > Bob -- Dave Manuals@ArtekManuals.com www.ArtekManuals.com --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

 at least a small amount.

Hi The one advantage you have in testing a used OCXO is you have a pretty good idea of how you are going to use it. If phase noise does not matter to you … no need to test. I’d always check that it tunes on freq with reasonable EFC range left over. I’d also make sure that it warms up properly (oven works) and that it has a reasonable output. What goes on the list past that … it depends on what you need. The gear you have will check aging and get it set on frequency fine. It will check it for “wander” as your lab heats up and cools down. With a GPSDO and a simple phase lock, a DVM may be all you really need to do most of that. You will not have a proper ADEV, but you will know it works pretty well (or not ..). A lightbulb oven / bench / fridge /freezer proces can give you a wide range TC if you need it. If you do get into phase noise, a sound card system will get you going. For ADEV, the 10811’s tune far enough that a single mixer system with your 53131 will give you good data. Both of those will involve some building, but not a lot of money. There is one thing about the 10811’s: They are not sealed units. They tend to soak up humidity when stored in most parts of the country. You may want to run them for a month or three before doing any fancy testing. Bob > On Feb 18, 2016, at 7:40 AM, Adrian Godwin <artgodwin@gmail.com> wrote: > > I have a small collection of 10811 and similar oscillators here, collected > from hamfests rather than china (and mostly pre-ebay). > > What sort of testing regime would you put them through ? I don't have > anything as exotic as a timepod but I do have an HP53131A, the Tait Rb > source, and a KS-24361 set up. And always keen to get hints on the > acquisition of new toys ! > > > > On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp <kb8tq@n1k.org> wrote: > >> Hi >> >> It is *much* better to have an OCXO that you do not need to test to death. >> There is simply to much testing to do. A modern factory does not test the >> quality into the product (of any sort) they design in and build it in. The >> same >> is true of the normal customer for virtually any component. They make sure >> the parts come from somebody they can trust and save a lot of testing time. >> >> That said, yes, I have a pile of scrap parts sitting in front of me as I >> type this. >> It’s a hobby. Time does not count. It lets me play with all sorts of toys >> doing >> the testing. I occasionally learn things in the process. Mostly I learn >> that >> my hope of a 100% perfect batch is still a dream …. >> >> Bob >> >> >> >>> On Feb 17, 2016, at 9:56 PM, timenut@metachaos.net wrote: >>> >>> Bob, >>> >>> In this case, I know how it was taken off the board - it wasn't. They >> just cut >>> the board around it. I had to remove it myself. Nice thing about that, >> is that >>> I got a nice plastic, pre-formed part that fits between the board and the >>> OCXO, probably as an insulator. >>> >>> You are also right about the number of things that you need to test to >> make >>> sure that one of these is fully functional. However, this is a "starter" >> OCXO >>> for me and I don't yet have the equipment to perform the tests. The best >> that >>> I can do is to make sure that, when powered up >>> >>> 1. I see something that sort of looks like a sine wave at a reasonable >>> magnitude. >>> >>> 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. >>> >>> 3. If I apply gnd, or VRef to the adjustment pin I see the frequency >> change >>> at least a small amount. >>> >>> Without more equipment, there isn't much more that I can do to test. >> Unless >>> you have some suggestions? >>> >>> >>> Mike >>> >>> >>>> Hi >>> >>>> Best guess is these things get taken off the board with either a big >> torch or a charcoal fire. >>>> You can ask Mr Google to dig up pictures of the process. Depending on >> just how quick >>>> they are, the insides of the OCXO can easily be reflowed. The >> likelihood of it reflowing and >>>> cooling back to a reliable joint … not real good. >>> >>>> Bob >>> >>>>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> >> wrote: >>>>> >>>>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >>>>> >>>>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After >> testing it, >>>>>> it is clear that it is defective. >>>>>> >>>>>> 1. It never heats up. >>>>>> 2. The reference voltage is zero. >>>>>> 3. Only noise is seen on the output pin. >>>>> >>>>> I had the same issue with some of them. It's very likely that the >> internal >>>>> solder connections from pins to PCB are broken, at least, the one for >> power. >>>>> It happens because the inner oven is heavy and there isn't any thermal >>>>> insulator (besides air) to keep it from moving. >>>>> >>>>> Wheter the crystal has been damaged or not, it's unknown. I had one >> where the >>>>> crystal actually fell off from its supports too. >>>>> >>>>> I posted a link to photos of the internals, time ago. The link is dead >> now >>>>> and I don't think to have the photos anymore but perhaps someone >> downloaded >>>>> them. >>>>> >>>>> Best regards, >>>>> Andrea Baldoni >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> >>> >>> >>> -- >>> Best regards, >>> Timenut mailto:timenut@metachaos.net >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

 at least a small amount.

Bob, The vendor has said that they did not want the unit back. So... I opened it up. Crudely, I admit. I learned a few things. I was concerned about the outer case heating up too much when I was trying to remove the solder. Turns out that the outer case doesn't touch anything except the pins, so it can get pretty hot without any damage. Unfortunately, I used a bit of brute force to remove the casing after scraping away as much of the solder as I could and after cracking the solder seal with a hammer and screw driver. Even using more heat, I'm not sure of the best way to remove the case. Neither solder wick nor a vacuum desoldering tool is likely to remove all of the solder between the top case and the bottom. Even so, I got the case off. Somewhat bent, even bent the bottom circuit board a bit. I discovered that there is a 2mm hole in the top that allows a variable resistor to be adjusted. You need a pretty long, small screwdriver / adjusting tool to do that, but that is probably for setting the center point. I would try to remove the solder rather than drilling, or drill upside down to prevent solder flakes from falling inside. Also, I found that the -D on my part number appears to correspond to the board revision, which is marked "Rev D". So the -C and -D parts probably have the same specifications. And, on the inside there is a marking "92.0" which I believe would be the set point for this specific crystal. So if I took the crystal out, I would know where to design the set point for a custom unit (currently beyond my skills, but who knows...). From there, I removed the bottom casing. That caused additional damage, some lifted traces and even one very small part (tiny, SMD, who knows?). But, I then soldered wires directly to the board, making patches for the lifted traces. I plugged it in. I turned it on. Success! I gave it 12v which should supply 2A, but it dropped the voltage down to just over 9V. Even so, I got a nice sine wave out at around 4.999790Mhz according to my (uncalibrated) scope and around 800mV (into 50 ohm, DC). That was with nothing attached to the adjustment pin. After some time, the frequency stabilized at 5.000014Mhz and the voltage came back up to 10v. When I attached the adjustment pin to ground, there was no change. When I attached the adjustment pin to Vref (which is at 6.15v), the frequency dropped to 5.000010Mhz. So apparently, these units adjust negatively. But also have a very wide adjustment range of 4Hz (8e-7). I am assuming that the adjustment range is 0..6v. I attached the adjustment pin to +10v and the frequency dropped another 3Hz for a 1.4e-6 adjustment range. I don't expect that this specific unit will be very useful given the damage that I caused opening it up. But, probably there were just bad connections internally, so if I were much more careful in the disassembly, I could probably have fixed it. Something to keep in mind for the next unit. I may be wrong for what the variable resistor does. Turning it made no difference in the frequency. I also suspect, but don't know that the difference from 5Mhz is due to the frequency counter being uncalibrated. It could also because I damaged the unit or just because it is very far off from where it should be. Still, I learned a lot, and well worth the time spent. Mike > Hi > The one advantage you have in testing a used OCXO is you have a pretty good idea of how > you are going to use it. If phase noise does not matter to you … no need to test. I’d always check > that it tunes on freq with reasonable EFC range left over. I’d also make sure that it warms up > properly (oven works) and that it has a reasonable output. What goes on the list past that … > it depends on what you need. > The gear you have will check aging and get it set on frequency fine. It will check it for “wander” > as your lab heats up and cools down. With a GPSDO and a simple phase lock, a DVM may be > all you really need to do most of that. You will not have a proper ADEV, but you will know it works > pretty well (or not ..). > A lightbulb oven / bench / fridge /freezer proces can give you a wide range TC if you need it. > If you do get into phase noise, a sound card system will get you going. For ADEV, the 10811’s > tune far enough that a single mixer system with your 53131 will give you good data. Both > of those will involve some building, but not a lot of money. > There is one thing about the 10811’s: They are not sealed units. They tend to soak up humidity > when stored in most parts of the country. You may want to run them for a month or three > before doing any fancy testing. > Bob >> On Feb 18, 2016, at 7:40 AM, Adrian Godwin <artgodwin@gmail.com> wrote: >> >> I have a small collection of 10811 and similar oscillators here, collected >> from hamfests rather than china (and mostly pre-ebay). >> >> What sort of testing regime would you put them through ? I don't have >> anything as exotic as a timepod but I do have an HP53131A, the Tait Rb >> source, and a KS-24361 set up. And always keen to get hints on the >> acquisition of new toys ! >> >> >> >> On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp <kb8tq@n1k.org> wrote: >> >>> Hi >>> >>> It is *much* better to have an OCXO that you do not need to test to death. >>> There is simply to much testing to do. A modern factory does not test the >>> quality into the product (of any sort) they design in and build it in. The >>> same >>> is true of the normal customer for virtually any component. They make sure >>> the parts come from somebody they can trust and save a lot of testing time. >>> >>> That said, yes, I have a pile of scrap parts sitting in front of me as I >>> type this. >>> It’s a hobby. Time does not count. It lets me play with all sorts of toys >>> doing >>> the testing. I occasionally learn things in the process. Mostly I learn >>> that >>> my hope of a 100% perfect batch is still a dream …. >>> >>> Bob >>> >>> >>> >>>> On Feb 17, 2016, at 9:56 PM, timenut@metachaos.net wrote: >>>> >>>> Bob, >>>> >>>> In this case, I know how it was taken off the board - it wasn't. They >>> just cut >>>> the board around it. I had to remove it myself. Nice thing about that, >>> is that >>>> I got a nice plastic, pre-formed part that fits between the board and the >>>> OCXO, probably as an insulator. >>>> >>>> You are also right about the number of things that you need to test to >>> make >>>> sure that one of these is fully functional. However, this is a "starter" >>> OCXO >>>> for me and I don't yet have the equipment to perform the tests. The best >>> that >>>> I can do is to make sure that, when powered up >>>> >>>> 1. I see something that sort of looks like a sine wave at a reasonable >>>> magnitude. >>>> >>>> 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. >>>> >>>> 3. If I apply gnd, or VRef to the adjustment pin I see the frequency >>> change >>>> at least a small amount. >>>> >>>> Without more equipment, there isn't much more that I can do to test. >>> Unless >>>> you have some suggestions? >>>> >>>> >>>> Mike >>>> >>>> >>>>> Hi >>>> >>>>> Best guess is these things get taken off the board with either a big >>> torch or a charcoal fire. >>>>> You can ask Mr Google to dig up pictures of the process. Depending on >>> just how quick >>>>> they are, the insides of the OCXO can easily be reflowed. The >>> likelihood of it reflowing and >>>>> cooling back to a reliable joint … not real good. >>>> >>>>> Bob >>>> >>>>>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> >>> wrote: >>>>>> >>>>>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >>>>>> >>>>>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After >>> testing it, >>>>>>> it is clear that it is defective. >>>>>>> >>>>>>> 1. It never heats up. >>>>>>> 2. The reference voltage is zero. >>>>>>> 3. Only noise is seen on the output pin. >>>>>> >>>>>> I had the same issue with some of them. It's very likely that the >>> internal >>>>>> solder connections from pins to PCB are broken, at least, the one for >>> power. >>>>>> It happens because the inner oven is heavy and there isn't any thermal >>>>>> insulator (besides air) to keep it from moving. >>>>>> >>>>>> Wheter the crystal has been damaged or not, it's unknown. I had one >>> where the >>>>>> crystal actually fell off from its supports too. >>>>>> >>>>>> I posted a link to photos of the internals, time ago. The link is dead >>> now >>>>>> and I don't think to have the photos anymore but perhaps someone >>> downloaded >>>>>> them. >>>>>> >>>>>> Best regards, >>>>>> Andrea Baldoni >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>> >>>> >>>> >>>> -- >>>> Best regards, >>>> Timenut mailto:timenut@metachaos.net >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. -- Best regards, Timenut mailto:timenut@metachaos.net

  at least a small amount.

Hi Mike, Would you be so kindly and post some pictures of the opening process of that OCSXO ? 73 KJ6UHN Alex On 2/18/2016 7:54 PM, timenut@metachaos.net wrote: > Bob, > > The vendor has said that they did not want the unit back. So... > > I opened it up. Crudely, I admit. I learned a few things. I was concerned > about the outer case heating up too much when I was trying to remove the > solder. Turns out that the outer case doesn't touch anything except the pins, > so it can get pretty hot without any damage. Unfortunately, I used a bit of > brute force to remove the casing after scraping away as much of the solder as > I could and after cracking the solder seal with a hammer and screw driver. > Even using more heat, I'm not sure of the best way to remove the case. Neither > solder wick nor a vacuum desoldering tool is likely to remove all of the > solder between the top case and the bottom. > > Even so, I got the case off. Somewhat bent, even bent the bottom circuit board > a bit. I discovered that there is a 2mm hole in the top that allows a variable > resistor to be adjusted. You need a pretty long, small screwdriver / adjusting > tool to do that, but that is probably for setting the center point. I would > try to remove the solder rather than drilling, or drill upside down to prevent > solder flakes from falling inside. > > Also, I found that the -D on my part number appears to correspond to the board > revision, which is marked "Rev D". So the -C and -D parts probably have the > same specifications. And, on the inside there is a marking "92.0" which I > believe would be the set point for this specific crystal. So if I took the > crystal out, I would know where to design the set point for a custom unit > (currently beyond my skills, but who knows...). > > From there, I removed the bottom casing. That caused additional damage, some > lifted traces and even one very small part (tiny, SMD, who knows?). > > But, I then soldered wires directly to the board, making patches for the > lifted traces. > > I plugged it in. > > I turned it on. > > Success! > > I gave it 12v which should supply 2A, but it dropped the voltage down to just > over 9V. Even so, I got a nice sine wave out at around 4.999790Mhz according > to my (uncalibrated) scope and around 800mV (into 50 ohm, DC). That was with > nothing attached to the adjustment pin. After some time, the frequency > stabilized at 5.000014Mhz and the voltage came back up to 10v. When I attached > the adjustment pin to ground, there was no change. When I attached the > adjustment pin to Vref (which is at 6.15v), the frequency dropped to > 5.000010Mhz. So apparently, these units adjust negatively. But also have a > very wide adjustment range of 4Hz (8e-7). I am assuming that the adjustment > range is 0..6v. I attached the adjustment pin to +10v and the frequency > dropped another 3Hz for a 1.4e-6 adjustment range. > > I don't expect that this specific unit will be very useful given the damage > that I caused opening it up. But, probably there were just bad connections > internally, so if I were much more careful in the disassembly, I could > probably have fixed it. Something to keep in mind for the next unit. > > I may be wrong for what the variable resistor does. Turning it made no > difference in the frequency. > > I also suspect, but don't know that the difference from 5Mhz is due to the > frequency counter being uncalibrated. It could also because I damaged the unit > or just because it is very far off from where it should be. > > Still, I learned a lot, and well worth the time spent. > > > Mike > > >> Hi >> The one advantage you have in testing a used OCXO is you have a pretty good idea of how >> you are going to use it. If phase noise does not matter to you … no need to test. I’d always check >> that it tunes on freq with reasonable EFC range left over. I’d also make sure that it warms up >> properly (oven works) and that it has a reasonable output. What goes on the list past that … >> it depends on what you need. >> The gear you have will check aging and get it set on frequency fine. It will check it for “wander” >> as your lab heats up and cools down. With a GPSDO and a simple phase lock, a DVM may be >> all you really need to do most of that. You will not have a proper ADEV, but you will know it works >> pretty well (or not ..). >> A lightbulb oven / bench / fridge /freezer proces can give you a wide range TC if you need it. >> If you do get into phase noise, a sound card system will get you going. For ADEV, the 10811’s >> tune far enough that a single mixer system with your 53131 will give you good data. Both >> of those will involve some building, but not a lot of money. >> There is one thing about the 10811’s: They are not sealed units. They tend to soak up humidity >> when stored in most parts of the country. You may want to run them for a month or three >> before doing any fancy testing. >> Bob >>> On Feb 18, 2016, at 7:40 AM, Adrian Godwin <artgodwin@gmail.com> wrote: >>> >>> I have a small collection of 10811 and similar oscillators here, collected >>> from hamfests rather than china (and mostly pre-ebay). >>> >>> What sort of testing regime would you put them through ? I don't have >>> anything as exotic as a timepod but I do have an HP53131A, the Tait Rb >>> source, and a KS-24361 set up. And always keen to get hints on the >>> acquisition of new toys ! >>> >>> >>> >>> On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp <kb8tq@n1k.org> wrote: >>> >>>> Hi >>>> >>>> It is *much* better to have an OCXO that you do not need to test to death. >>>> There is simply to much testing to do. A modern factory does not test the >>>> quality into the product (of any sort) they design in and build it in. The >>>> same >>>> is true of the normal customer for virtually any component. They make sure >>>> the parts come from somebody they can trust and save a lot of testing time. >>>> >>>> That said, yes, I have a pile of scrap parts sitting in front of me as I >>>> type this. >>>> It’s a hobby. Time does not count. It lets me play with all sorts of toys >>>> doing >>>> the testing. I occasionally learn things in the process. Mostly I learn >>>> that >>>> my hope of a 100% perfect batch is still a dream …. >>>> >>>> Bob >>>> >>>> >>>> >>>>> On Feb 17, 2016, at 9:56 PM, timenut@metachaos.net wrote: >>>>> >>>>> Bob, >>>>> >>>>> In this case, I know how it was taken off the board - it wasn't. They >>>> just cut >>>>> the board around it. I had to remove it myself. Nice thing about that, >>>> is that >>>>> I got a nice plastic, pre-formed part that fits between the board and the >>>>> OCXO, probably as an insulator. >>>>> >>>>> You are also right about the number of things that you need to test to >>>> make >>>>> sure that one of these is fully functional. However, this is a "starter" >>>> OCXO >>>>> for me and I don't yet have the equipment to perform the tests. The best >>>> that >>>>> I can do is to make sure that, when powered up >>>>> >>>>> 1. I see something that sort of looks like a sine wave at a reasonable >>>>> magnitude. >>>>> >>>>> 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. >>>>> >>>>> 3. If I apply gnd, or VRef to the adjustment pin I see the frequency >>>> change >>>>> at least a small amount. >>>>> >>>>> Without more equipment, there isn't much more that I can do to test. >>>> Unless >>>>> you have some suggestions? >>>>> >>>>> >>>>> Mike >>>>> >>>>> >>>>>> Hi >>>>>> Best guess is these things get taken off the board with either a big >>>> torch or a charcoal fire. >>>>>> You can ask Mr Google to dig up pictures of the process. Depending on >>>> just how quick >>>>>> they are, the insides of the OCXO can easily be reflowed. The >>>> likelihood of it reflowing and >>>>>> cooling back to a reliable joint … not real good. >>>>>> Bob >>>>>>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> >>>> wrote: >>>>>>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >>>>>>> >>>>>>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After >>>> testing it, >>>>>>>> it is clear that it is defective. >>>>>>>> >>>>>>>> 1. It never heats up. >>>>>>>> 2. The reference voltage is zero. >>>>>>>> 3. Only noise is seen on the output pin. >>>>>>> I had the same issue with some of them. It's very likely that the >>>> internal >>>>>>> solder connections from pins to PCB are broken, at least, the one for >>>> power. >>>>>>> It happens because the inner oven is heavy and there isn't any thermal >>>>>>> insulator (besides air) to keep it from moving. >>>>>>> >>>>>>> Wheter the crystal has been damaged or not, it's unknown. I had one >>>> where the >>>>>>> crystal actually fell off from its supports too. >>>>>>> >>>>>>> I posted a link to photos of the internals, time ago. The link is dead >>>> now >>>>>>> and I don't think to have the photos anymore but perhaps someone >>>> downloaded >>>>>>> them. >>>>>>> >>>>>>> Best regards, >>>>>>> Andrea Baldoni >>>>>>> _______________________________________________ >>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>> and follow the instructions there. >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>>> >>>>> >>>>> -- >>>>> Best regards, >>>>> Timenut mailto:timenut@metachaos.net >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > >

  at least a small amount.

Alex, I did not take opening pictures, but there is nothing to miss. For the outside of the unopened case, there are plenty of pictures on eBay. For the actual opening process, that consisted largely of scraping away solder with a small, triangular file and utility knife until most of what I could remove was gone and then using a hammer and screwdriver to separate the sides from the bottom and then prying it off. Nothing pretty, and nothing much for pictures. I used a tiny drill for my desoldering gun to remove an intial hole in the solder for the adjustment hole. I then enlarged it with a 1/16th drill bit (by hand). Ideally, a 2mm drill bit could be used. A 5/64th drill bit will fit through the hole, but it is very tight. Probably not best to drill with it because that would most likely enlarge the hole. I wouldn't open it the same way again, but I'm not sure of the best procedure that leaves the case and contents undamaged so that it can be reassembled. I think, perhaps, that I would remove all of the solder that I could as before. But then, I would make some sort of cut-out for the pins on the bottom and put it in a pan on the stove and heat it up (hopefully, evenly) until the bottom could be popped off. The outside case can get pretty hot without damage because the only contact is the pins and the inside gets pretty hot when running. The main risk is getting so hot that the plastic spacers on the pins melt or the pin supports melt. I'm not sure how hot that would be. But, they must have heated it fairly hot to melt the solder originally, so hopefully that would work. However, here are some pictures of the inside :) which is probably what you want! Top Case 1: [img]http://imgur.com/mvQkJ16[/img] Top Case 2: [img]http://imgur.com/K7Rmeau[/img] Bottom Case 1: [img]http://imgur.com/j7tC7QN[/img] Bottom Case 2: [img]http://imgur.com/TKiofvi[/img] Outer Oven 1: [img]http://imgur.com/bzYywj7[/img] Outer Oven 2: [img]http://imgur.com/kKKynzc[/img] Outer Oven 3: [img]http://imgur.com/xtzFsXD[/img] Circuit Board: [img]http://imgur.com/PHgnVIm[/img] Mike > Hi Mike, > Would you be so kindly and post some pictures of the opening process of > that OCSXO ? > 73 > KJ6UHN > Alex > On 2/18/2016 7:54 PM, timenut@metachaos.net wrote: >> Bob, >> >> The vendor has said that they did not want the unit back. So... >> >> I opened it up. Crudely, I admit. I learned a few things. I was concerned >> about the outer case heating up too much when I was trying to remove the >> solder. Turns out that the outer case doesn't touch anything except the pins, >> so it can get pretty hot without any damage. Unfortunately, I used a bit of >> brute force to remove the casing after scraping away as much of the solder as >> I could and after cracking the solder seal with a hammer and screw driver. >> Even using more heat, I'm not sure of the best way to remove the case. Neither >> solder wick nor a vacuum desoldering tool is likely to remove all of the >> solder between the top case and the bottom. >> >> Even so, I got the case off. Somewhat bent, even bent the bottom circuit board >> a bit. I discovered that there is a 2mm hole in the top that allows a variable >> resistor to be adjusted. You need a pretty long, small screwdriver / adjusting >> tool to do that, but that is probably for setting the center point. I would >> try to remove the solder rather than drilling, or drill upside down to prevent >> solder flakes from falling inside. >> >> Also, I found that the -D on my part number appears to correspond to the board >> revision, which is marked "Rev D". So the -C and -D parts probably have the >> same specifications. And, on the inside there is a marking "92.0" which I >> believe would be the set point for this specific crystal. So if I took the >> crystal out, I would know where to design the set point for a custom unit >> (currently beyond my skills, but who knows...). >> >> From there, I removed the bottom casing. That caused additional damage, some >> lifted traces and even one very small part (tiny, SMD, who knows?). >> >> But, I then soldered wires directly to the board, making patches for the >> lifted traces. >> >> I plugged it in. >> >> I turned it on. >> >> Success! >> >> I gave it 12v which should supply 2A, but it dropped the voltage down to just >> over 9V. Even so, I got a nice sine wave out at around 4.999790Mhz according >> to my (uncalibrated) scope and around 800mV (into 50 ohm, DC). That was with >> nothing attached to the adjustment pin. After some time, the frequency >> stabilized at 5.000014Mhz and the voltage came back up to 10v. When I attached >> the adjustment pin to ground, there was no change. When I attached the >> adjustment pin to Vref (which is at 6.15v), the frequency dropped to >> 5.000010Mhz. So apparently, these units adjust negatively. But also have a >> very wide adjustment range of 4Hz (8e-7). I am assuming that the adjustment >> range is 0..6v. I attached the adjustment pin to +10v and the frequency >> dropped another 3Hz for a 1.4e-6 adjustment range. >> >> I don't expect that this specific unit will be very useful given the damage >> that I caused opening it up. But, probably there were just bad connections >> internally, so if I were much more careful in the disassembly, I could >> probably have fixed it. Something to keep in mind for the next unit. >> >> I may be wrong for what the variable resistor does. Turning it made no >> difference in the frequency. >> >> I also suspect, but don't know that the difference from 5Mhz is due to the >> frequency counter being uncalibrated. It could also because I damaged the unit >> or just because it is very far off from where it should be. >> >> Still, I learned a lot, and well worth the time spent. >> >> >> Mike >> >> >>> Hi >>> The one advantage you have in testing a used OCXO is you have a pretty good idea of how >>> you are going to use it. If phase noise does not matter to you … no need to test. I’d always check >>> that it tunes on freq with reasonable EFC range left over. I’d also make sure that it warms up >>> properly (oven works) and that it has a reasonable output. What goes on the list past that … >>> it depends on what you need. >>> The gear you have will check aging and get it set on frequency fine. It will check it for “wander” >>> as your lab heats up and cools down. With a GPSDO and a simple phase lock, a DVM may be >>> all you really need to do most of that. You will not have a proper ADEV, but you will know it works >>> pretty well (or not ..). >>> A lightbulb oven / bench / fridge /freezer proces can give you a wide range TC if you need it. >>> If you do get into phase noise, a sound card system will get you going. For ADEV, the 10811’s >>> tune far enough that a single mixer system with your 53131 will give you good data. Both >>> of those will involve some building, but not a lot of money. >>> There is one thing about the 10811’s: They are not sealed units. They tend to soak up humidity >>> when stored in most parts of the country. You may want to run them for a month or three >>> before doing any fancy testing. >>> Bob >>>> On Feb 18, 2016, at 7:40 AM, Adrian Godwin <artgodwin@gmail.com> wrote: >>>> >>>> I have a small collection of 10811 and similar oscillators here, collected >>>> from hamfests rather than china (and mostly pre-ebay). >>>> >>>> What sort of testing regime would you put them through ? I don't have >>>> anything as exotic as a timepod but I do have an HP53131A, the Tait Rb >>>> source, and a KS-24361 set up. And always keen to get hints on the >>>> acquisition of new toys ! >>>> >>>> >>>> >>>> On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp <kb8tq@n1k.org> wrote: >>>> >>>>> Hi >>>>> >>>>> It is *much* better to have an OCXO that you do not need to test to death. >>>>> There is simply to much testing to do. A modern factory does not test the >>>>> quality into the product (of any sort) they design in and build it in. The >>>>> same >>>>> is true of the normal customer for virtually any component. They make sure >>>>> the parts come from somebody they can trust and save a lot of testing time. >>>>> >>>>> That said, yes, I have a pile of scrap parts sitting in front of me as I >>>>> type this. >>>>> It’s a hobby. Time does not count. It lets me play with all sorts of toys >>>>> doing >>>>> the testing. I occasionally learn things in the process. Mostly I learn >>>>> that >>>>> my hope of a 100% perfect batch is still a dream …. >>>>> >>>>> Bob >>>>> >>>>> >>>>> >>>>>> On Feb 17, 2016, at 9:56 PM, timenut@metachaos.net wrote: >>>>>> >>>>>> Bob, >>>>>> >>>>>> In this case, I know how it was taken off the board - it wasn't. They >>>>> just cut >>>>>> the board around it. I had to remove it myself. Nice thing about that, >>>>> is that >>>>>> I got a nice plastic, pre-formed part that fits between the board and the >>>>>> OCXO, probably as an insulator. >>>>>> >>>>>> You are also right about the number of things that you need to test to >>>>> make >>>>>> sure that one of these is fully functional. However, this is a "starter" >>>>> OCXO >>>>>> for me and I don't yet have the equipment to perform the tests. The best >>>>> that >>>>>> I can do is to make sure that, when powered up >>>>>> >>>>>> 1. I see something that sort of looks like a sine wave at a reasonable >>>>>> magnitude. >>>>>> >>>>>> 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. >>>>>> >>>>>> 3. If I apply gnd, or VRef to the adjustment pin I see the frequency >>>>> change >>>>>> at least a small amount. >>>>>> >>>>>> Without more equipment, there isn't much more that I can do to test. >>>>> Unless >>>>>> you have some suggestions? >>>>>> >>>>>> >>>>>> Mike >>>>>> >>>>>> >>>>>>> Hi >>>>>>> Best guess is these things get taken off the board with either a big >>>>> torch or a charcoal fire. >>>>>>> You can ask Mr Google to dig up pictures of the process. Depending on >>>>> just how quick >>>>>>> they are, the insides of the OCXO can easily be reflowed. The >>>>> likelihood of it reflowing and >>>>>>> cooling back to a reliable joint … not real good. >>>>>>> Bob >>>>>>>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> >>>>> wrote: >>>>>>>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >>>>>>>> >>>>>>>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After >>>>> testing it, >>>>>>>>> it is clear that it is defective. >>>>>>>>> >>>>>>>>> 1. It never heats up. >>>>>>>>> 2. The reference voltage is zero. >>>>>>>>> 3. Only noise is seen on the output pin. >>>>>>>> I had the same issue with some of them. It's very likely that the >>>>> internal >>>>>>>> solder connections from pins to PCB are broken, at least, the one for >>>>> power. >>>>>>>> It happens because the inner oven is heavy and there isn't any thermal >>>>>>>> insulator (besides air) to keep it from moving. >>>>>>>> >>>>>>>> Wheter the crystal has been damaged or not, it's unknown. I had one >>>>> where the >>>>>>>> crystal actually fell off from its supports too. >>>>>>>> >>>>>>>> I posted a link to photos of the internals, time ago. The link is dead >>>>> now >>>>>>>> and I don't think to have the photos anymore but perhaps someone >>>>> downloaded >>>>>>>> them. >>>>>>>> >>>>>>>> Best regards, >>>>>>>> Andrea Baldoni >>>>>>>> _______________________________________________ >>>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>>> and follow the instructions there. >>>>>>> _______________________________________________ >>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>> and follow the instructions there. >>>>>> >>>>>> >>>>>> -- >>>>>> Best regards, >>>>>> Timenut mailto:timenut@metachaos.net >>>>>> >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> -- Best regards, Timenut mailto:timenut@metachaos.net

 at least a small amount.

Hi The neatest thing I’ve seen to open an OCXO is a big old gizmo made by Lepell(??). Roughly a 3’ high rack enclosure. Inside you had a ~ 1KW MOPA transmitter at “sort of 13 MHz”. You tuned the thing into a copper tube wrapped around the OCXO base. The net result was that the RF all went into losses in the steel can / base. The whole thing heated up in no time at all. No idea where it came from or how old it was. In some cases the only real way to get one open is to “peel” the can off the base. Get a *good* set of gloves if you try to do this. The can is trash, but in theory, the base and the guts are in fine shape. Not quite clear what you do for a new can if you want to put it back together. Bob > On Feb 19, 2016, at 12:09 PM, timenut@metachaos.net wrote: > > Alex, > > I did not take opening pictures, but there is nothing to miss. > > For the outside of the unopened case, there are plenty of pictures on eBay. > For the actual opening process, that consisted largely of scraping away solder > with a small, triangular file and utility knife until most of what I could > remove was gone and then using a hammer and screwdriver to separate the sides > from the bottom and then prying it off. Nothing pretty, and nothing much for > pictures. I used a tiny drill for my desoldering gun to remove an intial hole > in the solder for the adjustment hole. I then enlarged it with a 1/16th drill > bit (by hand). Ideally, a 2mm drill bit could be used. A 5/64th drill bit will > fit through the hole, but it is very tight. Probably not best to drill with > it because that would most likely enlarge the hole. > > I wouldn't open it the same way again, but I'm not sure of the best procedure > that leaves the case and contents undamaged so that it can be reassembled. I > think, perhaps, that I would remove all of the solder that I could as before. > But then, I would make some sort of cut-out for the pins on the bottom and put > it in a pan on the stove and heat it up (hopefully, evenly) until the bottom > could be popped off. The outside case can get pretty hot without damage > because the only contact is the pins and the inside gets pretty hot when > running. The main risk is getting so hot that the plastic spacers on the pins > melt or the pin supports melt. I'm not sure how hot that would be. But, they > must have heated it fairly hot to melt the solder originally, so hopefully > that would work. > > However, here are some pictures of the inside :) which is probably what you > want! > > Top Case 1: [img]http://imgur.com/mvQkJ16[/img] > Top Case 2: [img]http://imgur.com/K7Rmeau[/img] > Bottom Case 1: [img]http://imgur.com/j7tC7QN[/img] > Bottom Case 2: [img]http://imgur.com/TKiofvi[/img] > Outer Oven 1: [img]http://imgur.com/bzYywj7[/img] > Outer Oven 2: [img]http://imgur.com/kKKynzc[/img] > Outer Oven 3: [img]http://imgur.com/xtzFsXD[/img] > Circuit Board: [img]http://imgur.com/PHgnVIm[/img] > > > Mike > > >> Hi Mike, >> Would you be so kindly and post some pictures of the opening process of >> that OCSXO ? >> 73 >> KJ6UHN >> Alex >> On 2/18/2016 7:54 PM, timenut@metachaos.net wrote: >>> Bob, >>> >>> The vendor has said that they did not want the unit back. So... >>> >>> I opened it up. Crudely, I admit. I learned a few things. I was concerned >>> about the outer case heating up too much when I was trying to remove the >>> solder. Turns out that the outer case doesn't touch anything except the pins, >>> so it can get pretty hot without any damage. Unfortunately, I used a bit of >>> brute force to remove the casing after scraping away as much of the solder as >>> I could and after cracking the solder seal with a hammer and screw driver. >>> Even using more heat, I'm not sure of the best way to remove the case. Neither >>> solder wick nor a vacuum desoldering tool is likely to remove all of the >>> solder between the top case and the bottom. >>> >>> Even so, I got the case off. Somewhat bent, even bent the bottom circuit board >>> a bit. I discovered that there is a 2mm hole in the top that allows a variable >>> resistor to be adjusted. You need a pretty long, small screwdriver / adjusting >>> tool to do that, but that is probably for setting the center point. I would >>> try to remove the solder rather than drilling, or drill upside down to prevent >>> solder flakes from falling inside. >>> >>> Also, I found that the -D on my part number appears to correspond to the board >>> revision, which is marked "Rev D". So the -C and -D parts probably have the >>> same specifications. And, on the inside there is a marking "92.0" which I >>> believe would be the set point for this specific crystal. So if I took the >>> crystal out, I would know where to design the set point for a custom unit >>> (currently beyond my skills, but who knows...). >>> >>> From there, I removed the bottom casing. That caused additional damage, some >>> lifted traces and even one very small part (tiny, SMD, who knows?). >>> >>> But, I then soldered wires directly to the board, making patches for the >>> lifted traces. >>> >>> I plugged it in. >>> >>> I turned it on. >>> >>> Success! >>> >>> I gave it 12v which should supply 2A, but it dropped the voltage down to just >>> over 9V. Even so, I got a nice sine wave out at around 4.999790Mhz according >>> to my (uncalibrated) scope and around 800mV (into 50 ohm, DC). That was with >>> nothing attached to the adjustment pin. After some time, the frequency >>> stabilized at 5.000014Mhz and the voltage came back up to 10v. When I attached >>> the adjustment pin to ground, there was no change. When I attached the >>> adjustment pin to Vref (which is at 6.15v), the frequency dropped to >>> 5.000010Mhz. So apparently, these units adjust negatively. But also have a >>> very wide adjustment range of 4Hz (8e-7). I am assuming that the adjustment >>> range is 0..6v. I attached the adjustment pin to +10v and the frequency >>> dropped another 3Hz for a 1.4e-6 adjustment range. >>> >>> I don't expect that this specific unit will be very useful given the damage >>> that I caused opening it up. But, probably there were just bad connections >>> internally, so if I were much more careful in the disassembly, I could >>> probably have fixed it. Something to keep in mind for the next unit. >>> >>> I may be wrong for what the variable resistor does. Turning it made no >>> difference in the frequency. >>> >>> I also suspect, but don't know that the difference from 5Mhz is due to the >>> frequency counter being uncalibrated. It could also because I damaged the unit >>> or just because it is very far off from where it should be. >>> >>> Still, I learned a lot, and well worth the time spent. >>> >>> >>> Mike >>> >>> >>>> Hi >>>> The one advantage you have in testing a used OCXO is you have a pretty good idea of how >>>> you are going to use it. If phase noise does not matter to you … no need to test. I’d always check >>>> that it tunes on freq with reasonable EFC range left over. I’d also make sure that it warms up >>>> properly (oven works) and that it has a reasonable output. What goes on the list past that … >>>> it depends on what you need. >>>> The gear you have will check aging and get it set on frequency fine. It will check it for “wander” >>>> as your lab heats up and cools down. With a GPSDO and a simple phase lock, a DVM may be >>>> all you really need to do most of that. You will not have a proper ADEV, but you will know it works >>>> pretty well (or not ..). >>>> A lightbulb oven / bench / fridge /freezer proces can give you a wide range TC if you need it. >>>> If you do get into phase noise, a sound card system will get you going. For ADEV, the 10811’s >>>> tune far enough that a single mixer system with your 53131 will give you good data. Both >>>> of those will involve some building, but not a lot of money. >>>> There is one thing about the 10811’s: They are not sealed units. They tend to soak up humidity >>>> when stored in most parts of the country. You may want to run them for a month or three >>>> before doing any fancy testing. >>>> Bob >>>>> On Feb 18, 2016, at 7:40 AM, Adrian Godwin <artgodwin@gmail.com> wrote: >>>>> >>>>> I have a small collection of 10811 and similar oscillators here, collected >>>>> from hamfests rather than china (and mostly pre-ebay). >>>>> >>>>> What sort of testing regime would you put them through ? I don't have >>>>> anything as exotic as a timepod but I do have an HP53131A, the Tait Rb >>>>> source, and a KS-24361 set up. And always keen to get hints on the >>>>> acquisition of new toys ! >>>>> >>>>> >>>>> >>>>> On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp <kb8tq@n1k.org> wrote: >>>>> >>>>>> Hi >>>>>> >>>>>> It is *much* better to have an OCXO that you do not need to test to death. >>>>>> There is simply to much testing to do. A modern factory does not test the >>>>>> quality into the product (of any sort) they design in and build it in. The >>>>>> same >>>>>> is true of the normal customer for virtually any component. They make sure >>>>>> the parts come from somebody they can trust and save a lot of testing time. >>>>>> >>>>>> That said, yes, I have a pile of scrap parts sitting in front of me as I >>>>>> type this. >>>>>> It’s a hobby. Time does not count. It lets me play with all sorts of toys >>>>>> doing >>>>>> the testing. I occasionally learn things in the process. Mostly I learn >>>>>> that >>>>>> my hope of a 100% perfect batch is still a dream …. >>>>>> >>>>>> Bob >>>>>> >>>>>> >>>>>> >>>>>>> On Feb 17, 2016, at 9:56 PM, timenut@metachaos.net wrote: >>>>>>> >>>>>>> Bob, >>>>>>> >>>>>>> In this case, I know how it was taken off the board - it wasn't. They >>>>>> just cut >>>>>>> the board around it. I had to remove it myself. Nice thing about that, >>>>>> is that >>>>>>> I got a nice plastic, pre-formed part that fits between the board and the >>>>>>> OCXO, probably as an insulator. >>>>>>> >>>>>>> You are also right about the number of things that you need to test to >>>>>> make >>>>>>> sure that one of these is fully functional. However, this is a "starter" >>>>>> OCXO >>>>>>> for me and I don't yet have the equipment to perform the tests. The best >>>>>> that >>>>>>> I can do is to make sure that, when powered up >>>>>>> >>>>>>> 1. I see something that sort of looks like a sine wave at a reasonable >>>>>>> magnitude. >>>>>>> >>>>>>> 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. >>>>>>> >>>>>>> 3. If I apply gnd, or VRef to the adjustment pin I see the frequency >>>>>> change >>>>>>> at least a small amount. >>>>>>> >>>>>>> Without more equipment, there isn't much more that I can do to test. >>>>>> Unless >>>>>>> you have some suggestions? >>>>>>> >>>>>>> >>>>>>> Mike >>>>>>> >>>>>>> >>>>>>>> Hi >>>>>>>> Best guess is these things get taken off the board with either a big >>>>>> torch or a charcoal fire. >>>>>>>> You can ask Mr Google to dig up pictures of the process. Depending on >>>>>> just how quick >>>>>>>> they are, the insides of the OCXO can easily be reflowed. The >>>>>> likelihood of it reflowing and >>>>>>>> cooling back to a reliable joint … not real good. >>>>>>>> Bob >>>>>>>>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> >>>>>> wrote: >>>>>>>>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >>>>>>>>> >>>>>>>>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After >>>>>> testing it, >>>>>>>>>> it is clear that it is defective. >>>>>>>>>> >>>>>>>>>> 1. It never heats up. >>>>>>>>>> 2. The reference voltage is zero. >>>>>>>>>> 3. Only noise is seen on the output pin. >>>>>>>>> I had the same issue with some of them. It's very likely that the >>>>>> internal >>>>>>>>> solder connections from pins to PCB are broken, at least, the one for >>>>>> power. >>>>>>>>> It happens because the inner oven is heavy and there isn't any thermal >>>>>>>>> insulator (besides air) to keep it from moving. >>>>>>>>> >>>>>>>>> Wheter the crystal has been damaged or not, it's unknown. I had one >>>>>> where the >>>>>>>>> crystal actually fell off from its supports too. >>>>>>>>> >>>>>>>>> I posted a link to photos of the internals, time ago. The link is dead >>>>>> now >>>>>>>>> and I don't think to have the photos anymore but perhaps someone >>>>>> downloaded >>>>>>>>> them. >>>>>>>>> >>>>>>>>> Best regards, >>>>>>>>> Andrea Baldoni >>>>>>>>> _______________________________________________ >>>>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>>>> and follow the instructions there. >>>>>>>> _______________________________________________ >>>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>>> and follow the instructions there. >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Best regards, >>>>>>> Timenut mailto:timenut@metachaos.net >>>>>>> >>>>>>> _______________________________________________ >>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>> and follow the instructions there. >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> >>> > > > > > -- > Best regards, > Timenut mailto:timenut@metachaos.net > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

1. I see something that sort of looks like a sine wave at a reasonable
   magnitude.

2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz.

3. If I apply gnd, or VRef to the adjustment pin I see the frequency

   at least a small amount.

I have read sometime ago and probably on this list a success stories about opening OCXOs using a hot air gun or even a propane torch, an x-acto knife and a stainless steel shim sheet to avoid the solder to do it stuff again when solidifying. Using this technique probably the can could be reused after repairing the part. Ignacio EB4APL El 19/02/2016 a las 18:09, timenut@metachaos.net wrote: > Alex, > > I did not take opening pictures, but there is nothing to miss. > > For the outside of the unopened case, there are plenty of pictures on eBay. > For the actual opening process, that consisted largely of scraping away solder > with a small, triangular file and utility knife until most of what I could > remove was gone and then using a hammer and screwdriver to separate the sides > from the bottom and then prying it off. Nothing pretty, and nothing much for > pictures. I used a tiny drill for my desoldering gun to remove an intial hole > in the solder for the adjustment hole. I then enlarged it with a 1/16th drill > bit (by hand). Ideally, a 2mm drill bit could be used. A 5/64th drill bit will > fit through the hole, but it is very tight. Probably not best to drill with > it because that would most likely enlarge the hole. > > I wouldn't open it the same way again, but I'm not sure of the best procedure > that leaves the case and contents undamaged so that it can be reassembled. I > think, perhaps, that I would remove all of the solder that I could as before. > But then, I would make some sort of cut-out for the pins on the bottom and put > it in a pan on the stove and heat it up (hopefully, evenly) until the bottom > could be popped off. The outside case can get pretty hot without damage > because the only contact is the pins and the inside gets pretty hot when > running. The main risk is getting so hot that the plastic spacers on the pins > melt or the pin supports melt. I'm not sure how hot that would be. But, they > must have heated it fairly hot to melt the solder originally, so hopefully > that would work. > > However, here are some pictures of the inside :) which is probably what you > want! > > Top Case 1: [img]http://imgur.com/mvQkJ16[/img] > Top Case 2: [img]http://imgur.com/K7Rmeau[/img] > Bottom Case 1: [img]http://imgur.com/j7tC7QN[/img] > Bottom Case 2: [img]http://imgur.com/TKiofvi[/img] > Outer Oven 1: [img]http://imgur.com/bzYywj7[/img] > Outer Oven 2: [img]http://imgur.com/kKKynzc[/img] > Outer Oven 3: [img]http://imgur.com/xtzFsXD[/img] > Circuit Board: [img]http://imgur.com/PHgnVIm[/img] > > > Mike > > >> Hi Mike, >> Would you be so kindly and post some pictures of the opening process of >> that OCSXO ? >> 73 >> KJ6UHN >> Alex >> On 2/18/2016 7:54 PM, timenut@metachaos.net wrote: >>> Bob, >>> >>> The vendor has said that they did not want the unit back. So... >>> >>> I opened it up. Crudely, I admit. I learned a few things. I was concerned >>> about the outer case heating up too much when I was trying to remove the >>> solder. Turns out that the outer case doesn't touch anything except the pins, >>> so it can get pretty hot without any damage. Unfortunately, I used a bit of >>> brute force to remove the casing after scraping away as much of the solder as >>> I could and after cracking the solder seal with a hammer and screw driver. >>> Even using more heat, I'm not sure of the best way to remove the case. Neither >>> solder wick nor a vacuum desoldering tool is likely to remove all of the >>> solder between the top case and the bottom. >>> >>> Even so, I got the case off. Somewhat bent, even bent the bottom circuit board >>> a bit. I discovered that there is a 2mm hole in the top that allows a variable >>> resistor to be adjusted. You need a pretty long, small screwdriver / adjusting >>> tool to do that, but that is probably for setting the center point. I would >>> try to remove the solder rather than drilling, or drill upside down to prevent >>> solder flakes from falling inside. >>> >>> Also, I found that the -D on my part number appears to correspond to the board >>> revision, which is marked "Rev D". So the -C and -D parts probably have the >>> same specifications. And, on the inside there is a marking "92.0" which I >>> believe would be the set point for this specific crystal. So if I took the >>> crystal out, I would know where to design the set point for a custom unit >>> (currently beyond my skills, but who knows...). >>> >>> From there, I removed the bottom casing. That caused additional damage, some >>> lifted traces and even one very small part (tiny, SMD, who knows?). >>> >>> But, I then soldered wires directly to the board, making patches for the >>> lifted traces. >>> >>> I plugged it in. >>> >>> I turned it on. >>> >>> Success! >>> >>> I gave it 12v which should supply 2A, but it dropped the voltage down to just >>> over 9V. Even so, I got a nice sine wave out at around 4.999790Mhz according >>> to my (uncalibrated) scope and around 800mV (into 50 ohm, DC). That was with >>> nothing attached to the adjustment pin. After some time, the frequency >>> stabilized at 5.000014Mhz and the voltage came back up to 10v. When I attached >>> the adjustment pin to ground, there was no change. When I attached the >>> adjustment pin to Vref (which is at 6.15v), the frequency dropped to >>> 5.000010Mhz. So apparently, these units adjust negatively. But also have a >>> very wide adjustment range of 4Hz (8e-7). I am assuming that the adjustment >>> range is 0..6v. I attached the adjustment pin to +10v and the frequency >>> dropped another 3Hz for a 1.4e-6 adjustment range. >>> >>> I don't expect that this specific unit will be very useful given the damage >>> that I caused opening it up. But, probably there were just bad connections >>> internally, so if I were much more careful in the disassembly, I could >>> probably have fixed it. Something to keep in mind for the next unit. >>> >>> I may be wrong for what the variable resistor does. Turning it made no >>> difference in the frequency. >>> >>> I also suspect, but don't know that the difference from 5Mhz is due to the >>> frequency counter being uncalibrated. It could also because I damaged the unit >>> or just because it is very far off from where it should be. >>> >>> Still, I learned a lot, and well worth the time spent. >>> >>> >>> Mike >>> >>> >>>> Hi >>>> The one advantage you have in testing a used OCXO is you have a pretty good idea of how >>>> you are going to use it. If phase noise does not matter to you … no need to test. I’d always check >>>> that it tunes on freq with reasonable EFC range left over. I’d also make sure that it warms up >>>> properly (oven works) and that it has a reasonable output. What goes on the list past that … >>>> it depends on what you need. >>>> The gear you have will check aging and get it set on frequency fine. It will check it for “wander” >>>> as your lab heats up and cools down. With a GPSDO and a simple phase lock, a DVM may be >>>> all you really need to do most of that. You will not have a proper ADEV, but you will know it works >>>> pretty well (or not ..). >>>> A lightbulb oven / bench / fridge /freezer proces can give you a wide range TC if you need it. >>>> If you do get into phase noise, a sound card system will get you going. For ADEV, the 10811’s >>>> tune far enough that a single mixer system with your 53131 will give you good data. Both >>>> of those will involve some building, but not a lot of money. >>>> There is one thing about the 10811’s: They are not sealed units. They tend to soak up humidity >>>> when stored in most parts of the country. You may want to run them for a month or three >>>> before doing any fancy testing. >>>> Bob >>>>> On Feb 18, 2016, at 7:40 AM, Adrian Godwin <artgodwin@gmail.com> wrote: >>>>> >>>>> I have a small collection of 10811 and similar oscillators here, collected >>>>> from hamfests rather than china (and mostly pre-ebay). >>>>> >>>>> What sort of testing regime would you put them through ? I don't have >>>>> anything as exotic as a timepod but I do have an HP53131A, the Tait Rb >>>>> source, and a KS-24361 set up. And always keen to get hints on the >>>>> acquisition of new toys ! >>>>> >>>>> >>>>> >>>>> On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp <kb8tq@n1k.org> wrote: >>>>> >>>>>> Hi >>>>>> >>>>>> It is *much* better to have an OCXO that you do not need to test to death. >>>>>> There is simply to much testing to do. A modern factory does not test the >>>>>> quality into the product (of any sort) they design in and build it in. The >>>>>> same >>>>>> is true of the normal customer for virtually any component. They make sure >>>>>> the parts come from somebody they can trust and save a lot of testing time. >>>>>> >>>>>> That said, yes, I have a pile of scrap parts sitting in front of me as I >>>>>> type this. >>>>>> It’s a hobby. Time does not count. It lets me play with all sorts of toys >>>>>> doing >>>>>> the testing. I occasionally learn things in the process. Mostly I learn >>>>>> that >>>>>> my hope of a 100% perfect batch is still a dream …. >>>>>> >>>>>> Bob >>>>>> >>>>>> >>>>>> >>>>>>> On Feb 17, 2016, at 9:56 PM, timenut@metachaos.net wrote: >>>>>>> >>>>>>> Bob, >>>>>>> >>>>>>> In this case, I know how it was taken off the board - it wasn't. They >>>>>> just cut >>>>>>> the board around it. I had to remove it myself. Nice thing about that, >>>>>> is that >>>>>>> I got a nice plastic, pre-formed part that fits between the board and the >>>>>>> OCXO, probably as an insulator. >>>>>>> >>>>>>> You are also right about the number of things that you need to test to >>>>>> make >>>>>>> sure that one of these is fully functional. However, this is a "starter" >>>>>> OCXO >>>>>>> for me and I don't yet have the equipment to perform the tests. The best >>>>>> that >>>>>>> I can do is to make sure that, when powered up >>>>>>> >>>>>>> 1. I see something that sort of looks like a sine wave at a reasonable >>>>>>> magnitude. >>>>>>> >>>>>>> 2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz. >>>>>>> >>>>>>> 3. If I apply gnd, or VRef to the adjustment pin I see the frequency >>>>>> change >>>>>>> at least a small amount. >>>>>>> >>>>>>> Without more equipment, there isn't much more that I can do to test. >>>>>> Unless >>>>>>> you have some suggestions? >>>>>>> >>>>>>> >>>>>>> Mike >>>>>>> >>>>>>> >>>>>>>> Hi >>>>>>>> Best guess is these things get taken off the board with either a big >>>>>> torch or a charcoal fire. >>>>>>>> You can ask Mr Google to dig up pictures of the process. Depending on >>>>>> just how quick >>>>>>>> they are, the insides of the OCXO can easily be reflowed. The >>>>>> likelihood of it reflowing and >>>>>>>> cooling back to a reliable joint … not real good. >>>>>>>> Bob >>>>>>>>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7@ermione.com> >>>>>> wrote: >>>>>>>>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut@metachaos.net wrote: >>>>>>>>> >>>>>>>>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After >>>>>> testing it, >>>>>>>>>> it is clear that it is defective. >>>>>>>>>> >>>>>>>>>> 1. It never heats up. >>>>>>>>>> 2. The reference voltage is zero. >>>>>>>>>> 3. Only noise is seen on the output pin. >>>>>>>>> I had the same issue with some of them. It's very likely that the >>>>>> internal >>>>>>>>> solder connections from pins to PCB are broken, at least, the one for >>>>>> power. >>>>>>>>> It happens because the inner oven is heavy and there isn't any thermal >>>>>>>>> insulator (besides air) to keep it from moving. >>>>>>>>> >>>>>>>>> Wheter the crystal has been damaged or not, it's unknown. I had one >>>>>> where the >>>>>>>>> crystal actually fell off from its supports too. >>>>>>>>> >>>>>>>>> I posted a link to photos of the internals, time ago. The link is dead >>>>>> now >>>>>>>>> and I don't think to have the photos anymore but perhaps someone >>>>>> downloaded >>>>>>>>> them. >>>>>>>>> >>>>>>>>> Best regards, >>>>>>>>> Andrea Baldoni >>>>>>>>> _______________________________________________ >>>>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>>>> and follow the instructions there. >>>>>>>> _______________________________________________ >>>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>>> and follow the instructions there. >>>>>>> >>>>>>> -- >>>>>>> Best regards, >>>>>>> Timenut mailto:timenut@metachaos.net >>>>>>> >>>>>>> _______________________________________________ >>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>> and follow the instructions there. >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> > > > --- El software de antivirus Avast ha analizado este correo electrónico en busca de virus. https://www.avast.com/antivirus

I have just about finished trashing this OCXO. I was able to run it outside of its case, and I have repaired the case, but I was unable to reinstall it into the case because I have to patch it on both the top and bottom. I could, perhaps, put it into a larger case and might do that later. For now, I will keep it as a potential future resource. The SC crystal is worth that much - they aren't cheap and nothing wrong with that. Also, just the bottom circuit board has problems, possibly another bad unit could be used for parts. That leaves one final question. The suggestion that the POT adjusts the temperature set point for the crystal sounds very reasonable. It clearly does not significantly affect the frequency. At least, not in the range that would allow for tuning the output frequency. However, the POT is clearly designed to be adjusted AFTER everything is assembled because it is intended to be adjusted through the hole in the case. That assumes some sort of feedback. What feedback? What can it affect on the available five pins that would let you know when the temperature is set correctly? If it is not for setting the temperature, and not for setting the frequency, what is it for? Perhaps output voltage level? I would have to get it working again, but I could test that. Any ideas? Mike

timenut@metachaos.net said: > However, the POT is clearly designed to be adjusted AFTER everything is > assembled because it is intended to be adjusted through the hole in the > case. That assumes some sort of feedback. What feedback? If it adjusts the temperature, the idea is to tune it so that it runs at a flat spot on the temperature vs frequency curve. You don't actually care what the temperature is, just that you set it at the flat spot. You could measure the curve with several data points, then interpolate and set it to the best spot. I'd expect something like that is part of the burn in process. I wonder if they have it automated or if a human has to make each adjustment. -- These are my opinions. I hate spam.

It always helps to know a little about the specific design of the temp control circuit but let's say counter clockwise CCW reduces the internal oven temp. This can be confirmed by letting the temp and frequency stabilize. Using a counter with good resolution monitoring the output frequency, turn the pot CCW several turns and the frequency should slowly decrease a few cycles (typically positive temp coefficient) as the oven cools. Now slowly turn the pot CW about 1/2 turn on each increment watching the frequency slowly increase due to the internal crystal oven slowly getting hotter. Eventually, the frequency will peak and further CW turning of the pot will start to lower the frequency. That's why it called the turn-over temperature. Now set the pot in the middle of two equal frequency points on either side of the frequency peak. Hopefully you will see a broad frequency peak allowing for a little more margin in the oven temperature. All you need to monitor is the output frequency. This process can be a little faster if you have some type of external analog oven temperature indication but it not necessary. Don -----Original Message----- From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of timenut@metachaos.net Sent: Friday, February 19, 2016 9:02 PM To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Subject: Re: [time-nuts] MTI 260-0624-D OCXO I have just about finished trashing this OCXO. I was able to run it outside of its case, and I have repaired the case, but I was unable to reinstall it into the case because I have to patch it on both the top and bottom. I could, perhaps, put it into a larger case and might do that later. For now, I will keep it as a potential future resource. The SC crystal is worth that much - they aren't cheap and nothing wrong with that. Also, just the bottom circuit board has problems, possibly another bad unit could be used for parts. That leaves one final question. The suggestion that the POT adjusts the temperature set point for the crystal sounds very reasonable. It clearly does not significantly affect the frequency. At least, not in the range that would allow for tuning the output frequency. However, the POT is clearly designed to be adjusted AFTER everything is assembled because it is intended to be adjusted through the hole in the case. That assumes some sort of feedback. What feedback? What can it affect on the available five pins that would let you know when the temperature is set correctly? If it is not for setting the temperature, and not for setting the frequency, what is it for? Perhaps output voltage level? I would have to get it working again, but I could test that. Any ideas? Mike _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.