Date set for next Sphere Stuff Day/Radio Amateur Swap Meet
About opening cases, I opened one, repaired the oscillator and sealed it
back up (sort of).
In the early 2000's I had a 10 MHz OCXO that I used as the main
reference for my 10 GHz ham rover rig. It was really doing the job for
me until I accidentally hooked it up to DC power backwards and killed
it. I was hoping I could find some way to fix it. The oscillator was one
of the larger metal packages about 3" long by about 2" square. Here's
how I opened it.
Earlier I had tried to unsolder a smaller oscillator (about the size of
the MTI 260) with a torch. It's hard to heat the two sections fast with
a torch to melt the solder and find a way to grab them both ad pull
apart while the solder is melted. On that attempt, I eventually got it
apart but desoldered some internal circuit board components in the process.
For this other broken oscillator that I liked, I decided it might be
better to mechanically cut it apart. I assumed that the bottom piece
probably had a lip about 1/4 to 3/8 " long that fit tightly inside of
the top case and that lip was soldered to join the two pieces. I wanted
to cut off the top case right where the solder joint ended. I first
drilled a small test hole into the side of the outer case about where I
guessed the solder joint ended inside, Ideally just through the outer
case. Then with a small Dremel bit I enlarged this hole to to figure out
exactly where the solder seam ended. Then I carefully cut the main case
around the end of the solder joint. Ideally I cut just a little below
the end of the inner lip to keep a slight aligning surface for putting
it back together later.
For the cutting, I had a milling machine that I used, But once you know
where you want to cut, I think careful hack sawing or a Dremel ceramic
disk could have done the job. With only a little bit of solder now
holding the cut top case on, a little prying removed it.
[Another option might be to cut vertical slits in the outer case just
either side of the round corners (8 cuts) and just as long as the
internal soldered flange. The object is to turn the bottom sides of the
outer case into tabs that can be bent out. Driving a knife or chisel
into the solderd seam will hopefully pry the flaps outward. Getting the
corners loose would probably be the hard part. Cutting them as in my
other method might be the easiest. With this method, after opening, I
think you could then cut or melt of excess solder.off the main case and
base, straighten the main case sides and get a good strong seam on
reassembly.]
The blown oscillator I cut open had smt components inside. I replaced
all the active devices and electrolytic caps I found in the circuit and
checked to find that it worked again. (Yay!) I then was able to solder
the top case back on the base. Not quite as strong as the original with
just a narrow solder bead holding it, but working good as new.
Of course, if the oscillator's metal case is providing a hermetic seal,
you loose that, but most aren't, anyway.
So I just thought I'd mention this other mechanical attack method. I
think unsoldering the whole solder seal in one go and pulling it apart
without damaging the internals is a pretty difficult task.
-Rex
On 2/19/2016 9:09 AM, 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
If this is a double oven, there are two oven circuits and two oven controllers.
Both would have a set point and both would be adjusted somehow. The pot
may be the adjustment on the outer oven. Get things all set up and packaged,
then adjust the outer oven to make things do what the should do.
Bob
On Feb 19, 2016, at 7:29 PM, EB4APL eb4apl@gmail.com wrote:
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
-
I see something that sort of looks like a sine wave at a reasonable
magnitude. -
My 2465B CT frequency counter thinks that it is somewhere near 5Mhz.
-
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.
- It never heats up.
- The reference voltage is zero.
- 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
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Timenut mailto:timenut@metachaos.net
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Bob,
I still have a problem with the various theories. Again, how is it measured?
If you have a production line, you don't want a "tweak" that requires hours or
days to determine.
As far as setting the crystal set point (presumably the inner over set point),
that makes even less sense. Consider that they clearly knew the turn over
point of the crystal BEFORE it was packaged. They wrote it on the sticker inside.
So, they would have no need to adjust the inner oven. That could easily have
been done on the bench during assembly. It could also be done via a selection
from a standardized set of components. That temperature is "sort of" critical.
The curve is very flat, to it could be a little off. Since they knew the
crystal turn over point in advance, there wouldn't be any need to "hunt" for
it by an elaborate procedure after assembly.
However, the temperature of the outer oven is much less critical and I would
suspect is simply set by the choice of components. And, if it needed tweaking
then it could also have been done on the bench. Since they would know the
thermal transfer characteristics, I suppose that they could measure the outer
case's temperature to deduce the correct temperature of the outer oven. But,
again, that doesn't make sense from a production standpoint. It would simply
take too long.
Perhaps, they would be willing to eat the time needed for that type of
adjustment, but it doesn't seem likely. All they would need to do would be to
add some monitoring circuits that they could access. I've seen that type of
thing a lot. It would be cheaper to add a few circuits for a quick adjustment
than it would be to spend the time on the adjustment. People's time is worth a
lot more than a few components.
On the other hand, tweaking the output voltage is something that is quickly
measured as part of testing. Put it in a jig, make a quick check for
functionality, tweak the output voltage and you are done. Or, perhaps it
adjusts the duty cycle, the bias point or some other characteristic of the
output signal. Perhaps it adjusts the reference voltage. I think I showed that
it doesn't make a large change in the frequency. But, it doesn't make sense
for it to make a small change (although I would be unable to measure a small
change).
I think that there are a lot of unexplored possibilities, but I definitely am
not convinced that it sets either the inner or outer oven temperature. There
are simply better ways to do that in production.
I really, really want to know, though! I am going to try to repair mine one
more time and see what I can measure. I didn't try very hard the first time,
but I think its worth doing. If I can get it repaired again (I have to fix
some traces, especially for the ground pin) it will probably take a couple of
days. I have the parts to fix my fan circuit in my oscilloscope and I will do
that first. And possibly tweak the power supply capacitors to reduce noise.
Mike
If this is a double oven, there are two oven circuits and two oven controllers.
Both would have a set point and both would be adjusted somehow. The pot
may be the adjustment on the outer oven. Get things all set up and packaged,
then adjust the outer oven to make things do what the should do.
Hi
Anything electrical (duty cycle/ harmonics / output level / etc)
is designed in on a modern part done in high volume.
The only candidates for a pot on top of the oven are:
Inner oven temperature
Outer oven temperature
EFC
You have already ruled out EFC (it would be a coarse set so
visible on a normal counter).
That leaves inner oven and outer oven.
Why inner oven - to adjust for the data from your temperature run. The parts
are at best coarse set based on crystal temperature.
Why outer oven - same as above or to set for inner / outer separation
and clearance after the thermal stabilization in the sealed can.
If there is no apparent change in frequency (and from the location of
the pot) that suggests the outer oven. Regardless of which oven is being set, the
adjustment is likely a “move it 1.25 turns" sort of thing. You then
re-run the temperature test to see if it is in spec yet.
Bob
On Feb 20, 2016, at 2:56 PM, timenut@metachaos.net wrote:
Bob,
I still have a problem with the various theories. Again, how is it measured?
If you have a production line, you don't want a "tweak" that requires hours or
days to determine.
As far as setting the crystal set point (presumably the inner over set point),
that makes even less sense. Consider that they clearly knew the turn over
point of the crystal BEFORE it was packaged. They wrote it on the sticker inside.
So, they would have no need to adjust the inner oven. That could easily have
been done on the bench during assembly. It could also be done via a selection
from a standardized set of components. That temperature is "sort of" critical.
The curve is very flat, to it could be a little off. Since they knew the
crystal turn over point in advance, there wouldn't be any need to "hunt" for
it by an elaborate procedure after assembly.
However, the temperature of the outer oven is much less critical and I would
suspect is simply set by the choice of components. And, if it needed tweaking
then it could also have been done on the bench. Since they would know the
thermal transfer characteristics, I suppose that they could measure the outer
case's temperature to deduce the correct temperature of the outer oven. But,
again, that doesn't make sense from a production standpoint. It would simply
take too long.
Perhaps, they would be willing to eat the time needed for that type of
adjustment, but it doesn't seem likely. All they would need to do would be to
add some monitoring circuits that they could access. I've seen that type of
thing a lot. It would be cheaper to add a few circuits for a quick adjustment
than it would be to spend the time on the adjustment. People's time is worth a
lot more than a few components.
On the other hand, tweaking the output voltage is something that is quickly
measured as part of testing. Put it in a jig, make a quick check for
functionality, tweak the output voltage and you are done. Or, perhaps it
adjusts the duty cycle, the bias point or some other characteristic of the
output signal. Perhaps it adjusts the reference voltage. I think I showed that
it doesn't make a large change in the frequency. But, it doesn't make sense
for it to make a small change (although I would be unable to measure a small
change).
I think that there are a lot of unexplored possibilities, but I definitely am
not convinced that it sets either the inner or outer oven temperature. There
are simply better ways to do that in production.
I really, really want to know, though! I am going to try to repair mine one
more time and see what I can measure. I didn't try very hard the first time,
but I think its worth doing. If I can get it repaired again (I have to fix
some traces, especially for the ground pin) it will probably take a couple of
days. I have the parts to fix my fan circuit in my oscilloscope and I will do
that first. And possibly tweak the power supply capacitors to reduce noise.
Mike
If this is a double oven, there are two oven circuits and two oven controllers.
Both would have a set point and both would be adjusted somehow. The pot
may be the adjustment on the outer oven. Get things all set up and packaged,
then adjust the outer oven to make things do what the should do.
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and follow the instructions there.
Mike,
the most likely use of that mysterious pot is for final frequency
adjustment.
You might just not have measured with sufficient resolution.
I agree with you that the oven temperature theory makes not overly much
sense.
If you want to know for sure, you may check what the pot is connected to.
Adrian
timenut@metachaos.net schrieb:
Bob,
I still have a problem with the various theories. Again, how is it measured?
If you have a production line, you don't want a "tweak" that requires hours or
days to determine.
As far as setting the crystal set point (presumably the inner over set point),
that makes even less sense. Consider that they clearly knew the turn over
point of the crystal BEFORE it was packaged. They wrote it on the sticker inside.
So, they would have no need to adjust the inner oven. That could easily have
been done on the bench during assembly. It could also be done via a selection
from a standardized set of components. That temperature is "sort of" critical.
The curve is very flat, to it could be a little off. Since they knew the
crystal turn over point in advance, there wouldn't be any need to "hunt" for
it by an elaborate procedure after assembly.
However, the temperature of the outer oven is much less critical and I would
suspect is simply set by the choice of components. And, if it needed tweaking
then it could also have been done on the bench. Since they would know the
thermal transfer characteristics, I suppose that they could measure the outer
case's temperature to deduce the correct temperature of the outer oven. But,
again, that doesn't make sense from a production standpoint. It would simply
take too long.
Perhaps, they would be willing to eat the time needed for that type of
adjustment, but it doesn't seem likely. All they would need to do would be to
add some monitoring circuits that they could access. I've seen that type of
thing a lot. It would be cheaper to add a few circuits for a quick adjustment
than it would be to spend the time on the adjustment. People's time is worth a
lot more than a few components.
On the other hand, tweaking the output voltage is something that is quickly
measured as part of testing. Put it in a jig, make a quick check for
functionality, tweak the output voltage and you are done. Or, perhaps it
adjusts the duty cycle, the bias point or some other characteristic of the
output signal. Perhaps it adjusts the reference voltage. I think I showed that
it doesn't make a large change in the frequency. But, it doesn't make sense
for it to make a small change (although I would be unable to measure a small
change).
I think that there are a lot of unexplored possibilities, but I definitely am
not convinced that it sets either the inner or outer oven temperature. There
are simply better ways to do that in production.
I really, really want to know, though! I am going to try to repair mine one
more time and see what I can measure. I didn't try very hard the first time,
but I think its worth doing. If I can get it repaired again (I have to fix
some traces, especially for the ground pin) it will probably take a couple of
days. I have the parts to fix my fan circuit in my oscilloscope and I will do
that first. And possibly tweak the power supply capacitors to reduce noise.
Mike
If this is a double oven, there are two oven circuits and two oven controllers.
Both would have a set point and both would be adjusted somehow. The pot
may be the adjustment on the outer oven. Get things all set up and packaged,
then adjust the outer oven to make things do what the should do.
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and follow the instructions there.
On Sat, 20 Feb 2016 14:56:47 -0500, you wrote:
I think that there are a lot of unexplored possibilities, but I definitely am
not convinced that it sets either the inner or outer oven temperature. There
are simply better ways to do that in production.
Hi Mike,
On the two that I tested, it appeared to adjust the temperature of
both of the ovens.
One was a 5 MHz 260-0545-B. The outer oven was at 78.2 degC and at
least around that point the temp changed at about 1 degC per turn. The
EFC adjustment on this one was not quite enough to bring the frequency
to exactly 5 MHz, but the oven temp did look to be close to correct.
The other was a 16.384 MHz 260-0546-G which was unused old stock, but
had overall poor stability. It turned out that the oven temp on it was
1-3/8 turns from the turnover point, but when or how that happened I
don't know.
It would be interesting to hear from somebody who knows how this type
of thing is actually adjusted in production.
Angus.
If this is a double oven, there are two oven circuits and two oven controllers.
Both would have a set point and both would be adjusted somehow. The pot
may be the adjustment on the outer oven. Get things all set up and packaged,
then adjust the outer oven to make things do what the should do.
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I got the replacement MTI 260-0624-D OCXO today.
It rattles!
I didn't even bother trying to power it up. Not much point. I have not taken
it apart, but have notified the seller. I may disassemble this one as well,
depending on what the seller says.
Mike
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
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Timenut mailto:timenut@metachaos.net
Hi
Where (what continent) was the seller located?
Bob
On Mar 5, 2016, at 4:45 PM, timenut@metachaos.net wrote:
I got the replacement MTI 260-0624-D OCXO today.
It rattles!
I didn't even bother trying to power it up. Not much point. I have not taken
it apart, but have notified the seller. I may disassemble this one as well,
depending on what the seller says.
Mike
I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After testing it,
it is clear that it is defective.
- It never heats up.
- The reference voltage is zero.
- 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
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and follow the instructions there.
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Best regards,
Timenut mailto:timenut@metachaos.net
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Hi,
On 03/05/2016 10:45 PM, timenut@metachaos.net wrote:
I got the replacement MTI 260-0624-D OCXO today.
It rattles!
I've seen that on one oscillator. I did a RMA and complained about the
maracas mode, which I had demonstrated to the rep. When it arrived they
wondered what that mean and the rep just smiled and ask them to pick it
up... and it rattle. Turns out that the way they soldered their ovens,
drops of solder could form and get loose, so they changed the process.
Unfortunatly, it is also the failure mode of rough shipping/handling for
some oscillators.
Cheers,
Magnus
I didn't even bother trying to power it up. Not much point. I have not taken
it apart, but have notified the seller. I may disassemble this one as well,
depending on what the seller says.
Mike
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
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and follow the instructions there.
Magnus,
In this case, the rattle is not of light weight pieces, but of a heavy object.
So, I am guessing that the outer oven broke off somehow. Won't really know
until and unless I open it up. The vendor probably won't want it back, but
they might, so I won't touch it until I hear from them.
Mike
Hi,
On 03/05/2016 10:45 PM, timenut@metachaos.net wrote:
I got the replacement MTI 260-0624-D OCXO today.
It rattles!
I've seen that on one oscillator. I did a RMA and complained about the
maracas mode, which I had demonstrated to the rep. When it arrived they
wondered what that mean and the rep just smiled and ask them to pick it
up... and it rattle. Turns out that the way they soldered their ovens,
drops of solder could form and get loose, so they changed the process.
Unfortunatly, it is also the failure mode of rough shipping/handling for
some oscillators.
Cheers,
Magnus
I didn't even bother trying to power it up. Not much point. I have not taken
it apart, but have notified the seller. I may disassemble this one as well,
depending on what the seller says.
Mike
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.
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