Learned Gentlemen, I personally dislike equipment that uses *wall warts* due to quality concerns One inexpensive way I've powered my Lucent equipment is using used laptop power supplies. They're easily found at HamFests or on ebay.  On Ebay prices very wildly.  If you buy 3 or 4 they can be $5 each shipped. Another source to consider are the Mean Well SRPS at Jameco.  They run from 55 watts on up with a wide range of voltages.  They are have spec sheets.  Some SRPS's on ebay are cheap but their quality....... Regards, Perrier

Hi > On May 2, 2020, at 8:10 PM, Perry Sandeen via time-nuts <time-nuts@lists.febo.com> wrote: > > Learned Gentlemen, > I personally dislike equipment that uses *wall warts* due to quality concerns > One inexpensive way I've powered my Lucent equipment is using used laptop power supplies. They're easily found at HamFests or on ebay. On Ebay prices very wildly. If you buy 3 or 4 they can be $5 each shipped. > Another source to consider are the Mean Well SRPS at Jameco. If you are shopping for Mean Well supplies, TRC https://www.trcelectronics.com/mean-well <https://www.trcelectronics.com/mean-well> is a good place to shop. They are a (if not the) factory direct US distributor for the brand. That should eliminate the risk of getting one labeled Meen Well or Men Well or …. That sort of thing is pretty common on eBay. At least on the stuff I’ve shopped for, their prices are pretty good. They deliver next day on the cheap. Of course that’s probably because they are about 2 hours down the road from here :) Bob > They run from 55 watts on up with a wide range of voltages. They are have spec sheets. Some SRPS's on ebay are cheap but their quality....... > Regards, > Perrier > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

Has anyone found schematics for the Mean Well supplies? I have a couple of 15V 7A ones that will adjust down to 14.1 and I’d like to get them down to the 12-13.8 range. Steve WB0DBS > On May 3, 2020, at 8:43 AM, Bob kb8tq <kb8tq@n1k.org> wrote: > > Hi > > >> On May 2, 2020, at 8:10 PM, Perry Sandeen via time-nuts <time-nuts@lists.febo.com> wrote: >> >> Learned Gentlemen, >> I personally dislike equipment that uses *wall warts* due to quality concerns >> One inexpensive way I've powered my Lucent equipment is using used laptop power supplies. They're easily found at HamFests or on ebay. On Ebay prices very wildly. If you buy 3 or 4 they can be $5 each shipped. >> Another source to consider are the Mean Well SRPS at Jameco. > > If you are shopping for Mean Well supplies, TRC > > https://www.trcelectronics.com/mean-well <https://www.trcelectronics.com/mean-well> > > is a good place to shop. They are a (if not the) factory direct US distributor for the > brand. That should eliminate the risk of getting one labeled Meen Well or Men Well or …. > That sort of thing is pretty common on eBay. > > At least on the stuff I’ve shopped for, their prices are pretty good. They deliver next > day on the cheap. Of course that’s probably because they are about 2 hours down the > road from here :) > > Bob > >> They run from 55 watts on up with a wide range of voltages. They are have spec sheets. Some SRPS's on ebay are cheap but their quality....... >> Regards, >> Perrier >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

Hi If you want to do it and get full output, the change probably involves nasty things like swapping out inductors …. Likely cheaper to just spend the $16 and buy a brand new one at the right voltage. https://www.trcelectronics.com/View/Mean-Well/LRS-100-12.shtml <https://www.trcelectronics.com/View/Mean-Well/LRS-100-12.shtml> Given the risks of getting a mod “almost right”, it’s probably worth the piece of mind with a new one as well. Bob > On May 3, 2020, at 9:53 AM, Steve - Home <steve-krull@cox.net> wrote: > > Has anyone found schematics for the Mean Well supplies? I have a couple of 15V 7A ones that will adjust down to 14.1 and I’d like to get them down to the 12-13.8 range. > > Steve > WB0DBS > > > >> On May 3, 2020, at 8:43 AM, Bob kb8tq <kb8tq@n1k.org> wrote: >> >> Hi >> >> >>> On May 2, 2020, at 8:10 PM, Perry Sandeen via time-nuts <time-nuts@lists.febo.com> wrote: >>> >>> Learned Gentlemen, >>> I personally dislike equipment that uses *wall warts* due to quality concerns >>> One inexpensive way I've powered my Lucent equipment is using used laptop power supplies. They're easily found at HamFests or on ebay. On Ebay prices very wildly. If you buy 3 or 4 they can be $5 each shipped. >>> Another source to consider are the Mean Well SRPS at Jameco. >> >> If you are shopping for Mean Well supplies, TRC >> >> https://www.trcelectronics.com/mean-well <https://www.trcelectronics.com/mean-well> >> >> is a good place to shop. They are a (if not the) factory direct US distributor for the >> brand. That should eliminate the risk of getting one labeled Meen Well or Men Well or …. >> That sort of thing is pretty common on eBay. >> >> At least on the stuff I’ve shopped for, their prices are pretty good. They deliver next >> day on the cheap. Of course that’s probably because they are about 2 hours down the >> road from here :) >> >> Bob >> >>> They run from 55 watts on up with a wide range of voltages. They are have spec sheets. Some SRPS's on ebay are cheap but their quality....... >>> Regards, >>> Perrier >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

Steve, you shouldn't need a schematic. Look for a resistor between the output + line and the pot that adjusts the voltage. Determine the value and add a shunt resistor across it that is maybe 10x the value determined. See if that drops it down enough. Adjust the shunt up or down to get the range you want. Also note that if this is a linear supply setting it for a lower output voltage range will increase dissipation at full load and possibly require better / forced air cooling. Bob L. > Sent: Sunday, May 03, 2020 at 9:53 AM > From: "Steve - Home" <steve-krull@cox.net> > To: "Discussion of precise time and frequency measurement" <time-nuts@lists.febo.com> > Subject: Re: [time-nuts] Power Supplies > > Has anyone found schematics for the Mean Well supplies? I have a couple of 15V 7A ones that will adjust down to 14.1 and I’d like to get them down to the 12-13.8 range. > > Steve > WB0DBS

Hi Bob, Main reason was I already have a few 15V ones and would like to reuse them. I have a gut feeling there’s not a major difference between the 12V and 15V models. I may get one of the 12V ones and open it up and do a comparison. I thought maybe someone had been down that path before. Steve WB0DBS > On May 3, 2020, at 9:15 AM, Bob kb8tq <kb8tq@n1k.org> wrote: > > Hi > > If you want to do it and get full output, the change probably involves nasty things > like swapping out inductors …. Likely cheaper to just spend the $16 and buy > a brand new one at the right voltage. > > https://www.trcelectronics.com/View/Mean-Well/LRS-100-12.shtml <https://www.trcelectronics.com/View/Mean-Well/LRS-100-12.shtml> > > Given the risks of getting a mod “almost right”, it’s probably worth the piece of mind > with a new one as well. > > Bob > >> On May 3, 2020, at 9:53 AM, Steve - Home <steve-krull@cox.net> wrote: >> >> Has anyone found schematics for the Mean Well supplies? I have a couple of 15V 7A ones that will adjust down to 14.1 and I’d like to get them down to the 12-13.8 range. >> >> Steve >> WB0DBS >> >> >> >>>> On May 3, 2020, at 8:43 AM, Bob kb8tq <kb8tq@n1k.org> wrote: >>> >>> Hi >>> >>> >>>> On May 2, 2020, at 8:10 PM, Perry Sandeen via time-nuts <time-nuts@lists.febo.com> wrote: >>>> >>>> Learned Gentlemen, >>>> I personally dislike equipment that uses *wall warts* due to quality concerns >>>> One inexpensive way I've powered my Lucent equipment is using used laptop power supplies. They're easily found at HamFests or on ebay. On Ebay prices very wildly. If you buy 3 or 4 they can be $5 each shipped. >>>> Another source to consider are the Mean Well SRPS at Jameco. >>> >>> If you are shopping for Mean Well supplies, TRC >>> >>> https://www.trcelectronics.com/mean-well <https://www.trcelectronics.com/mean-well> >>> >>> is a good place to shop. They are a (if not the) factory direct US distributor for the >>> brand. That should eliminate the risk of getting one labeled Meen Well or Men Well or …. >>> That sort of thing is pretty common on eBay. >>> >>> At least on the stuff I’ve shopped for, their prices are pretty good. They deliver next >>> day on the cheap. Of course that’s probably because they are about 2 hours down the >>> road from here :) >>> >>> Bob >>> >>>> They run from 55 watts on up with a wide range of voltages. They are have spec sheets. Some SRPS's on ebay are cheap but their quality....... >>>> Regards, >>>> Perrier >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>>> and follow the instructions there. >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

Thanks Bob, I’ll have a look at that. Steve WB0DBS > On May 3, 2020, at 9:23 AM, Robert LaJeunesse <lajeunesse@mail.com> wrote: > > Steve, you shouldn't need a schematic. Look for a resistor between the output + line and the pot that adjusts the voltage. Determine the value and add a shunt resistor across it that is maybe 10x the value determined. See if that drops it down enough. Adjust the shunt up or down to get the range you want. Also note that if this is a linear supply setting it for a lower output voltage range will increase dissipation at full load and possibly require better / forced air cooling. > > Bob L. > >> Sent: Sunday, May 03, 2020 at 9:53 AM >> From: "Steve - Home" <steve-krull@cox.net> >> To: "Discussion of precise time and frequency measurement" <time-nuts@lists.febo.com> >> Subject: Re: [time-nuts] Power Supplies >> >> Has anyone found schematics for the Mean Well supplies? I have a couple of 15V 7A ones that will adjust down to 14.1 and I’d like to get them down to the 12-13.8 range. >> >> Steve >> WB0DBS > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

Hi Unfortunately, there usually *is* a difference on each of these supplies. They “fine tune” them for one specific voltage. Since the magnetics are often done in house, there’s not much of a way to figure out everything that they have done. The risk with any switcher is that they can (and sometimes do) fail in a dramatic fashion. That may involve taking out the gear they are attached to when they fail. I had that happen with one about two years ago. The device cost $120 to replace. What it killed was $400 and could have been up in the $10,000 range. Obviously this was not on the bench in the basement ….. Bob > On May 3, 2020, at 10:26 AM, Steve - Home <steve-krull@cox.net> wrote: > > Hi Bob, > > Main reason was I already have a few 15V ones and would like to reuse them. I have a gut feeling there’s not a major difference between the 12V and 15V models. I may get one of the 12V ones and open it up and do a comparison. I thought maybe someone had been down that path before. > > Steve > WB0DBS > > > >> On May 3, 2020, at 9:15 AM, Bob kb8tq <kb8tq@n1k.org> wrote: >> >> Hi >> >> If you want to do it and get full output, the change probably involves nasty things >> like swapping out inductors …. Likely cheaper to just spend the $16 and buy >> a brand new one at the right voltage. >> >> https://www.trcelectronics.com/View/Mean-Well/LRS-100-12.shtml <https://www.trcelectronics.com/View/Mean-Well/LRS-100-12.shtml> >> >> Given the risks of getting a mod “almost right”, it’s probably worth the piece of mind >> with a new one as well. >> >> Bob >> >>> On May 3, 2020, at 9:53 AM, Steve - Home <steve-krull@cox.net> wrote: >>> >>> Has anyone found schematics for the Mean Well supplies? I have a couple of 15V 7A ones that will adjust down to 14.1 and I’d like to get them down to the 12-13.8 range. >>> >>> Steve >>> WB0DBS >>> >>> >>> >>>>> On May 3, 2020, at 8:43 AM, Bob kb8tq <kb8tq@n1k.org> wrote: >>>> >>>> Hi >>>> >>>> >>>>> On May 2, 2020, at 8:10 PM, Perry Sandeen via time-nuts <time-nuts@lists.febo.com> wrote: >>>>> >>>>> Learned Gentlemen, >>>>> I personally dislike equipment that uses *wall warts* due to quality concerns >>>>> One inexpensive way I've powered my Lucent equipment is using used laptop power supplies. They're easily found at HamFests or on ebay. On Ebay prices very wildly. If you buy 3 or 4 they can be $5 each shipped. >>>>> Another source to consider are the Mean Well SRPS at Jameco. >>>> >>>> If you are shopping for Mean Well supplies, TRC >>>> >>>> https://www.trcelectronics.com/mean-well <https://www.trcelectronics.com/mean-well> >>>> >>>> is a good place to shop. They are a (if not the) factory direct US distributor for the >>>> brand. That should eliminate the risk of getting one labeled Meen Well or Men Well or …. >>>> That sort of thing is pretty common on eBay. >>>> >>>> At least on the stuff I’ve shopped for, their prices are pretty good. They deliver next >>>> day on the cheap. Of course that’s probably because they are about 2 hours down the >>>> road from here :) >>>> >>>> Bob >>>> >>>>> They run from 55 watts on up with a wide range of voltages. They are have spec sheets. Some SRPS's on ebay are cheap but their quality....... >>>>> Regards, >>>>> Perrier >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>>>> and follow the instructions there. >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>>> and follow the instructions there. >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

I bit the bullet and ordered a pair of 12V supplies. I’ll see what I can suss out for differences when I get them side by side on the bench. Steve WB0DBS > On May 3, 2020, at 9:39 AM, Bob kb8tq <kb8tq@n1k.org> wrote: > > Hi > > Unfortunately, there usually *is* a difference on each of these supplies. > They “fine tune” them for one specific voltage. Since the magnetics are > often done in house, there’s not much of a way to figure out everything > that they have done. > > The risk with any switcher is that they can (and sometimes do) fail in a > dramatic fashion. That may involve taking out the gear they are attached > to when they fail. > > I had that happen with one about two years ago. The device cost $120 to > replace. What it killed was $400 and could have been up in the $10,000 range. > Obviously this was not on the bench in the basement ….. > > Bob > >> On May 3, 2020, at 10:26 AM, Steve - Home <steve-krull@cox.net> wrote: >> >> Hi Bob, >> >> Main reason was I already have a few 15V ones and would like to reuse them. I have a gut feeling there’s not a major difference between the 12V and 15V models. I may get one of the 12V ones and open it up and do a comparison. I thought maybe someone had been down that path before. >> >> Steve >> WB0DBS >> >> >> >>>> On May 3, 2020, at 9:15 AM, Bob kb8tq <kb8tq@n1k.org> wrote: >>> >>> Hi >>> >>> If you want to do it and get full output, the change probably involves nasty things >>> like swapping out inductors …. Likely cheaper to just spend the $16 and buy >>> a brand new one at the right voltage. >>> >>> https://www.trcelectronics.com/View/Mean-Well/LRS-100-12.shtml <https://www.trcelectronics.com/View/Mean-Well/LRS-100-12.shtml> >>> >>> Given the risks of getting a mod “almost right”, it’s probably worth the piece of mind >>> with a new one as well. >>> >>> Bob >>> >>>> On May 3, 2020, at 9:53 AM, Steve - Home <steve-krull@cox.net> wrote: >>>> >>>> Has anyone found schematics for the Mean Well supplies? I have a couple of 15V 7A ones that will adjust down to 14.1 and I’d like to get them down to the 12-13.8 range. >>>> >>>> Steve >>>> WB0DBS >>>> >>>> >>>> >>>>>> On May 3, 2020, at 8:43 AM, Bob kb8tq <kb8tq@n1k.org> wrote: >>>>> >>>>> Hi >>>>> >>>>> >>>>>> On May 2, 2020, at 8:10 PM, Perry Sandeen via time-nuts <time-nuts@lists.febo.com> wrote: >>>>>> >>>>>> Learned Gentlemen, >>>>>> I personally dislike equipment that uses *wall warts* due to quality concerns >>>>>> One inexpensive way I've powered my Lucent equipment is using used laptop power supplies. They're easily found at HamFests or on ebay. On Ebay prices very wildly. If you buy 3 or 4 they can be $5 each shipped. >>>>>> Another source to consider are the Mean Well SRPS at Jameco. >>>>> >>>>> If you are shopping for Mean Well supplies, TRC >>>>> >>>>> https://www.trcelectronics.com/mean-well <https://www.trcelectronics.com/mean-well> >>>>> >>>>> is a good place to shop. They are a (if not the) factory direct US distributor for the >>>>> brand. That should eliminate the risk of getting one labeled Meen Well or Men Well or …. >>>>> That sort of thing is pretty common on eBay. >>>>> >>>>> At least on the stuff I’ve shopped for, their prices are pretty good. They deliver next >>>>> day on the cheap. Of course that’s probably because they are about 2 hours down the >>>>> road from here :) >>>>> >>>>> Bob >>>>> >>>>>> They run from 55 watts on up with a wide range of voltages. They are have spec sheets. Some SRPS's on ebay are cheap but their quality....... >>>>>> Regards, >>>>>> Perrier >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>>>>> and follow the instructions there. >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>>>> and follow the instructions there. >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>>> and follow the instructions there. >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

If you have a supply with something north of 15V, and you'd like to make 12V battery type voltage, it's easy to add an external solution with a low dropout three-terminal regulator to take it down a bit and still get good regulation. Look at LT1085 family, for example. Ed