Gamma Research Very Small Switching Power Supply
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Just got my October issue of CQ and saw a review of this very small power
supply made by Gamma Research, model HPS-1a. It is 3.37 X 1.55 X 5.25 inches, rated at 13.8 VDC, 22 amps at 25% duty cycle and 5 amps continuous, and weighing only 1.25 lbs. If you do not get CQ, then the company's web site (www.gammaresearch.net) provides information. Has anyone tried this with a K2/100 rig? 73, Henry - K4TMC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Gamma Research Very Small Switching Power Supply
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[hidden email] wrote:
> Just got my October issue of CQ and saw a review of this very small power > supply made by Gamma Research, model HPS-1a. It is 3.37 X 1.55 X 5.25 inches, > rated at 13.8 VDC, 22 amps at 25% duty cycle and 5 amps continuous, and weighing > only 1.25 lbs. If you do not get CQ, then the company's web site > (www.gammaresearch.net) provides information. > > Has anyone tried this with a K2/100 rig? > > 73, > Henry - K4TMC > _______________________________________________ > use daily for a FT-857D for SSB and CW which is made by MFJ. It is the MFJ-4125 which is rated at 25 Amps all the time and it SAYS "no noise on all Ham bands", and it sells for $100.00. Your power supply doesn't even mention power supply noies. 73 Karl K5DI _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Gamma Research Very Small Switching Power Supply
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Leigh L. Klotz Jr wrote:
> With 5 farads of filtering it's a probably a bit quieter than the MFJ. The Q of a 5 Farad capacitor is not good. It will carry the peak current from a SSB transmitter but it will not control RF noise. This comes from the high frequency chopping of the input 120 Volts. MFJ has some inductors and low value caps in their power supply to control RF noise. A 5 Farad cap is not cheap. I guess that is why it is more expensive. 73 Karl K5DI > > Karl Larsen wrote: >> Hi Henry, you can buy a power supply which is more powerful and I >> use daily for a FT-857D for SSB and CW which is made by MFJ. It is >> the MFJ-4125 which is rated at 25 Amps all the time and it SAYS "no >> noise on all Ham bands", and it sells for $100.00. >> >> Your power supply doesn't even mention power supply noies. >> >> > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Greeting all,
I have a mail into elecraft, but thought I'd throw this out to the list. I took my KX-1 out camping a few weeks ago, where it was working fine. I finally unpacked it yesterday, and much to my dismay, it seems to be dead. Here's what I discovered: The LED works fine, so it's got power There is no sound on the headphones, and the freq display does not light up. Examining the batteries that were in it, it look like all of them are swollen. Any suggestion on where to begin troubleshooting? Thanks, Tod ---- Tod Glenn N7WD NAQCC #1283 SKCC #1444 FISTS #12134 ARCI #12420 [hidden email] _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Tod Glenn wrote:
> Greeting all, > > I have a mail into elecraft, but thought I'd throw this out to the list. > > I took my KX-1 out camping a few weeks ago, where it was working > fine. I finally unpacked it yesterday, and much to my dismay, it > seems to be dead. > > Here's what I discovered: > > The LED works fine, so it's got power > > There is no sound on the headphones, and the freq display does not > light up. > > Examining the batteries that were in it, it look like all of them are > swollen. > > Any suggestion on where to begin troubleshooting? batteries and then tell us what it does :-) 73 Karl K5DI > > Thanks, Tod > ---- > Tod Glenn > N7WD > NAQCC #1283 > SKCC #1444 > FISTS #12134 > ARCI #12420 > [hidden email] > > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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On Oct 1, 2006, at 9:29 AM, Karl Larsen wrote: > Tod Glenn wrote: >> Greeting all, >> >> I have a mail into elecraft, but thought I'd throw this out to the >> list. >> >> I took my KX-1 out camping a few weeks ago, where it was working >> fine. I finally unpacked it yesterday, and much to my dismay, it >> seems to be dead. >> >> Here's what I discovered: >> >> The LED works fine, so it's got power >> >> There is no sound on the headphones, and the freq display does not >> light up. >> >> Examining the batteries that were in it, it look like all of them >> are swollen. >> >> Any suggestion on where to begin troubleshooting? > Yes Tod, remove and throw away the swollen batteries. Get new > batteries and then tell us what it does :-) Already done. I'm running it off my 13.8v Astron. same problem. ---- Tod Glenn N7WD NAQCC #1283 SKCC #1444 FISTS #12134 ARCI #12420 [hidden email] _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Tod, look for a short in the +12 circuit to ground. The swollen batteries
suggests they were feeding lots of current into a dead short for a long time. Open the unit and do the resistance checks at the top right column on page 54 of your manual. If those checks disclose a short, follow the PCB traces back to the power switch. You may find that one carrying +12 has burned open from the heat of the batteries. After you repair the short, a burned trace can be repaired by cleaning the ends on opposite sides of the break and soldering a short thin wire across the gap. Often batteries cannot supply enough current to actually burn a trace open, but an external supply can. Do the resistance checks to see if the +12 V line is shorted before leaving power applied! There are additional troubleshooting hints in Appendix E1 of your manual. The first section deals with the symptoms you describe. If there's no short on the +12V line, do the voltage checks on page E5 and E6 to see where power is missing. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Gamma Research Very Small Switching Power Supply
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In reply to this post by k4tmc
Good point Karl! I don't have an MFJ to compare but I will bring it
along to AmTech day or Pacificon to test. It fits in my front pocket. 73, Leigh/WA5ZNU On Sun, 1 Oct 2006 4:39 am, Karl Larsen wrote: > Leigh L. Klotz Jr wrote: >> With 5 farads of filtering it's a probably a bit quieter than the MFJ. > The Q of a 5 Farad capacitor is not good. It will carry the peak > current from a SSB transmitter but it will not control RF noise. This > comes from the high frequency chopping of the input 120 Volts. MFJ has > some inductors and low value caps in their power supply to control RF > noise. > > A 5 Farad cap is not cheap. I guess that is why it is more > expensive. > > 73 Karl K5DI > >> >> Karl Larsen wrote: >>> Hi Henry, you can buy a power supply which is more powerful and I >>> use daily for a FT-857D for SSB and CW which is made by MFJ. It is >>> the MFJ-4125 which is rated at 25 Amps all the time and it SAYS "no >>> noise on all Ham bands", and it sells for $100.00. >>> >>> Your power supply doesn't even mention power supply noies. >>> >>> >> >> > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft Help: > http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Gamma Research Very Small Switching Power Supply
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I just did a noise test and found either no noise or almost no noise on
all bands. I hooked the Gamma Research supply to my K2, along with the internal battery. I disconnected all other connections (RS232, key, antenna). I set the mode to USB and the Preamp=ON and spot checked the bands from 160 to 10m. For each band, I turned the power supply off and on, and then the power supply was on, switched off the internal battery. This kept the rig from ever being off. When the power supply is off, the rig is running off the 5 paralleled 25 F capacitors and the internal battery. I also did the same test but additionally removed the DC coax plug from the K2 power jack. I noticed a slight increase in noise floor on 14.060, but I could not reliably reproduce it, nor did it show up on the S meter. All other bands I could not find a difference in noise floor or birdies between off and on. Leigh/WA5ZNU >> The Q of a 5 Farad capacitor is not good. It will carry the peak >> current from a SSB transmitter but it will not control RF noise. This >> comes from the high frequency chopping of the input 120 Volts. MFJ >> has some inductors and low value caps in their power supply to >> control RF noise. >> >> A 5 Farad cap is not cheap. I guess that is why it is more expensive. >> > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Ron D'Eau Claire-2
On Oct 1, 2006, at 10:34 AM, Ron D'Eau Claire wrote: > Tod, look for a short in the +12 circuit to ground. The swollen > batteries > suggests they were feeding lots of current into a dead short for a > long > time. > > Open the unit and do the resistance checks at the top right column > on page > 54 of your manual. If those checks disclose a short, follow the PCB > traces > back to the power switch. You may find that one carrying +12 has > burned open > from the heat of the batteries. All checked out OK I just completed the voltage checks on page 27 of the assembly manual Here's a comparison of the results when working versus now U1 pin 1 was 4.94v now 19.5mV U3 pin 6 was 6.05v now 2.47v D2 Anode was 14.83v now 2.7v D2 cathode was 13.75v now 2.5v Voltage measured at the supply is 12.3v (Astron AS-35) Tod ---- Tod Glenn N7WD NAQCC #1283 SKCC #1444 FISTS #12134 ARCI #12420 [hidden email] _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Tod,
Somewhere between your power supply and the anode of D2, there is a problem. It may be a high resistance in a connector or a burned PC board trace or a relatively low resistance (but not zero) path to ground which is dragging down the power supply output. With the power source de-energized, check all the connections and make a continuity check from the power supply positive terminal all the way to the anode of D2 - you should find zero ohms, AND (caps because it is often overlooked), check continuity from your power supply negative terminal to the KX1 ground - this should also be zero. If the continuity checks look good, then power it on and check the power supply voltage right at the power supply output. If it is the same as the voltage to ground that you read at D2 anode, then you can blame the power supply itself rather than the KX1, but if you have full power supply output at the supply terminals and something different at the anode of D2, make the continuity and connector checks again - these points should be connected and as a result of that connection they should be at the same voltage. 73, Don W3FPR > -----Original Message----- > > I just completed the voltage checks on page 27 of the assembly manual > > Here's a comparison of the results when working versus now > > U1 pin 1 was 4.94v now 19.5mV > U3 pin 6 was 6.05v now 2.47v > D2 Anode was 14.83v now 2.7v > D2 cathode was 13.75v now 2.5v > > Voltage measured at the supply is 12.3v (Astron AS-35) > > Tod > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Tod Glenn-2
>
The input power seems to be shorted to ground. This could be a shorted
> All checked out OK > > I just completed the voltage checks on page 27 of the assembly manual > > Here's a comparison of the results when working versus now > > U1 pin 1 was 4.94v now 19.5mV > U3 pin 6 was 6.05v now 2.47v > D2 Anode was 14.83v now 2.7v > D2 cathode was 13.75v now 2.5v > > Voltage measured at the supply is 12.3v (Astron AS-35) capacitor at C5 or C7 or possibly voltage regulator U8 or U9 has an internal short. With power disconnected and S1 and S2 in the OFF position, measure the resistance between ground and the cathode of D2. If you have a short, then C2 is probably shorted. If this is not the case, next measure between ground and the out put of each voltage regular (U8, U9) in turn. If you have a short on either regulator then it is probably bad. If you still don't have a short then measure between ground and the input of either voltage regulator. If you have a short then C7 is probably shorted. Replace the bad component and repeat these measurements before turning power back on. Larry KB5DXY _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Tod Glenn-2
On Oct 3, 2006, at 1:35 PM, <[hidden email]> <[hidden email]> wrote: > ---- Tod Glenn <[hidden email]> wrote: >> >> On Oct 1, 2006, at 10:34 AM, Ron D'Eau Claire wrote: >> >>> Tod, look for a short in the +12 circuit to ground. The swollen >>> batteries >>> suggests they were feeding lots of current into a dead short for a >>> long >>> time. >> All checked out OK >> >> I just completed the voltage checks on page 27 of the assembly manual >> >> Here's a comparison of the results when working versus now >> >> U1 pin 1 was 4.94v now 19.5mV >> U3 pin 6 was 6.05v now 2.47v >> D2 Anode was 14.83v now 2.7v >> D2 cathode was 13.75v now 2.5v >> >> Voltage measured at the supply is 12.3v (Astron AS-35) >> > > Tod, > > Take a look at the power cable and the power connector, J1. If you > measure 12.3V at the supply, you should measure very close to that > at the anode end of D2 unless there is an open or high resistance > in the power cable or in connector J1 or the PC board traces from > J1 to D2-anode or a short circuit in that area that is "pulling" > the supply voltage down. Try disconnecting the power cable from the > supply and measuring the resistance from the "+" supply lead to D2- > anode to check the path for continuity. If it's not very close to 0 > ohms, something is wrong. There's no continuity between + and the D2 anode > Do the same with the supply "-" lead to a ground (one of the > mounting standoffs should work). That path should also be very > close to 0 ohms. While your measuring, measure from the power cable > "+" to "-" to insure it's not shorted. > > If you do find an open or a short in the power path and it's not a > soldering defect, look again for a short circuit on the "V+" signal > line shown on the schematic. Check this by measuring the resistance > from L3 on the bottom of the board to one of the mounting > standoffs. (This would be the first step on page 55 of the assembly > manual). If it measures less than 500 ohms, there is a short circuit. The resistance between L3 and ground is about 1 K. ---- Tod Glenn N7WD NAQCC #1283 SKCC #1444 FISTS #12134 ARCI #12420 [hidden email] _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Tod,
Ok, you have an open circuit somewhere between the power supply and the anode of D2 - there are only a few pieces involved - the wire in the power cable, the male connector, the female connector in the KX1 and a bit of PC board trace going from the connector to the anode of D2. Continue the continuity testing on each piece and possibly through the mated connectors - sometimes connectors will fail to mate properly if one of then does not have adequate spring tension in the contacts. You likely do not have a dead KX1, but you do have a dead power connection somewhere along the line. 73, Don W3FPR > -----Original Message----- > > There's no continuity between + and the D2 anode > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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On Oct 3, 2006, at 4:36 PM, Don Wilhelm wrote: > Tod, > > Ok, you have an open circuit somewhere between the power supply and > the > anode of D2 - there are only a few pieces involved - the wire in > the power > cable, the male connector, the female connector in the KX1 and a > bit of PC > board trace going from the connector to the anode of D2. Continue the > continuity testing on each piece and possibly through the mated > connectors - > sometimes connectors will fail to mate properly if one of then does > not have > adequate spring tension in the contacts. > > You likely do not have a dead KX1, but you do have a dead power > connection > somewhere along the line. Found the problem. The nylon shoulder washer is missing from Q6. There also seems to be a secondary problem with the external power in jack. If I connect the radio to batteries without the faceplate, it works fine. Looks like I need another power jack and shoulder washer. Thanks all. Tod ---- Tod Glenn N7WD NAQCC #1283 SKCC #1444 FISTS #12134 ARCI #12420 [hidden email] _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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