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References: [ +subject:/^(?:^\s*(re|sv|fwd|fw)[\[\]\d]*[:>-]+\s*)*\[TenTec\]\s+255\s+Power\s+Supply\s*$/: 17 ]

Total 17 documents matching your query.

1. [TenTec] 255 Power supply (score: 1)
Author: Jim Anderson <ural.jim@gmail.com>
Date: Thu, 17 Feb 2011 21:06:38 -0800
I just picked up a 255 power supply for my Omni D and it has a pronounced hum. This is not coming from the speaker, but from the supply itself. The supply that came with the radio (non speaker type)
/archives//html/TenTec/2011-02/msg00308.html (7,408 bytes)

2. Re: [TenTec] 255 Power supply (score: 1)
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 17 Feb 2011 23:18:10 -0600
Check for a leaky filter capacitor. Check for loose transformer assembly screws, which can also be the mounting screws. Check for a steel case close to the core, maybe touching. Might take some stuff
/archives//html/TenTec/2011-02/msg00309.html (8,186 bytes)

3. Re: [TenTec] 255 Power supply (score: 1)
Author: "Charles P. Steinmetz" <charles_steinmetz@lavabit.com>
Date: Fri, 18 Feb 2011 00:45:05 -0500
Typically, this is caused by parts of the transformer moving with the magnetic forces generated. Sometimes the laminations are loose, which may or may not be cured by tightening the core bolts. Somet
/archives//html/TenTec/2011-02/msg00310.html (8,354 bytes)

4. Re: [TenTec] 255 Power supply (score: 1)
Author: Jim Anderson <ural.jim@gmail.com>
Date: Fri, 18 Feb 2011 06:38:05 -0800
Thanks for the replies. I'll open it up this weekend and see what I can find and report back. Jim K6JEA _______________________________________________ TenTec mailing list TenTec@contesting.com http:
/archives//html/TenTec/2011-02/msg00312.html (7,201 bytes)

5. [TenTec] 255 Power supply (score: 1)
Author: Jim Anderson <ural.jim@gmail.com>
Date: Sat, 12 Mar 2011 15:12:25 -0800
I am having a bit of a problem with my 255 power supply. That is the one with the speaker that matches the Omni D series. This started with a shut down due to high SWR. Normally when this happens the
/archives//html/TenTec/2011-03/msg00123.html (7,773 bytes)

6. Re: [TenTec] 255 Power supply (score: 1)
Author: "al sirois" <alsirois@roadrunner.com>
Date: Sat, 12 Mar 2011 18:24:43 -0500
Saturday evening I have a matching TenTec Power supply # 252-MO for the OMNI-D If someone needs it. $100.- + shipping. From 04544, Maine. Al Sirois, N1MHC P.O. Box 2 East Boothbay, ME 04544 207-633-5
/archives//html/TenTec/2011-03/msg00124.html (8,259 bytes)

7. Re: [TenTec] 255 Power supply (score: 1)
Author: Al Gulseth <wb5jnc@centurytel.net>
Date: Sat, 12 Mar 2011 18:33:14 -0600
I'd guess that one of the pass transistors bit the dust (shorted). When that happens the crowbar circuit fires and shorts the output to ground to protect the rig (as you alluded to with your comment
/archives//html/TenTec/2011-03/msg00126.html (8,958 bytes)

8. [TenTec] 255 Power Supply (score: 1)
Author: Jim Anderson <ural.jim@gmail.com>
Date: Sat, 12 Mar 2011 19:11:03 -0800
Thanks, I have done a bit more digging since I posted. If I pull the wire that leads from the diode bridge to the board with the pass transistors no fuse blows. If I pull the internal 20 amp fuse and
/archives//html/TenTec/2011-03/msg00128.html (8,057 bytes)

9. Re: [TenTec] 255 Power Supply (score: 1)
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 12 Mar 2011 21:20:53 -0600
Check the paralleled transistor junctions with an ohmmeter. The should be a difference in directions and not zero ohms. The symptoms are that the junction in at least one of the transistors is melted
/archives//html/TenTec/2011-03/msg00129.html (8,857 bytes)

10. Re: [TenTec] 255 Power Supply (score: 1)
Author: Jim Anderson <ural.jim@gmail.com>
Date: Sat, 12 Mar 2011 19:39:42 -0800
With the meter on Diode I get .513 in one direction and Open in the other. If I set the meter on the 2K ohm scale I get 1.18 but when I reverse the leads I get 1.2. Both transistors read the same. Ji
/archives//html/TenTec/2011-03/msg00130.html (9,443 bytes)

11. Re: [TenTec] 255 Power Supply (score: 1)
Author: Jim Anderson <ural.jim@gmail.com>
Date: Sat, 12 Mar 2011 20:23:50 -0800
After searching Google on how to test a transistor I realized I was doing it wrong. Here are the new readings... On the Diode function and the black lead on the base it reads .514 on one terminal and
/archives//html/TenTec/2011-03/msg00131.html (10,545 bytes)

12. Re: [TenTec] 255 Power Supply (score: 1)
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 13 Mar 2011 10:08:49 -0600
The transistors are wired in parallel, but that 0 resistance from base to one of the connections is a shorted junction in one of them. There's no repair possible for the transistor, it must be replac
/archives//html/TenTec/2011-03/msg00132.html (8,996 bytes)

13. Re: [TenTec] 255 Power Supply (score: 1)
Author: Jim Anderson <ural.jim@gmail.com>
Date: Sun, 13 Mar 2011 10:02:59 -0700
Is there a way to check the SCR? I pulled the board this morning and upon closer inspection it is discolored at the base where the leads emerge. I ordered a couple of the transistors from Mouser and
/archives//html/TenTec/2011-03/msg00133.html (10,116 bytes)

14. Re: [TenTec] 255 Power Supply (score: 1)
Author: James Duffer <dufferjames@hotmail.com>
Date: Sun, 13 Mar 2011 13:07:20 -0500
I don't know what kind of multimeter you have, but all meters do not have the red lead positive when in the Ohms position. When checking fwd and rev resistance of semiconductor junctions it becomes a
/archives//html/TenTec/2011-03/msg00135.html (11,544 bytes)

15. Re: [TenTec] 255 Power Supply (score: 1)
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 13 Mar 2011 14:54:35 -0600
Typically the SCR is not give enough heat sink to keep if from heating up, but its expected to see only a short burst as it blows the fuse. It should check open anode (postive) to cathode, but with a
/archives//html/TenTec/2011-03/msg00136.html (12,240 bytes)

16. Re: [TenTec] 255 Power Supply (score: 1)
Author: Jim Anderson <ural.jim@gmail.com>
Date: Thu, 17 Mar 2011 19:56:26 -0700
Though I would update this discussion. I received the transistors and SCR today from Mouser. Replaced the three components and all is well. Thanks for all of the help. Jim K6JEA _____________________
/archives//html/TenTec/2011-03/msg00158.html (8,596 bytes)

17. Re: [TenTec] 255 Power Supply (score: 1)
Author: Richards <jruing@ameritech.net>
Date: Fri, 18 Mar 2011 02:09:57 -0400
Yippee ! (Never enough good news.) Happy Trails. == Richards / K8JHR == _________________________________________________________________ - _______________________________________________ TenTec mail
/archives//html/TenTec/2011-03/msg00160.html (8,755 bytes)


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