- 21. Re: [Amps] SB-220 tick,tick,tick (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Sat, 2 Feb 2019 08:49:19 -0700
- Yes. I replaced all of the electrolytics and equalizing/bleeder resistors. No sense in continuing to use the 40 year old electrolytics - some had a bubble in the rubber. I also yanked out the equaliz
- /archives//html/Amps/2019-02/msg00005.html (8,276 bytes)
- 22. [Amps] 3CX800A7 cathode short (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Fri, 15 Mar 2019 13:50:20 -0600
- I converted an Alpha 76PA to a pair of 3CX800A7's a few years ago. It's been a great amp since then. Last night something strange happened - It started drawing plate and grid current even before the
- /archives//html/Amps/2019-03/msg00021.html (7,176 bytes)
- 23. Re: [Amps] 3CX800A7 low grid current version? (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Sun, 17 Mar 2019 14:18:38 -0600
- This sounds like the same tube that Alpha was selling a few years ago. It was also touted as "low grid current". The specs are exactly the same as the standard tube, as far as I could tell. Alpha spe
- /archives//html/Amps/2019-03/msg00029.html (8,634 bytes)
- 24. Re: [Amps] QRO 2500DX MARK lll 4CX800 (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Sun, 31 Mar 2019 09:31:13 -0600
- I now know of two Chinese 3CX800 "low grid current" tubes that have recently failed in the same way. These, sold by RF Parts and Alpha Amps: https://www.rfparts.com/3cx800a7-tay-lgc.html In the two c
- /archives//html/Amps/2019-04/msg00001.html (9,261 bytes)
- 25. Re: [Amps] QRO 2500DX MARK lll 4CX800 (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Mon, 1 Apr 2019 13:34:48 -0600
- So, Carl, where would you suggest us cheap, constantly crying, hams get new, or at least new-old-stock Eimac 4CX800's and 3CX800's ? Lotsa luck. 73, Steve, N2IC Carl _________________________________
- /archives//html/Amps/2019-04/msg00006.html (8,917 bytes)
- 26. Re: [Amps] Removing grid shorts (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Fri, 31 May 2019 06:46:31 -0600
- I am the "proud" owner of two Alpha 3CX800's with grid-cathode shorts that start 2 minutes into warm up. I would be thrilled if they cleared themselves after 6 minutes of warm up. 73, Steve, N2IC Jim
- /archives//html/Amps/2019-06/msg00000.html (9,409 bytes)
- 27. [Amps] 3CX800 - a science experiment (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Fri, 31 May 2019 08:37:56 -0600
- As I have previously mentioned, I have two Alpha 3CX800A7LG's that appear to have grid-cathode shorts that develop within a few minutes of applying filament voltage. After seeing VE5RA's posting abou
- /archives//html/Amps/2019-06/msg00001.html (7,709 bytes)
- 28. Re: [Amps] GS35B Amps Common Problem / few more comments (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Wed, 6 Nov 2019 14:48:24 -0700
- Okay....I'll be stupid.... Besides the filament voltage and socket, what else would it take to convert something like a 3 tube Alpha 76 to a single 8877 ? Seems like the output Z is in the right ball
- /archives//html/Amps/2019-11/msg00044.html (11,055 bytes)
- 29. Re: [Amps] HIGH INPUT SWR ON GI7-B AMP (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Wed, 18 Dec 2019 13:47:25 -0700
- How did you determine the input impedance ? Tweaking or measurement ? 73, Steve, N2IC On 12/18/2019 12:29 PM, Bill McHugh wrote: Problem solved! After much gnashing of teeth and scratching of head,
- /archives//html/Amps/2019-12/msg00037.html (8,225 bytes)
- 30. Re: [Amps] Alpha on Life Support Again? (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Sat, 21 Dec 2019 12:34:52 -0700
- I hope their custom, Chinese 3CX1500 is better than their custom, Chinese 3CX800 that they were selling a few years ago. Myself and one other person (that I know of) had the same failure - grid to ca
- /archives//html/Amps/2019-12/msg00044.html (9,675 bytes)
- 31. Re: [Amps] Monitor RF output on computer screen (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Sat, 7 Mar 2020 15:48:40 -0700
- The ArraySolutions PM2 supports USB to the desktop. 73, Steve, N2IC also found the ACOM director free software links but the M0 web site is not coming up SLOW https://www.m0yom.co.uk/ does it work we
- /archives//html/Amps/2020-03/msg00015.html (10,987 bytes)
- 32. Re: [Amps] 3cx800 13.5Vac 3amp filament transformer (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Fri, 1 May 2020 15:20:12 -0600
- I have a Radio Shack 18 volt, 4 amp transformer that I have been using with a dropping resistor for a pair of 3CX800's. It makes me nervous, because if a filament opens on one tube, the filament volt
- /archives//html/Amps/2020-05/msg00000.html (7,946 bytes)
- 33. [Amps] Checking SB-220 meter continuity (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Tue, 26 May 2020 09:02:23 -0600
- The plate current meter in my SB-220 has gone flaky. R1, R2, R3 and the zener diode are fine. Sometimes, I can tap on the meter and it will come to life. Using something like a Fluke 87, what should
- /archives//html/Amps/2020-05/msg00045.html (6,709 bytes)
- 34. Re: [Amps] Checking SB-220 meter continuity (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Wed, 27 May 2020 11:21:01 -0600
- Thanks, everyone. The problem ended up being loose brass nuts on the meter. The meter resistance is around 1400 ohms, normally. 73, Steve, N2IC _______________________________________________ Amps ma
- /archives//html/Amps/2020-05/msg00048.html (7,220 bytes)
- 35. [Amps] HF-2500 T/R Relay (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Thu, 4 Jun 2020 11:32:28 -0600
- I'm looking for some pointers on how to access and replace the Commander HF-2500 T/R relays. It looks like it is below the input circuit box. What's the best way to disassemble to get to the relays ?
- /archives//html/Amps/2020-06/msg00008.html (6,491 bytes)
- 36. Re: [Amps] SB-220 6M conversion (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Sat, 6 Jun 2020 06:53:39 -0600
- Why are you running it in the CW position, instead of the SSB position ? 600 watts out in the CW position, with the HV you are seeing, doesn't sound far off. 73, Steve, N2IC All done "physically" but
- /archives//html/Amps/2020-06/msg00022.html (9,109 bytes)
- 37. Re: [Amps] Alpha 87A Power Supply Question (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Thu, 6 May 2021 07:56:55 -0600
- On 05/06/2021 01:03 AM, gudguyham via Amps wrote: Some of the old Henry amps actually require a neutral to be present when using the amp on 240v. On 120v it makes no difference because if you have t
- /archives//html/Amps/2021-05/msg00029.html (10,254 bytes)
- 38. [Amps] Drifting Power (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Sat, 16 Oct 2021 08:05:14 -0600
- I have a Commander HF-2500 Magnum, with a pair of 3CPX800's. Great amp. It has one quirk, and only on 15 meters. If the amp has been dormant for a while, the output power is initially low: about 1100
- /archives//html/Amps/2021-10/msg00068.html (7,441 bytes)
- 39. Re: [Amps] Drifting Power (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Tue, 19 Oct 2021 07:22:41 -0600
- Thanks to all for the many useful comments. To answer a few questions: 1) The input and output SWR remain constant while the power output is drifting. Using ArraySolutions PowerMaster wattmeters to v
- /archives//html/Amps/2021-10/msg00075.html (10,829 bytes)
- 40. [Amps] Alpha 76PA Conversion - Drive Issue (score: 1)
- Author: Steve London <n2icarrl@gmail.com>
- Date: Tue, 30 Nov 2021 14:09:24 -0700
- 6 years ago, I converted a 3x8874 Alpha 76PA to a pair of 3CX800's. The tubes were the Chinese ones that Alpha was selling for a while. Even after removing the resistor pack in the input circuit, I h
- /archives//html/Amps/2021-11/msg00028.html (7,346 bytes)
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