- 361. Re: [Amps] Matchbox and relay (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Wed, 22 Apr 2020 05:29:45 -0500
- If I remember correctly, some of the passive components around the rectifier were intended to prevent the relay from hot switching. The KW Matchbox was intended to be an EFJ accessory to the famous D
- /archives//html/Amps/2020-04/msg00014.html (7,235 bytes)
- 362. Re: [Amps] Matchbox and relay (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Wed, 22 Apr 2020 15:47:30 -0500
- Wellll, that's a stretch. The KW MB was designed to handle 1 KW input phone and CW. On phone, that's roughly 700 w. output, modulated to roughly 2.8 KW. EFJ probably designed it with some degree of
- /archives//html/Amps/2020-04/msg00017.html (7,516 bytes)
- 363. Re: [Amps] DRAKE L4B (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Wed, 29 Apr 2020 05:50:24 -0500
- The cooling is wimpy because hams want quiet amps because most of them are appliance ops who don't understand the ramifications of poor cooling. Two things leap out from the photos: 1. Ditch the Cole
- /archives//html/Amps/2020-04/msg00027.html (7,076 bytes)
- 364. Re: [Amps] SB220 Meter blown (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Sat, 16 May 2020 06:41:58 -0500
- W8ZR is 100% CORRECT. You DON'T JUST WILLY NILLY SLAP ANY OLD DIODE ACROSS A METER! 73 Rob K5UJ -- For meter protection I also use back-to-back diodes across meter terminals. However, rather than usi
- /archives//html/Amps/2020-05/msg00024.html (8,846 bytes)
- 365. [Amps] HB 4-400 amp (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Tue, 2 Jun 2020 09:58:03 -0500
- You need to read Eimac document SK-300A Air System Socket. It will give you the socket and chimney for the 4-400A among other tubes. You need the SK-406 chimney. Lowering the socket a bit is okay but
- /archives//html/Amps/2020-06/msg00001.html (7,052 bytes)
- 366. Re: [Amps] SB220 running plate current when no drive; Problem found (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Tue, 6 Oct 2020 06:11:38 -0500
- 3-500s may still be in production but the cost is high compared to years ago and quality may be questionable. Good tubes in ham service should last for decades. There are SB220s out there with the or
- /archives//html/Amps/2020-10/msg00009.html (7,112 bytes)
- 367. [Amps] SB220 running plate current when no drive; Problem (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Thu, 8 Oct 2020 06:39:19 -0500
- Never heard of an ICAS rating for the 3-500. I have a dual 3-500 amplifier with a pair of 20 year old RF Parts 3-500s and they're still at full output, but they have been run conservatively especiall
- /archives//html/Amps/2020-10/msg00017.html (6,895 bytes)
- 368. Re: [Amps] SB220 running plate current when no drive; Problem (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Thu, 8 Oct 2020 13:03:55 -0500
- It depends on the plate voltage. You have to look at the Eimac data sheet to make a determination. As far as I know, the Eimac Data sheet is the standard the industry looks at when designing an ampli
- /archives//html/Amps/2020-10/msg00022.html (9,304 bytes)
- 369. Re: [Amps] SB220 running plate current when no drive; Problem (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Thu, 8 Oct 2020 13:05:13 -0500
- Where are you looking? At the characteristic curves? There's nothing for 4KV in typical operation; just max ratings. 73 Rob K5UJ _______________________________________________ Amps mailing list Amps
- /archives//html/Amps/2020-10/msg00023.html (9,138 bytes)
- 370. Re: [Amps] SB220 running plate current when no drive; Problem (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Thu, 8 Oct 2020 13:07:05 -0500
- If that's for a single tube, that's way too high. 73 Rob K5UJ _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
- /archives//html/Amps/2020-10/msg00024.html (8,835 bytes)
- 371. Re: [Amps] SB220 running plate current when no drive; Problem (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Thu, 8 Oct 2020 13:31:39 -0500
- You can go ahead and beat on a single 3-500 like that every day and I guarantee you'll be getting a new one in around 5 years. Especially if you operate high duty cycle or with a lot of compression.
- /archives//html/Amps/2020-10/msg00026.html (9,007 bytes)
- 372. [Amps] Really fancy Eimac tube (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Fri, 4 Dec 2020 05:50:48 -0600
- Looks like a prototype for a 4-400A. For that kind of money a fellow could buy several 4-400As NOS. Rob K5UJ _______________________________________________ Amps mailing list Amps@contesting.com http
- /archives//html/Amps/2020-12/msg00001.html (6,486 bytes)
- 373. Re: [Amps] Really fancy Eimac tube (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Sat, 5 Dec 2020 08:39:24 -0600
- If you look at some of the photos there are one or two with the seller's fingers holding the base and that establishes the scale and it's not a 4x1 because its base is bigger. Rob K5UJ _____________
- /archives//html/Amps/2020-12/msg00004.html (7,010 bytes)
- 374. Re: [Amps] History of Grounded Grid Amplfiers (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Tue, 15 Dec 2020 07:30:57 -0600
- I've had some experience with two 1 KW AM broadcast rigs, the Sparta 701 and Gates BC1G. Both meter the final PA plate current by putting the amp meter in series with the CT of the final PA filament
- /archives//html/Amps/2020-12/msg00020.html (8,895 bytes)
- 375. Re: [Amps] AL82 3-500 4-400 (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Wed, 27 Jan 2021 09:39:20 -0600
- The 4-400A is really designed for chimney use. The base is made to direct air up around the pins and out at the side of the base so it can travel up between the bulb and the chimney wall to the anode
- /archives//html/Amps/2021-01/msg00022.html (7,605 bytes)
- 376. [Amps] Clipperton L - GI-7B (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Sat, 13 Feb 2021 10:39:23 -0600
- There's nothing wrong with trying to achieve a better IMD spec. than the minimally acceptable ham radio level. It is fine and laudable to have a goal that is consistent with professional standards. T
- /archives//html/Amps/2021-02/msg00013.html (8,526 bytes)
- 377. Re: [Amps] Alpha 87A Won't Transmit (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Thu, 8 Apr 2021 05:45:19 -0500
- In my experience the problem is crappy off shore UHF females with pin cups that don't tightly grip the male center. Read this: https://forums.qrz.com/index.php?threads/a-rogues-gallery-of-panel-moun
- /archives//html/Amps/2021-04/msg00022.html (7,805 bytes)
- 378. Re: [Amps] Alpha 87A Won't Transmit (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Thu, 8 Apr 2021 09:38:08 -0500
- I don't know about the new DX Eng. crimp PL259s, but I've had an older crimp male go intermittent with the braid to metal crimp after a few years of use. I'm still soldering but almost all of my 3/8
- /archives//html/Amps/2021-04/msg00027.html (9,451 bytes)
- 379. Re: [Amps] Alpha 87A Won't Transmit (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Fri, 9 Apr 2021 06:01:10 -0500
- Everyone has their preferred way of doing this. That's why it's called amateur (not professional) radio. Rob K5UJ _______________________________________________ Amps mailing list Amps@contesting.co
- /archives//html/Amps/2021-04/msg00047.html (8,404 bytes)
- 380. Re: [Amps] Alpha 87A Won't Transmit (score: 1)
- Author: Rob Atkinson <ranchorobbo@gmail.com>
- Date: Sat, 10 Apr 2021 04:54:56 -0500
- Some of the tricks and techniques I've been reading here such as using a torch, filing the barrel, and enlarging the braid holes, indicate a misunderstanding about how heat should be applied. I tried
- /archives//html/Amps/2021-04/msg00063.html (9,727 bytes)
This search system is powered by
Namazu