- 1. [Amps] GU74B's (score: 1)
- Author: "Dave Hachadorian" <K6LL@ARRL.net>
- Date: Mon, 24 Aug 2009 21:48:37 -0700
- I have a commercial amp that uses a pair of GU74B's (4cx800a's). Due to a recent cable failure in the filament circuit, there was no filament voltage, but plate voltage, screen voltage and RF drive w
- /archives//html/Amps/2009-08/msg00486.html (6,403 bytes)
- 2. [Amps] GU74B's (score: 1)
- Author: "Dave Hachadorian" <K6LL@ARRL.net>
- Date: Thu, 27 Aug 2009 15:46:28 -0700
- As several people predicted, my pair of GU74B's does not seem to have been damaged by accidentally running them without filament voltage. All is fixed now. Incidentally, this amp is a TenTec Titan II
- /archives//html/Amps/2009-08/msg00559.html (7,435 bytes)
- 3. Re: [Amps] Dimished Tube Life (score: 1)
- Author: "Dave Hachadorian" <K6LL@ARRL.net>
- Date: Fri, 25 Sep 2009 07:43:36 -0800
- Regarding 8877 tube life, I can tell you that in my working days we ran an 8877 amp at 250 watts output 24/7 for 15 years, without ever changing the tube. The amp was transmitting IRIG-B time code on
- /archives//html/Amps/2009-09/msg00312.html (8,429 bytes)
- 4. Re: [Amps] AL 1500 P.O. Meter Function (score: 1)
- Author: "Dave Hachadorian" <K6LL@ARRL.net>
- Date: Sun, 04 Oct 2009 19:33:06 -0800
- I own an Al-1500, and my buddy W7WW has two of them. We have found that the wattmeter is extremely sensitive to variations in swr or load impedance. It's a great amp though. Dave Hachadorian, K6LL Yu
- /archives//html/Amps/2009-10/msg00075.html (10,610 bytes)
- 5. [Amps] AL-1500 problem (score: 1)
- Author: "Dave Hachadorian" <K6LL@ARRL.net>
- Date: Mon, 02 Nov 2009 12:53:15 -0800
- My non-technical buddy across town is having a problem with his AL-1500 (8877 final). This problem shows up about 80% of the time when he first turns on the amp. When he first turns it on, after the
- /archives//html/Amps/2009-11/msg00012.html (7,555 bytes)
- 6. Re: [Amps] GU 74 operating parameters (score: 1)
- Author: "Dave Hachadorian" <K6LL@ARRL.net>
- Date: Wed, 06 Jan 2010 10:50:40 -0800
- I run a PAIR of GU-74B's. At 1500W output, for the PAIR: Ep = 2700 V Ip = 1 A Is = 30 ma Dave Hachadorian, K6LL Yuma, AZ _______________________________________________ Amps mailing list Amps@contest
- /archives//html/Amps/2010-01/msg00029.html (8,582 bytes)
- 7. Re: [Amps] trouble shooting Hunter 2000c (score: 1)
- Author: "Dave Hachadorian" <K6LL@ARRL.net>
- Date: Fri, 08 Jan 2010 10:26:58 -0800
- THIS MAY BE A HAZARDOUS SITUATION. THE GREEN SAFETY WIRE MAY BE CARRYING FULL PRIMARY CURRENT. The following discussion assumes that you are operating the amp on 240V AC. The schematic shows that the
- /archives//html/Amps/2010-01/msg00054.html (9,459 bytes)
- 8. Re: [Amps] trouble shooting Hunter 2000c (score: 1)
- Author: "Dave Hachadorian" <K6LL@ARRL.net>
- Date: Fri, 08 Jan 2010 10:37:46 -0800
- Also, make sure there is a fuse in BOTH sides of the 240 circuit. Dave Hachadorian, K6LL Yuma, AZ _______________________________________________ Amps mailing list Amps@contesting.com http://lists.co
- /archives//html/Amps/2010-01/msg00055.html (8,014 bytes)
- 9. Re: [Amps] Good amp to buy (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Tue, 26 Jan 2010 21:58:08 -0700
- AL-1500 with Chinese 8877 is solid at $2770. I have one with the Eimac tube. My buddy W7WW has one of each. Both of us run them at 1500 watts all day long in RTTY contests. The blower is a little lou
- /archives//html/Amps/2010-01/msg00369.html (7,467 bytes)
- 10. Re: [Amps] Good amp to buy (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Wed, 27 Jan 2010 12:27:25 -0700
- Here's an excerpt from the AL-1500 Manual: "NEVER REWIRE THE POWER SUPPLY TO BOOST THE HIGH VOLTAGE ABOVE 3700 VOLTS." At normal 3600 V, the Al-1500 puts out 1500 W with about 50 watts drive, so why
- /archives//html/Amps/2010-01/msg00382.html (8,506 bytes)
- 11. Re: [Amps] Good amp to buy (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Wed, 27 Jan 2010 13:18:09 -0700
- There are eight 450V caps in the filter string. At 4KV, you are really walking on the wild side. The caps won't get warm, and they won't hiccup. One of these days, you will experience the big bang. D
- /archives//html/Amps/2010-01/msg00384.html (9,629 bytes)
- 12. Re: [Amps] Converting a 76A to a pair of 3CX800's (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Sun, 7 Feb 2010 13:39:57 -0700
- The AL-1500 has a stack of eight 450V caps, and a plate voltage of 3600. 8x450=3600, so Ameritron didn't leave any headroom there. The manual cautions to make sure the plate voltage does not exceed 3
- /archives//html/Amps/2010-02/msg00204.html (10,488 bytes)
- 13. Re: [Amps] Band Decoder, TS950 (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Wed, 21 Apr 2010 15:34:44 -0700
- http://www.elecraft.com/KRC2/krc2.htm Dave Hachadorian, K6LL Yuma, AZ _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinf
- /archives//html/Amps/2010-04/msg00597.html (8,782 bytes)
- 14. Re: [Amps] 4CX250B Ratings in Dentron Clipperton V (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Sat, 22 May 2010 13:53:03 -0700
- Don't you peak the screen current with the TUNING control? Isn't the LOAD control set to produce the desired screen current at a particular level of drive? Dave Hachadorian, K6LL Yuma, AZ . ________
- /archives//html/Amps/2010-05/msg00304.html (8,476 bytes)
- 15. Re: [Amps] backwards plate transformer (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Tue, 1 Jun 2010 07:03:09 -0700
- I have used one of these. You will definitely need a surge limiter for when you turn it on. If you take the top cover off and shine a light into the oil, you will see a switch down there with selecta
- /archives//html/Amps/2010-06/msg00016.html (8,537 bytes)
- 16. Re: [Amps] SB-220 (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Sun, 13 Jun 2010 11:26:41 -0700
- The spitting noise is probably the tune capacitor arcing. That is a sign of underloading. Turn the load control more clockwise, and the spitting should stop. If your load control is already at max, t
- /archives//html/Amps/2010-06/msg00165.html (9,026 bytes)
- 17. Re: [Amps] New HF amplifier (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Sat, 31 Jul 2010 09:56:49 -0700
- Where can I find a new 8877 for $400? Dave Hachadorian, K6LL Big Bear Lake, CA . _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mai
- /archives//html/Amps/2010-07/msg00395.html (8,618 bytes)
- 18. Re: [Amps] Automotive Relays (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Tue, 3 Aug 2010 13:54:42 -0700
- Below is some info from W2VJN on inexpensive relays for RF. They are available for $2.43 each here: http://parts.digikey.com/1/parts/747811-relay-pwr-spdt-10a-12vdc-pc-mnt-jw1fsn-dc12v.html Dave Hach
- /archives//html/Amps/2010-08/msg00025.html (7,854 bytes)
- 19. Re: [Amps] AL-1500 Plate Meter Circuit (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Thu, 23 Dec 2010 14:24:24 -0700
- Page 9 of the instructions says, "The final grid current should be around 50 mA and the plate current below 1000 mA." By the way, the power output meter in the AL-1500 is not a real wattmeter, and ca
- /archives//html/Amps/2010-12/msg00321.html (8,992 bytes)
- 20. [Amps] Ten-Tec Titan III Model 417 meter bulbs (score: 1)
- Author: "Dave Hachadorian" <k6ll@arrl.net>
- Date: Sat, 26 Mar 2011 11:56:30 -0700
- All of the light bulbs in the meters on subject amp have blown out. I plan to replace them all with LED's. Getting access to the metering board looks like a hassle though. Has anyone done this job an
- /archives//html/Amps/2011-03/msg00210.html (6,867 bytes)
This search system is powered by
Namazu