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References: [ +from:n1rj@adelphia.net: 37 ]

Total 37 documents matching your query.

21. Re: [Amps] Building or Buying a Tuned Input Network (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Mon, 23 Jan 2006 14:11:55 -0500
If I remember my theory correctly, varying any of the pi network elements changes both the center freq and impedance match. You must have at least two elements variable to change CF and match indepen
/archives//html/Amps/2006-01/msg00546.html (9,928 bytes)

22. Re: [Amps] FW: Tuned input (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Tue, 24 Jan 2006 13:51:09 -0500
This would work fine when the input Z is near 50 Ohms (which most are). I think you would need a lot more than 300 pf to get the proper Q on the lower bands. 73, Roger -- Remember the USS Liberty (AG
/archives//html/Amps/2006-01/msg00582.html (6,924 bytes)

23. Re: [Amps] Here's something you don't see every day (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Tue, 14 Feb 2006 11:43:07 -0500
I have 2 cockatiels. I wonder how many bird watts I can get out of them? 73, Roger -- Remember the USS Liberty (AGTR-5) http://ussliberty.org/ _______________________________________________ Amps mai
/archives//html/Amps/2006-02/msg00251.html (7,403 bytes)

24. Re: [Amps] Tuned input board on SB-220 (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Fri, 24 Mar 2006 13:59:52 -0500
I'd be a lot more confident if there were some published figures for IMD products using an L network vs a Pi network. We really don't need more amplifiers spewing out higher levels intermodulation pr
/archives//html/Amps/2006-03/msg00644.html (8,823 bytes)

25. Re: [Amps] Tuned input board on SB-220 (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Fri, 24 Mar 2006 15:35:30 -0500
I just typed a msg to George, K6GT, and it occurred to me that an L net will not match 50 ohms to 50 ohms. It would seem to me that, if at some frequency/loading combination your amp looked like 50 o
/archives//html/Amps/2006-03/msg00648.html (9,572 bytes)

26. Re: [Amps] emtron dx-1??? for a couple hundred bucks? (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Mon, 05 Jun 2006 13:55:14 -0400
Look at the feedback! 73, Roger -- Remember the USS Liberty (AGTR-5) http://ussliberty.org/ _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesti
/archives//html/Amps/2006-06/msg00130.html (7,217 bytes)

27. Re: [Amps] 160m RTTY (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Sun, 30 Jul 2006 10:44:24 -0400
In the older LORAN A system the received envelopes were matched manually by the operator to establish the time difference reading. The later, and still current, LORAN C uses envelope matching for coa
/archives//html/Amps/2006-07/msg01381.html (7,641 bytes)

28. [Amps] Alpha 99 question (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Tue, 05 Dec 2006 14:17:21 -0500
I'm working on a friends Alpha that appears to have blown the screen regulator circuit. The circuit is a IRF 830 with the gate regulated at 360 volts by 4 Zeners. Two of the Zeners are 150 volt and t
/archives//html/Amps/2006-12/msg00029.html (6,481 bytes)

29. [Amps] Alpha 99 (again) (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Fri, 29 Dec 2006 15:30:58 -0500
This one has me stumped. I received the amp from a friend that said it got water into it that wicked down the rotator control cable. Upon inspection, I found the following problems with the screen re
/archives//html/Amps/2006-12/msg00222.html (7,077 bytes)

30. [Amps] Alpha 99 problem (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Mon, 15 Jan 2007 09:21:00 -0500
It now appears that the amp in question may have a bad tube socket. The sockets (GU74b) look like they can be disassembled. I'm thinking that the water got into the sockets and arced forming carbon t
/archives//html/Amps/2007-01/msg00157.html (6,426 bytes)

31. [Amps] SK1A socket for 4CX800/GU74b (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Tue, 16 Jan 2007 12:32:56 -0500
I need the annular screen bypass capacitor for one of these sockets. Has anyone modified their socket or have a defunct socket I could get? 73, Roger -- Remember the USS Liberty (AGTR-5) http://ussli
/archives//html/Amps/2007-01/msg00170.html (6,413 bytes)

32. [Amps] PSUD from Duncan Amps (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Thu, 15 Mar 2007 18:18:44 -0400
I was using this program to play around with power supply designs and I noticed something strange. If I expand the trace and look at the ripple component, the maximum voltage reported in the panel on
/archives//html/Amps/2007-03/msg00172.html (6,963 bytes)

33. Re: [Amps] Fault protection (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Thu, 22 Mar 2007 07:26:39 -0400
According to the manual, it's to protect the rectifier diodes. They say to replace with IRC type BTH only. 73, Roger -- Remember the USS Liberty (AGTR-5) http://ussliberty.org/ ______________________
/archives//html/Amps/2007-03/msg00300.html (8,228 bytes)

34. Re: [Amps] full range C vs. padders (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Sat, 31 Mar 2007 16:28:36 -0400
I agree a vacuum variable is the better solution. Another possibility is to use two dissimilar caps ganged together. In your case, say a 100pf and a 150pf. You use them in parallel for 160m, the 150p
/archives//html/Amps/2007-03/msg00420.html (9,583 bytes)

35. Re: [Amps] RE : amp hardware (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Fri, 13 Apr 2007 19:11:39 -0400
Many years ago when I was working in the 2-way radio business, I remember seeing a set of punches almost like a center punch with a tapered point. They were used to punch holes in fender wells, etc f
/archives//html/Amps/2007-04/msg00114.html (8,876 bytes)

36. Re: [Amps] New Guy, Old 813 amp (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Thu, 26 Apr 2007 14:29:32 -0400
I have a bit of heartburn with this scheme. The LDG tuner is an L network. The Q of an L network is not independently selectable. It depends on the ratio of impedances to be matched. For example, to
/archives//html/Amps/2007-04/msg00323.html (8,948 bytes)

37. [Amps] QRO-stuff (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Thu, 24 May 2007 10:16:50 -0400
This eBay seller has some vacuum relays I'm interested in. has anyone had any bad experiences ordering from him? I'm nervous about sending money to Russia without any guarantee of delivery of items p
/archives//html/Amps/2007-05/msg00194.html (6,587 bytes)

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