Re: Drake L-7
http://radiojim.exofire.net/pages/Glitch%20diodes.html -- F1AMM Fran?ois De la part de Peter Voelpel Envoy¨¦ : mercredi 29 janvier 2025 18:37
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Fran?ois
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#40992
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Re: Drake L-7
That clamp diode is typically a single diode. 73 Peter, DJ7WW -----Original-Nachricht----- Betreff: Re: [ham-amplifiers] Drake L-7 Datum: 2025-01-29T13:33:50+0100 Von: "Jim VE7RF via groups.io"
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Peter Voelpel
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#40991
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Re: Drake L-7
Does the following diagram correspond to your proposal? What is the green diode used for? -- F1AMM Fran?ois De la part de Jim VE7RF via groups.io Envoy¨¦ : mercredi 29 janvier 2025 13:34
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Fran?ois
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#40990
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Re: Drake L-7
A diode clamp is simply? a pair of REVERSE connected diodes, like 1N5408 / 6A10 / PM-600? type diodes.? ?They are wired between the B-? and the chassis.? Then the B- can never wander more than
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Jim VE7RF
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#40989
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Re: Drake L-7
https://www.w8ji.com/vacuum_tubes_and_vaccum_tube_failures.htm Anode systems should have series-resistance to limit peak current in the event of a tube arc or failure. That series resistance should
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Fran?ois
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#40988
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Re: Drake L-7
No problem Hal! 73, Evert <https://www.qrz.com/db/PA2KW> PA2KW / <https://www.qrz.com/db/5T2KW> 5T2KW / <https://www.qrz.com/db/W8S> W8S Sent: Tuesday, 28 January 2025 18:14 To:
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Evert Bakker
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#40987
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Re: Drake L-7
Gentlemen, My apology. I was thinking you were talking about Grid Bypass circuits of caps and chokes instead of Anode Bypass. As a compliment, the W8JI program of analyzing and preparing Anode Chokes
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HaL Mandel
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#40986
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Re: Drake L-7
Dear Everett et al, There are those that believe a Pi-Wound, or even a Solenoid-Wound inductor is the Saving Grace of QRO amplifiers. And there are those who think that monsters are really hiding in
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HaL Mandel
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#40985
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Re: Drake L-7
I was told that the original RF-choke could cause oscillation. 73, Evert PA2KW <https://www.qrz.com/db/PA2KW> / 5T2KW <https://www.qrz.com/db/5T2KW> / <https://www.qrz.com/db/W8S> W8S Sent: Tuesday,
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Evert Bakker
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#40984
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Re: Drake L-7
Thanks Dave. Always ¡°good¡± to hear the issues! In the L7 the RFC3 was ok (no issues in 15 years) 73, Evert PA2KW <https://www.qrz.com/db/PA2KW> / 5T2KW <https://www.qrz.com/db/5T2KW> /
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Evert Bakker
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#40983
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Re: Drake L-7
I've just bought 4 from W8JI at CTR Engineering. Installed one in my AL-1500 and one in my home brew 2 x 3-500Z 160 to 10 amp. No problems on any band with those chokes. 73, Alek VK6APK.
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Alek Petkovic
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#40982
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Re: Drake L-7
I found the RF-choke I used : https://www.rfparts.com/rfc3.html Thanks 225 ?H; that's a big value indeed. I thought you wound it yourself on the original mandrel. Why did you have to change this
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Fran?ois
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#40981
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Re: Drake L-7
From my own experience in blowing up two of those, is that RFC3 RF-choke purchased from RF-Parts is resonant on 30 meters when used in a 3-tube (8874) Alpha 76A amplifier. Use in other amplifiers may
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Dave w6de
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#40980
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Re: Drake L-7
I found the RF-choke I used : https://www.rfparts.com/rfc3.html 73, Evert <https://www.qrz.com/db/PA2KW> PA2KW / <https://www.qrz.com/db/5T2KW> 5T2KW / W8S <https://www.qrz.com/db/W8S> Sent: Monday,
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Evert Bakker
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#40979
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Re: Drake L-7
Francois, ** Your capacitor 'A' went with your old RF choke. Yes, you are correct. 73, Evert <https://www.qrz.com/db/PA2KW> PA2KW / <https://www.qrz.com/db/5T2KW> 5T2KW / W8S
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Evert Bakker
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#40978
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Dentron DTR-2000L info
Hi All, I have a DTR-2000L that I'm trying to bring back to life.? It's the same one that I asked about last year.? What I'd like is IF someone that has one of these amps, that's working, would you
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Kim Herron
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#40977
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Re: Commander HF-2500
Hi Alek, I¡¯ve seen some of the older units and worked on them. ?The real old ones had no grid trip circuit and so I made up a circuit board ?with a trip circuit and implement it on the old units.
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Louis Parascondola
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#40976
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Re: Drake L-7
Hello, ** No, I don't have the service manual for this amp. If you could share it with me, it would be appreciated. ** Your capacitor 'A' went with your old RF choke. A= 47 pF B= 307 pF Thanks for the
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Fran?ois
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#40975
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Re: Drake L-7
Fran?ois, here are the exact capacitors I used to replace C41 and C42 in my L7: https://www.rfparts.com/catalogsearch/result/?q=580050-7P https://www.rfparts.com/catalogsearch/result/?q=580300-7 **
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Fran?ois
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#40974
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Re: Drake L-7
Fran?ois, here are the exact capacitors I used to replace C41 and C42 in my L7: https://www.rfparts.com/catalogsearch/result/?q=580050-7P https://www.rfparts.com/catalogsearch/result/?q=580300-7 I
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Paul K6PO
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#40973
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