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Re: Potter & Brumfield Sensitive Plate Circuit Relays
Years ago the coil of a plate circuit relay was in series with the plate of a vacuum tube set up to conduct at the pull in current when the tube was biased on. Using ohms law, 0.009 A X 2500 ohms =
By Chuck Neal · #39735 ·
Potter & Brumfield Sensitive Plate Circuit Relays
All, I have an old homebrew RF deck that the T/R rely is a Potter & Brumfield LM11-2500. I can't find what the coil voltage is. In the 1954 P&B catalog the LM series is titled?Sensitive Plate Circuit
By Nick Jones KC0YKO · #39734 ·
Re: Alpha Amp Group Still Active??
Albany County Fasteners: https://www.albanycountyfasteners.com/Phillips-Pan-Head-Machine-Screw-M4-x-7-p/1066-1010.htm K9ER Lowes have them for delivery!! Home Depot seems to be down here in UK this
By Roy Talbert · #39733 ·
Ten-Tec Centurion Parts Needed
I have recently acquired a Ten-Tec Centurion model 422 that is in very nice condition, but has a blown up bandswitch and the plate tuning capacitor was arced.? I might be able to salvage the
By Omni · #39732 ·
Re: Alpha Amp Group Still Active??
Lowes have them for delivery!! Home Depot seems to be down here in UK this morning Im sure some specialists would have them cheaper for mail order When I am in the US on business I try and visit Home
By Fred Handscombe · #39731 ·
Re: Alpha Amp Group Still Active??
As in any quality-designed-and-built power amplifier, yes, there is a good-sized, large inductor from the output of the pi-network to ground to guard against exactly this kind of failure mode. What
By Steve · #39730 ·
Re: Alpha Amp Group Still Active??
Actually, they read "222M"; so it was clear they were 2200 pF. A 5 kV-rated cap is not likely to withstand 3 kV plate voltage under highly-mismatched circumstances at the legal power limit (such as
By Steve · #39729 ·
Re: Alpha Amp Group Still Active??
Did the caps short and put high voltage on the antenna causing the amp meter to peg? Is there a rf choke at the output connector?
By mike repinski · #39728 ·
Re: Alpha Amp Group Still Active??
Those oem 220M? caps are each 2200 pf.? ( 6600 pf in total for all 3 of em in parallel). The problem with discs is..... current handling capability.? ?Upper HF will result in the highest RF
By Jim VE7RF · #39727 ·
Re: Alpha Amp Group Still Active??
Actually, Adrian, I'm glad I didn't buy one of those, because finding short M5 metric screws here in the back-country of the USA would have been a real challenge? 8-D 73, Steve K0XP
By Steve · #39725 ·
Re: Alpha Amp Group Still Active??
I asked to join the 9500 group a week or two ago, but never heard back. I did search the 87A group's archives and have seen Glenn post there. But I've never seen any discussion of any other amp other
By Steve · #39723 ·
Re: Alpha Amp Group Still Active??
There is an Alpha 9500 group HERE: /g/Alpha9500 Glenn, AE0Q posts/replies there often. 73, Alan W5ARM
By Alan - W5ARM · #39722 ·
Re: W4ZT Amplifier Web Sites Gone
True, for that one cover page; however, the links don't go through the Wayback machine, so they don't come up with pages. One has to copy the indicated url for a link into wayback machine in order to
By Steve · #39721 ·
Re: W4ZT Amplifier Web Sites Gone
W4ZT.COM <http://w4zt.com/> IS GOOD. 73, Mike Mysliwiec KF8OD
By Mike · #39720 ·
Re: W4ZT Amplifier Web Sites Gone
Yes, indeed; but my point is that all of this fantastic old amplifier reference material is now on it's way gone... so anybody wishing to personally archive any of it had better get busy saving
By Steve · #39719 ·
Re: W4ZT Amplifier Web Sites Gone
Try the Internet Wayback Machine. There's a good chance you will find it there. Mod-U-Lator, Mike(y)/W3SLK
By Mike Sawyer · #39718 ·
Re: W4ZT Amplifier Web Sites Gone
Try with http://www.archive.org https://web.archive.org/web/20230830230406/https://w4zt.com/
By va3dxv · #39717 ·
Re: W4ZT Amplifier Web Sites Gone
Unfortunately, it seems that any reference to the original W4EMT's material is gone, too? 8-( 73, Steve K0XP
By Steve · #39716 ·
Re: W4ZT Amplifier Web Sites Gone
FYI¡­.I met Tony King many years ago for the first time at the Shelby, NC. Hamfest. ?Toby was with a group of guys including Ron K4POZ. ?They were best of friends and worked together on converting
By Louis Parascondola · #39715 ·
W4ZT Amplifier Web Sites Gone
Old news to some, perhaps... I think he died some time ago; but W4ZT's amplifier web sites, mostly showing big Russian tubes such as the GS-35B but also with links to many European Russian tube sites,
By Steve · #39714 ·