[AMPS] Alpha 78 problem

Richard W. Ehrhorn w4eto@rmii.com
Sat, 10 Oct 1998 12:01:30 -0600


If I remember right there should be 10 ohms/25W on each side of the 240V line input.

73,  Dick

-----Original Message-----
From:	K7BG Matt Trott [SMTP:aa7bg@3rivers.net]
Sent:	Saturday, October 10, 1998 12:16 AM
To:	amps@contesting.com
Subject:	Re: [AMPS] Alpha 78 problem



>D44BC got a problem with his Alpha 78 amplifier, maybe some of yourguys
>can help us to guess what could cause this problem:
>
>When switching the amp ok evrything is ok. As soon as you apply drive,
>and anode current is flowing, the amp will switch off. You can switch it
>on again, some result than.
>
>We will visit D44BC for the CQWW CW contest. Would be nice to get his
>amp running.
>Thanks for your help!

There's a wirewound resistor in front of the xfrmr. Actually there are three
of them. THey can open when hot and cause the amp to shut off. I think the
one that went bad in my 374A was a 15w 10 ohm. Can't remember for sure.

If you need me to research the resistor further please let me know. I
replaced mine and it worked fine.

73. Matt--K7BG


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