THANKS to everyone who responded to my questions with information and
advice. As predicted, it was a valve failure and I have now fitted a new
(second hand) valve and everything is FB.
Ran 150w of RTTY over the weekend and did not even get warm.
Happy New Year and thanks again
Jim MM0BQI
----- Original Message -----
From: "Jim Martin" <MM0BQI@thersgb.net>
To: <amps@contesting.com>
Sent: Friday, December 06, 2002 8:57 AM
Subject: [Amps] Ameritron AL-80B
> I have checked the archives for problems with the AL-80 and found some
great
> information. My experience on this kit is limited and wanted to confirm
> some of the information.
> The original problem was no output and in the standby position the valve
> glows deep red. I replaced D17 (S/C) on the negative rail of the filter
> capacitors which can be damaged by a 'gas arc'?
> I now have about 150mA constant plate current and negative going anode
> current, all in standby position.
> The amp has had D17 changed previously and internally is in excellent
visual
> condition. It has sat in the same position since I bought it several
months
> ago and has not been used /AM! (Although it has been to VP8 on a
DXpedition)
> Just before the failure I applied 15watts of 10m RF when the amp was set
and
> tuned on 15m. Slight burning smell then no output.
> >From what I have read it looks like I need to replace the 3-500z. Before
I
> buy a new valve (and cancel the kids Christmas presents) I would
appreciate
> further comments
> Thanks
> Jim MM0BQI
>
>
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