Sorry Colin, I did mean <60 watts, not amps.
It's the radio that is seeing the intermittent SWR, not the amp. With the amp
totally pulled out of chain, the SteppIR never presents more that 2:1 for the
most part.
I have checked the SO-239 for bad joints, and have replaced the jumper between
the radio and amp with new coax and connectors. That hasn't eliminated the
problem either.
I do notice that the problem doesn't come up on a cold amp but seems to
eventually happen once the amp is in operation for a few minutes (10 or more).
Thanks for the response. Hope this offers a clue or two.
73,
Jack - WE5ST
Message: 5
Date: Fri, 24 Feb 2012 20:45:00 -0600
From: Jack Berry <jlberry@yahoo.com>
Subject: [Amps] Intermittent AL-811H SWR problem
To: "amps@contesting.com" <amps@contesting.com>
Message-ID: <0F319A02-F0BD-464C-8C40-5C1BD4F24577@yahoo.com>
Content-Type: text/plain; charset=us-ascii
I'm driving the 811H with <60 amps from a K3 into a SteppIR beam. I'm seeing
high SWR (as much as 24:1) come and go.
Changed interconnecting coax, etc.
With the amp out of the lineup the SWR is fine.
The reading I've done seems to say the tubes are failing. But I would think the
problem would stay if that were the case.
Any ideas?
Thanks & 73,
Jack - WE5ST
------------------------------
Message: 6
Date: Fri, 24 Feb 2012 18:49:03 -0800
From: "k7fm" <k7fm@teleport.com>
Subject: Re: [Amps] Intermittent AL-811H SWR problem
To: "Jack Berry" <jlberry@yahoo.com>, <amps@contesting.com>
Message-ID: <23AC59775DA84C77A13698A779398D62@COLIN>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I'm driving the 811H with <60 amps from a K3 into a SteppIR beam. I'm seeing
high SWR (as much as 24:1) come and go.
Changed interconnecting coax, etc.
With the amp out of the lineup the SWR is fine.
The reading I've done seems to say the tubes are failing. But I would think
the problem would stay if that were the case.
Any ideas?
Do you mean less than 60 watts? You say you are seeing a high SWR. Where?
Is it between the k3 and the amp or the amp and the SteppIR? Hard to
diagnose if we do not know the facts.
73, Colin K7FM
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