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[Amps] Alpha 77 start up

To: Paul Christensen <>
Subject: [Amps] Alpha 77 start up
From: Jan Ditzian <>
Date: Mon, 21 Feb 2011 17:31:07 -0500
List-post: <">>

I did some investigating and some testing.  First, two of the three 
bulbs were bad.  I cannot get these locally, so I have ordered both 
meter and switch bulbs on the internet and they will arrive in a few 
weeks.  Meanwhile, I put the good bulb into the standby switch, and it 
turns out that the delay appears to be working properly--the lamp lit 
after a few minutes warm-up.

Now comes the bad part.  I connected a dummy load to the amp RF output, 
and I connected the exciter rf to the amplifier (this is the first time 
that I have done this), and I connected the exciter relay switching to 
the relay connection on the back of the amp.  At this point, I saw that 
the swr on the exciter swr bridge was high.  I double-checked all 
connections, and used the same cable to connect the exciter directly to 
the dummy load, where the swr was 1:1.  I then thought that perhaps 
there was a stick relay in the amp, so I went ahead and connected 
everything back as one would expect to use th amp.  I pressed the CW/Low 
switch on the amp, and I turned the exciter power to zero and turned on 
the exciter, and then brought up the power a little.  I saw some grid 
drive at the amp but no plate current.  I unkeyed, turned up the exciter 
a little more, and the grid current went up a little more, still near 
the bottom of the meter.  I repeated this with a little more drive (the 
exciter still showing a high swr, and this time no grid current showed.  
I turned the amp off, and again checked to see the swr at the exciter; 
it was still high,despite the fact that it should have been looking 
directly at the dummy load through the amp switching.  Then I wrote this 

Jan, KX2A

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