Amps
[Top] [All Lists]

[Amps] 3-500Z amp producing output with no input, why?

To: amps@contesting.com
Subject: [Amps] 3-500Z amp producing output with no input, why?
From: Bill Dzurilla <billdz.geo@yahoo.com>
Date: Wed, 16 Jun 2010 07:54:48 -0700 (PDT)
List-post: <amps@contesting.com">mailto:amps@contesting.com>
Hello,

My homebrew 6 meter 3-500Z amp has made the trip to Europe.  The only visible 
damage was that one of the lines to the filament pin of the 3-500Z had broken 
off.  I soldered it back on.

The amp powers up normally but something goes wrong when the PTT is pressed.  
Even with the rig set to SSB and the rig's power control fully 
counter-clockwise, the amp immediately produces hundreds of watts of output, 
even with no modulation.  In fact, the amp does this even when the RF input 
line from the rig is disconnected.  And if the RF input line is connected, the 
rig's internal power meter shows about 4 watts of output (the meter shows zero 
if the amp is not connected).  Also, the SWR is way off.  Barefoot, I read a 
1.2:1 SWR to the antenna.  With the amp on and generating the weird output, the 
SWR is over 5:1.

Any thoughts on what might be wrong and how to fix?  I tested it and it was 
working fine just before I packed it up to send to Europe.

73, Bill NZ5N/OM9ACA


      
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

<Prev in Thread] Current Thread [Next in Thread>