[Collins] Need some KWM-1 help

Dr. Gerald N. Johnson geraldj at ispwest.com
Sat Apr 22 20:34:05 EDT 2006


I ran into W0WL, Warren Amfar at the Des Moines hamfest today. I found
out he'd been on the design team for the KWM-1. He admitted your VOX
relay turning on initially was normal. Not good but normal for the
radio. he approved of my mod putting a fixed bias on the cathode of the
relay tube. 

Here's how I'd do it. I'd measure the voltage from relay tube cathode to
ground with the VOX off, no audio. I'd then unhook that 680 resistor
from the cathode of the 6AQ5 and move that connection to ground. Then
I'd put a resistor from the 6U8 cathode to +275 that gave me that same
voltage on the cathode of thee 6U8 triode. I'm guessing something
between 33K and 100K, several watts.

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer



More information about the Collins mailing list