K2 Deaf 20/30 metre band - the cure in my case

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K2 Deaf 20/30 metre band - the cure in my case

Malcolm Taylor
I'm happy to say that my newly finished serial number 4511 is working
fantastic. The CW only version. Now onto the SSB option. The parts and
packing were just excellent. I hit just two problems that I thought I
should share as this reflector was a really superb searchable help to me.
Thanks to everyone for that.

Problem 1) I decided to do the optional rx alignment PRIOR to doing the
transmit. My work bench is one end of the room with a good regulated power
supply but for quickness I thought I'd use a wall wart (12V) to test the
rx on an antenna the other end of the room. All bands worked great EXCEPT
80m. That band was terribly distorted. To cut a long story short the wall
wart was providing a reading on 15.1 on the K2. I changed the supply and
all was okay!

Problem 2) At the last testing stage, all bands were great EXCEPT 20/30
metres. I rechecked solder joints, toroids, you name it and then got
serious with a scope. To my surprise, C20 (RF board, 20/30 Pass Band) was
the culprit. A new 47pF cap was reading .18pF on my Almost All Digital LCR
meter. On replacing with my own stock 20/30 bands came alive. All bands
now excellent.

I suppose I could have damaged the cap with heat or pulling but I think it
may also have been a component fault. No blame attached to anyone but hope
this helps others. Happy building. What a great radio!

73, Malcolm, K1VZ

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