[Kenwood] Vexing Twins problem

[Mike Steussy]

Ahoy! Last January I posted a message to this group inquiring about a 
problem I was having with my Kenwood Twins, the T-599D transmitter and 
R-599D receiver. The symptom was a very slight change in frequency of my 
transmitted signal, noticeable only on CW. The signal went up and down 
in frequency just a few Hertz. And it did it at short, but irregular 
intervals. Pete Markavage WA2CWA and Mark Kenward K8VF kindly offered 
suggestions, which – over time – helped me find the solution, finally. 
Thanks, guys!

I could hear the shifts by using another receiver to listen to my 
transmissions into a dummy load. I noted them when the T-R relays in 
both transmitter and receiver cycled when the semi-break-in VOX delay 
timed out. When the relays didn’t cycle, there was no shift. The relay 
in the receiver has no plastic dust cover, so I wondered if the relay 
contacts might be dirty. I cleaned the relay using thin card stock 
soaked with DeOxit to rub over the tiny contacts. Then I fitted a 2x2 
inch ziplock bag over the relay as a replacement dust cover. The bag is 
held onto the relay base by narrow strips of plastic packing tape.

I tried the Twins on the air again and detected no shift. A friend on 
other side of town said it sounded great, no shift. I also fixed the 
VFO-on lamp in the receiver. It needed a replacement 12 volt 25 ma bulb 
from Radio Shack spliced onto the wires serving the original lamp. The 
lamp is very bright so I might put a second small resistor in series to 
give it longer life.

Thanks again to Pete and Mark for their kind assistance, which after a 
year, finally paid off.

73, Mike Steussy AE4R
Vienna VA