09-04-2023, 08:27 PM
Hi.
Have the radio here and it's now sorted and due to be wrapped up and returned.
The issue is that the removal of the preset buttons and associated wiring has removed some stray capacitance, that and the fact the valve lineup and lack of cathode resistors give this set very high gain. The IFs seem to have been peaked and I found that if they are slightly staggered the radio performs perfectly.
Decoupling was checked as perfect and no components were out of spec. I can only think it was a combination of changes to the self capacitance on the front end and possible twiddling in the distance past. The radio is very sensitive and in fact using a few feet of wire for an antenna works better than the loop that is in the following clip.
https://youtu.be/Dm2erpoIxyI
Have the radio here and it's now sorted and due to be wrapped up and returned.
The issue is that the removal of the preset buttons and associated wiring has removed some stray capacitance, that and the fact the valve lineup and lack of cathode resistors give this set very high gain. The IFs seem to have been peaked and I found that if they are slightly staggered the radio performs perfectly.
Decoupling was checked as perfect and no components were out of spec. I can only think it was a combination of changes to the self capacitance on the front end and possible twiddling in the distance past. The radio is very sensitive and in fact using a few feet of wire for an antenna works better than the loop that is in the following clip.
https://youtu.be/Dm2erpoIxyI
