08-15-2022, 04:29 PM
Bob,
Tnx.
Don't know that the missing choke/added resistor is the issue. The current at that point is very little 1/2w would be fine. What I'm seeing is that in the present setup you have 2K+100K to act as the plate load for the 75 tube. It could be a little low. A typical load would be about 250K-1M depending on the plate voltage. With the choke in the circuit the load impedance is going to be higher than what you have now but the dc resistance will be low. Think of it like an output transformer's primary. It's much more efficient than using resistor.
Does the amp section have good gain? If so then it's time to have to look at the rf and IF stages to see if all is well.
Tnx.
Don't know that the missing choke/added resistor is the issue. The current at that point is very little 1/2w would be fine. What I'm seeing is that in the present setup you have 2K+100K to act as the plate load for the 75 tube. It could be a little low. A typical load would be about 250K-1M depending on the plate voltage. With the choke in the circuit the load impedance is going to be higher than what you have now but the dc resistance will be low. Think of it like an output transformer's primary. It's much more efficient than using resistor.
Does the amp section have good gain? If so then it's time to have to look at the rf and IF stages to see if all is well.