Iam working on my first radio project , It is a Phico 39-71 farm radio . When I hook up 90 volts to plate I get 90 volts to plate ,then I hook up 1 and half to filments ,And the voltage on the 90 volt side drops to 14 volts .That is not supposed to happen is it ? And if so .can you explain why ?Thank you Henry
Hi Hank & welcome,
>That is not supposed to happen is it ?
What are you using to supply the 90v?? If you are using 9v snapped together you may have some weak batteries. Current draw is going to be about 10ma which is about what the transistor set would use. May have a bad tube. Try pulling out one tube at a time and see if your 90 volts raises with both batteries connected.
Terry