05-17-2020, 05:03 PM
Tom
We know the heptode works from when you substituted the signal generator in place of the oscillator and a station came in. So I was trying to determine if the triode was conducting, and it is. It should be drawing a couple milliamps. Have you tried another tube? These are loctal tubes; have the tube pins been cleaned? If they are black or dark grey, clean them with 0000 steel wool and then alcohol. I believe the choke coil in the plate circuit was a work around to start the oscillator. It's hard to say at this point but keep it handy. I'm running out of ideas. When this happens I usually start poking around with a wooden or plastic stick to see if something is loose mostly around the tube socket.
We know the heptode works from when you substituted the signal generator in place of the oscillator and a station came in. So I was trying to determine if the triode was conducting, and it is. It should be drawing a couple milliamps. Have you tried another tube? These are loctal tubes; have the tube pins been cleaned? If they are black or dark grey, clean them with 0000 steel wool and then alcohol. I believe the choke coil in the plate circuit was a work around to start the oscillator. It's hard to say at this point but keep it handy. I'm running out of ideas. When this happens I usually start poking around with a wooden or plastic stick to see if something is loose mostly around the tube socket.
