04-24-2017, 09:26 PM
My guess is there is a problem with the mica trimmer. If you loosen the screw and it still does not peak, it seems to have too much capacitance to tune the coil to resonance.
You can try connecting a mica or ceramic cap in the range of 220 pF to 470 pF to the grid cap terminal of the trimmer (remove coil wire and grid cap wire) and connect the coil winding and grid cap wire to the other lead of the added cap. This will effectively place the added cap in series with the trimmer, reducing its capacitance, and you can see if the secondary coil will now peak.
You can try connecting a mica or ceramic cap in the range of 220 pF to 470 pF to the grid cap terminal of the trimmer (remove coil wire and grid cap wire) and connect the coil winding and grid cap wire to the other lead of the added cap. This will effectively place the added cap in series with the trimmer, reducing its capacitance, and you can see if the secondary coil will now peak.
