09-28-2024, 07:40 PM
Strange thing about that speaker.
After I removed the transformer to try to use it with a PM speaker to align, the resistance of the FC became about 4.5K.
Then it sat awhile on the table, and the resistance increased to 6.5K.
I made an experiment: I put a 9V battery across the field coil, and then I measured the resistance, which became 4.5K again.
So I put the speaker back together and put it in the radio. It works fine.
Now about the radio.
Once the speaker was in, I powered it on and it hummed and motorboated, quite a bit.
Then I realized the shield for the 38 tube was missing. I have a spare from the sacrificial chassis, so I put it in, and the motorboating stopped, but lots of hum and noise remained.
TRhen I remembered to turn off my bench lighting, and the hum went down quite a bit.
Eventually I was able to receive one station (local), but the reception is very noisy.
I think I need to do two things:
1. Try to align it. As I use my isolation transformer, I think the Philco transformer for their generator (which they recommend) is not needed.
2. Buy a polarized AC plug. I am not comfy with the chassis being across 0.15uF cap[ from the Hot Line.
And I only have the non-pols.
Will continue....
After I removed the transformer to try to use it with a PM speaker to align, the resistance of the FC became about 4.5K.
Then it sat awhile on the table, and the resistance increased to 6.5K.
I made an experiment: I put a 9V battery across the field coil, and then I measured the resistance, which became 4.5K again.
So I put the speaker back together and put it in the radio. It works fine.
Now about the radio.
Once the speaker was in, I powered it on and it hummed and motorboated, quite a bit.
Then I realized the shield for the 38 tube was missing. I have a spare from the sacrificial chassis, so I put it in, and the motorboating stopped, but lots of hum and noise remained.
TRhen I remembered to turn off my bench lighting, and the hum went down quite a bit.
Eventually I was able to receive one station (local), but the reception is very noisy.
I think I need to do two things:
1. Try to align it. As I use my isolation transformer, I think the Philco transformer for their generator (which they recommend) is not needed.
2. Buy a polarized AC plug. I am not comfy with the chassis being across 0.15uF cap[ from the Hot Line.
And I only have the non-pols.
Will continue....
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.