08-25-2016, 03:18 PM
(08-24-2016, 04:31 PM)Eric Wrote: I got the 6v battery, It powers up and I get a wide variety of stations I still get a little hum from the speaker. I have tried both the SS vibrator and the original ( the original I have to give a helping hand to start vibrating so I'll stay with the SS) the hum is a little different in tone but still there. I'm just using a 4' PM speaker I had laying around. The speaker in the Schematic seems to show an inductor coil I'm I correct? My friend is working on getting a proper speaker for that model car.
< I'm just using a 4' PM speaker I had laying around.
Dang that's a biggin!!!!!
< Schematic seems to show an inductor coil I'm I correct?
Yes! But look at how it's wired. It's not wired as part of the HV filter. It's the field coil for the spkr and it provides the magnatizim for the spkr. It's powered by the 6v power from the battery. This won't reduce the hum level. There are two small caps connected to the VC, these are used to block rf generated from the vibrator contacts (arcing).
My take on this is that a regular pm spkr should work fine. I would try adding a bit more capacitance to the filters like 10 or 20mf to hear if that helps reduce the hum level. Also try connecting an earth ground to the cabinet, this may help w/rf pickup from the vibrator.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry