[Guest]

Hello,
I am in the middle of restoring a Philco 48-482. I have recaped and replaced all of the out of tolerance resistors. Radio works great in AM and SW.
However the FM does not. I traced it down to the FM detector. L300 is open in the cathode circuit of the FM1000 tube. Is anyone familiar with this model, where you can tell me the value of the coil? I have the riders service info, but it doesn't show a value. Any help would be greatly appreciated.

Thanks

Dave

[Chuck Schwark]

Since L300 is a simple RF choke with a phyisically small winding, I'd look for the wire break at the connections to the wire leads.

Philco gives no inductance value for this coil in any Philco Parts Catalogue I have.

If you have to unwrap a few turns to get to the break it's not critical. Or if the break is way inside the coil, just re-wind that small coil with the same gauge wire to approximate the number of turns. It does not have to be pi-wound like the original. Just keep the turns "globbed up" in the center of the form.

[Guest]

Chuck,

Thanks for the heads up and steering me in the right direction. The coil was broken (burn't) about a half a turn in. Made the repair, the coil now reads 8 ohms and 183uh. I will put it back into the radio tomorrow evening
and see what happens.

Thanks again,

Dave