[DaleHCook]

I am in the midst of upgrading and expanding my Universal Shop Speaker and Dummy Field Coil. I am getting ready to add a second dummy field coil to handle sets with tapped or split field coils. Such sets are rather uncommon. Rather than spend so much time with schematics that I'll need new eyeglasses I would like to ask you to name any Philco models that you know of which have tapped or split field coils. I need to see what range of resistances I should expect my second dummy field coil to have to handle. One benefit of this upgrade is that I will also be able to handle single field coil sets with high resistance (over 1700 ohms) coils.

[RodB]

The Atwater Kent Type L1 and L2 chassis has split fields at 560 ohms and 3000 ohms. The L2 300 ohm is also tapped. In addition the speaker has a third field coil not involved with ps filtering. I believe the Philco 511-514 series uses two filter chokes in the power supply; 275 and 1900 ohms.

[Ron Ramirez]

The Philco 511 Series does not use a field coil speaker - they use a magnetic speaker.

[RodB]

Right Ron, in the 511 series the 2 chokes are in the power supply.

[462ron]

Dale, several years ago I fixed a Radiotrope floor model for a friend. It is made by U.S. Radio & Television Corp. I understand other brands such as US Apex, Gloritone and Radiotrope, were made by them. In the radio I serviced, it had a split field coil with 3600/3000 ohm sections. Hope this helps. Your Universal Shop Speaker looks like a cool project!

Ron

[Ron Ramirez]

Right Ron, in the 511 series the 2 chokes are in the power supply.

The OP is asking about field coils.

Dale, I am not aware of any prewar Philco that uses a tapped or split field coil. I'm not saying there aren't any; there might be one or two that I can't remember/not aware of.

[DaleHCook]

Dale, I am not aware of any prewar Philco that uses a tapped or split field coil. I'm not saying there aren't any; there might be one or two that I can't remember/not aware of.

Ron - Thank you very much. You have seen more Philco models than anyone else I know of, so that is about as good as it gets. As far as post WWII sets go I don't generally work with those - the newest Philco in my collection is my 42-355. It is also my only prewar FM set. I am fortunate that I own instruments to work on its FM sections (SG-3U AN/URM-70 FM signal generator and HP Model 675A sweeping signal generator), and I have worked on many FM receivers up to 950 MHz over 40+ years, mostly specialized broadcast receivers (STL and remote broadcast) with a small number of consumer FM radios (of which my 42-355 is my favorite).