[Tamošius]

Greetings to the forum! A quick little about me, an a self taught electronics hobbyist going on some 15 years now. Started with vintage receivers, then test equipment and then post war tube radios. Not sure why, but have dove into pre-war octal tube sets and my first one is a Stromberg Carlson 130 in very nice shape, cosmetically. I have it up and running, had a bad output 6F6 tube with a burned cathode resistor and one of the candohm replacement resistors somehow went open. I noticed it is very deaf and after some learning figgered out it is only set up for a long wire antenna. So, would like to fabricate a loop antenna and not exactly sure of how to shoehorn it in.

I attached a full schematic, a partial schematic of the area involved and my proposed modification. I like to draw out to schematics to help learn the circuit hence the clean schematic pics. Incidentally, I discovered a couple years ago in my Grandpas old desk some schematic drawings that he hand drew sometime in the 1930's. He was also a hobbyist and we must be in tune with that way of learning.

Anyway, the inductance of the loop is somewhere in the 150uH range according to my calculations ((Upper Freq. of Receiver + IF Freq.) squared divided by Upper Freq. of Receiver squared x Local Oscillator Inductance in uH = Antenna Coil Inductance in uH). The oscillator inductance I think is ~90uH but that could be off as not sure if it measured correctly in circuit tho I did disconnect one lead. Assuming I can get the loop inductance figgered out, questions are:

#1 Does a 100pF cap need to be added the signal grid of the 6K7?
#2 Does C16 (.002uF) cap stay in circuit?
#3 Do I have the AVC spliced in correct?

I also will add a trimmer cap to tune the antenna. I also ordered some 180/46-44 Special Blend Litz Wire for the fabrication.

So, there it is! Look forward to some input and chatting.

Thanks,
Tom