Had a question on the this model. Why they chose to use two 12SQ7 tubes instead of one. It looks to me the first 12SQ7 is used as a dual diode after the second IF xfmr (RF detector) and the second 12SQ7 is used for the the AF amp and AVC (triode) not using pins 4 and 5 (diodes). The first 12SQ7 has the plate,grid and cathode all connected together and connected to B-. Was this used for better isolation of the Radio and Phono audio? Maybe they had a lot of surplus of 12SQ7s to use up?

Appears to me that this was done primarily for isolation purposes. This is a true radio/phonograph, not just a radio that the maker threw an phono input jack on for marketing purposes. Note that the Radio-Phono switch in Phono setting shuts off B+ to the mixer and IF tubes, eliminating all possibility of radio audio signal bleedthrough during phonograph operation. I suppose that Admiral could have chosen a plain triode for the first audio amp, but why use yet another tube type when the cost was probably about the same?

:Appears to me that this was done primarily for isolation purposes. This is a true radio/phonograph, not just a radio that the maker threw an phono input jack on for marketing purposes. Note that the Radio-Phono switch in Phono setting shuts off B+ to the mixer and IF tubes, eliminating all possibility of radio audio signal bleedthrough during phonograph operation. I suppose that Admiral could have chosen a plain triode for the first audio amp, but why use yet another tube type when the cost was probably about the same?

::Appears to me that this was done primarily for isolation purposes. This is a true radio/phonograph, not just a radio that the maker threw an phono input jack on for marketing purposes. Note that the Radio-Phono switch in Phono setting shuts off B+ to the mixer and IF tubes, eliminating all possibility of radio audio signal bleedthrough during phonograph operation. I suppose that Admiral could have chosen a plain triode for the first audio amp, but why use yet another tube type when the cost was probably about the same? That's what I thought why they did this. Some of the less expensive radio/phonos were designed on the cheap side. I have other radio/phono sets where you can hear the radio over the speaker with the record playing at the same time. I have three of the Admiral Radio/Phono sets in my collection. The cabinet is all Bakelite the top and bottom were molded in one piece. The grill is a molded diecast piece. This must have cost alot back in the good all days. Things were built to last. People back then didn't go out and buy every new model radio etc. They didn't pitch out items left and right like today with these I-Phones.