[MrFixr55]

Hi Marsupial,

I am scratching my head here. I Although only a hobbyist, I am a 70 year old hobbyist and have been fixing and experimenting with electronics since I was 10. years old, even fixing phonographs for my Catholic elementary school in 5th grade when my older sister told her 8th grade teacher that I co0uld fix the classroom phono, which was older than me. I have fixed many a 1950s record player in my day. The average phono amp for a monaural ceramic cartridge consisted of one triode audio voltage amp and a pentode output. In other words, a 12SQ7, 50L6 and 35Z5 or 12AV6, 50C5 and 35W4; the amplifier and power section of an AA5 radio. For more power, a triode 1st audio, a phase inverter and 2 pentode outputs in push-pull, exactly like your radio. Many a phono with a crystal cartridge did not even have the triode 1st AF amp. They consisted of a selenium rectifier and a 50L6 with the heater in series with the motor which had a 70V rating.

Ceramic cartridges generally had an output of approximately 0.5V. Crystal cartridges had outputs as high as 3V. Magnetic cartridges had an output of 0.005 - 0.10V. This is why your radio has the phono preamp stage. A ceramic cartridge connected to this preamp should drive the amp into distortion.

My guess here is that either the cartridge is good and the phono preamp is bad, or (more likely) the phono preamp is good and the cartridge is bad. However, it is rare that one triode in a tube goes bad and the other is good. Ceramic and crystal cartridges do go bad and the turntable you have is 70 years old. My semi-educated guess is that the cartridge is bad.

If you have a HiFi or stereo amp, plug the turntable output into the aux input (not the phono input unless the phono input had a "ceramic" setting), and test for proper output.

Alternatively, if the radio plays loud and proud, then disconnect the connection from the phono preamp to the radio / phono switch, add an RCA jack and plug your audio from the turntable there and see how you fare. If the sound is lower than the preamp, then the cartridge is bad.

You should not need a transformer. The transformer was an impedance matching device to match the low impedance of the magnetic cartridge to the high impedance input. I have never seen a matching transformer used with a ceramic cartridge. In fact, I have never seen a matching transformer with a magnetic cartridge made since 1949. I have had turntables using the GE RPX cartridge lug into a preamp for a magnetic phono. There was no input transformer in the preamp.