[Vlad95]

After testing, the receiver turned on. But it didn't work right away. Testing all voltages revealed no abnormalities. The audio amplifier worked. Connecting the antenna (as if with a finger ) directly to the grid of the first amplifier allowed radio stations to be received. Further testing revealed an open circuit in the matching coil of the first RF circuit.
I had to remove the shield, which required drilling out the rivets. And yes, the coil was broken. Judging by its scorched appearance, this was caused by a lightning strike on the antenna.

   

But the open circuit was found and repaired. After that, the receiver worked quite reliably. To increase sensitivity, it was necessary to adjust the tuning capacitors of the RF coils.
In our opinion, the receiver doesn't work very well; a lack of gain in the audio path is clearly noticeable. Indeed, the very insensitive push-pull triode output stage is trying to operate directly from the grid detector. There is no additional gain stage. Therefore, the final volume was quite mediocre.
And yes, the aforementioned Philco-20A, whose circuit is largely identical, performs much better. At least the sound level is impeccable. This is precisely because the audio circuit includes an additional phaseinvertor driver after the detector.