11-25-2020, 12:19 AM
I finally got it to pickup a number of radio stations (not just WLW), a full NOS tube swap out (except rectifier) and a slightly longer antenna coil. The audio was weak and distorted but it was there.
The same audio distortion increases in amplitude when the screwdriver contacts the primary of the 2nd IF transformer. That makes me wonder if this is a problem area.
To date, the Philco 48-230 has:
New speaker
New output transformer
New NOS tubes, except rectifier
All electrolytic and paper caps replaced.
Antenna coil fabricated
Cleaned up tuner
Took dents out of 1st IF can and resoldered. Rust present on one trimmer cap screw
2nd IF can inspected and resoldered
It's definitely challenging to practice on.
I have some 455kHz crystals on order for making a fixed frequency oscillator so I can align this thing more accurately.
The same audio distortion increases in amplitude when the screwdriver contacts the primary of the 2nd IF transformer. That makes me wonder if this is a problem area.
To date, the Philco 48-230 has:
New speaker
New output transformer
New NOS tubes, except rectifier
All electrolytic and paper caps replaced.
Antenna coil fabricated
Cleaned up tuner
Took dents out of 1st IF can and resoldered. Rust present on one trimmer cap screw
2nd IF can inspected and resoldered
It's definitely challenging to practice on.
I have some 455kHz crystals on order for making a fixed frequency oscillator so I can align this thing more accurately.