Scratch Suppressor on AM/FM Philharmonic

[Tom Jardine]

The scratch suppressor works well when listening to broadcast audio, but does not respond to phono audio. I found an undocumented switch that is part of the radio/phono wafer switch on the "Fidelity" shaft that turns off the screen voltage to the 1st & 2nd IF 6K7's when in phono position, not the 3rd and 4th IF's. I do have screen voltage on the 6B8 suppressor tube, ~108 vdc when not in phono, 122 when in phono position.  Tom

[Tom Jardine]

I should have said I have the 108/122 vdc before the 200K resistor going to the screen of the 6B8.

[jimmie o. ashabraner]

  I get very little response on my philharmonic on phono or broadcast audio, but do like the volume expander on broadcast audio. But I am very pleased with the radio as it is very sensitive and has great sound and is probably the only radio I own that is not affected by neon transformers illuminating neon tubes near the radio

( tube radios are usually very likely to pickup neon noise on AM, not FM)

was in the neon sign business for 30 years and installed white neon in a ceiling cove to reflect light off the ceiling. I told him it might interfere with radios and other electronics but he wanted it anyway and learned he had to switch off the neon t o stop interference, jimmie ashabraner

[Tom Jardine]

Jimmie,

I've had this radio a long time and the scratch suppressor has worked on phono in the past. What I can't remember is whether it was working with a ceramic pickup at the time or, as it is now, with a magnetic cartridge and a single tube preamp. I tried inputting a separate AM/FM tuner into the phono input and the suppressor refuses to limit the highs as it does on the radio. I've recapped it since and checked and rechecked my work. You apparently have an earlier beam of light set or dial pointer set if you have the volume expander. Do you have the optional tweeters?

Tom

[jimmie o. ashabraner]

yes it is a 1940 beam of light ( no fm) I don't have the tweeters. thanks for your interest, jimmie

[Tom Jardine]

Jimmie, I have the Georgian cabinet.

[jimmie o. ashabraner]

I don't have a cabinet for my Philharmonic, yours sure is pretty, jimmie

[Tom Jardine]

The cabinets are more scarce than the chassis. The Philharmonic is adaptable to sitting on top of a shortened Philco/Zenith/whatever donor cabinet. I'll see if I can find a picture. I built a cheapo cabinet for my RCA Berkshire chassis and power amp.