03-04-2015, 01:36 PM
Mike and Mike,
All electrolytics in the power supply were replaced (by me).
All electrolytics in the various audio amplifier boards were replaced by me, as were some (not all) of the original film caps. C19/20, C23/24, C29/30 are all new.
Mike (PhilcoMike), the service info does not state the DC resistance of the primary and secondary of the two interstage transformers. But hold the phone. My 440 does not completely match the schematic I added the link to previously, and mine is direct coupled - it does not have the interstage transformers. I never could find a schematic that matched my 440-T exactly, although this one comes close in many regards. See, Fisher was like Philco in that they made many running changes and apparently did not get all of them documented.
The audio signal in the photographs has been supplied by the Sencore AM-FM generator that you, Mike (morzh) were so kind to go over for me last year. It's a 10.7 mc signal applied to the input of the IF board, modulated at 400 cycles. So what shows in the pictures is 400 cycle audio.
I have the manual for that old Conar scope - somewhere. I don't remember where it is right now so I am at a loss as to just how to calibrate it to a known V/div quantity. To be honest, I never used the thing enough to become really proficient with it - I started using it as an output indicator many years ago and just stuck with that all of these years.
All electrolytics in the power supply were replaced (by me).
All electrolytics in the various audio amplifier boards were replaced by me, as were some (not all) of the original film caps. C19/20, C23/24, C29/30 are all new.
Mike (PhilcoMike), the service info does not state the DC resistance of the primary and secondary of the two interstage transformers. But hold the phone. My 440 does not completely match the schematic I added the link to previously, and mine is direct coupled - it does not have the interstage transformers. I never could find a schematic that matched my 440-T exactly, although this one comes close in many regards. See, Fisher was like Philco in that they made many running changes and apparently did not get all of them documented.
The audio signal in the photographs has been supplied by the Sencore AM-FM generator that you, Mike (morzh) were so kind to go over for me last year. It's a 10.7 mc signal applied to the input of the IF board, modulated at 400 cycles. So what shows in the pictures is 400 cycle audio.
I have the manual for that old Conar scope - somewhere. I don't remember where it is right now so I am at a loss as to just how to calibrate it to a known V/div quantity. To be honest, I never used the thing enough to become really proficient with it - I started using it as an output indicator many years ago and just stuck with that all of these years.
--
Ron Ramirez
Ferdinand IN
