05-26-2019, 02:00 PM
Hi, everyone:
While looking for something else (and waiting on a shield and new ring for my 71B discussed above), I stumbled on this little tidbit on Page 187 (185 in the PDF), of the Gernsback Radio Service Manual Volume 4:
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Models 71 and 22L
Refer to Service Bulletins 128-128A
Below run No. 3 on 71-125B, run No. 2 on both 71-125 and 71-225; tone control (39) part number 05153 was changed to part number 04787. A part number 3903AH condenser was connected from plate of I output tube type (42) to ground on chassis.
The tube shield used on detector amplifier tube was changed to new shield part number 8005.
Condenser (49) part number 3793-H was changed to part number 3793-R.
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(I don't remember where I downloaded the Gernsback books, but they were free on line somewhere.)
This refers to the different tone control I found in mine, plus the extra tone capacitor off the plate of the output tube, but more curiously, it refers to a Bulletin 128A, that I have not found anywhere, which probably contains the updated schematic of the 71 Code 125 with shadow meter.
I hope someone in this Phorum can find and scan Bulletin 128A for those of us who may run across a Code 125 71 like mine.
Dan
While looking for something else (and waiting on a shield and new ring for my 71B discussed above), I stumbled on this little tidbit on Page 187 (185 in the PDF), of the Gernsback Radio Service Manual Volume 4:
\
-----
Models 71 and 22L
Refer to Service Bulletins 128-128A
Below run No. 3 on 71-125B, run No. 2 on both 71-125 and 71-225; tone control (39) part number 05153 was changed to part number 04787. A part number 3903AH condenser was connected from plate of I output tube type (42) to ground on chassis.
The tube shield used on detector amplifier tube was changed to new shield part number 8005.
Condenser (49) part number 3793-H was changed to part number 3793-R.
-----
(I don't remember where I downloaded the Gernsback books, but they were free on line somewhere.)
This refers to the different tone control I found in mine, plus the extra tone capacitor off the plate of the output tube, but more curiously, it refers to a Bulletin 128A, that I have not found anywhere, which probably contains the updated schematic of the 71 Code 125 with shadow meter.
I hope someone in this Phorum can find and scan Bulletin 128A for those of us who may run across a Code 125 71 like mine.
Dan
"Why, the tubes alone are worth more than that!" (Heard at every swap meet. Gets me every time!)
Philcos: 90, 70, 71B, 610, 37-61 40-81, 46-420 Code 121 to name a few.
Plus enough Zeniths, Atwater Kents and others to trip over!
