03-21-2018, 02:18 PM
OK I promise this is last one, then it's back to hollow state.. Anyway I don't have another worthy of mention.. 
I've had this 1958 P-746A for probably 20 years but till yesterday it's never played a note.. Clean, apparently seen little usage..
After posting about the newer(1959) P-806A in the other GE thread I was fired up to repair it..
Replacing the electrolytics restored audio amp operation, otherwise still nothing.. Naturally not a easy one, found osc dead, voltages in ballpark.. I pulled xistor and checked with ohm meter, seemed OK.. Resistors all OK, caps mostly ceramic disc that I refuse to change.. I dig out the B&K xistor checker.. It's dead.. Arghhh... Got it open and found one of the P/S electrolytics shorted, replaced that, wa-la it's working(next in line for recap).. Checked transistor and found it somewhat leaky, approx 1.5X over allowable..
Naturally out of probably 500 ECG, SK, GE etc replacements, I don't have a low power RF germanium NPN on hand(several PNP).. OK since I had to be in Norfolk yesterday, I swung by the the only distributor remaining in area.. Well NTE 101 has such a limited calling these days, they don't have it.. BUT do have a 2N1994 that crosses to 101 and if I want that, its 50 cents!! Sure why not??
With the new xistor it sprang to life..
Chassis just before reassembly, new transistor in upper right, beside osc coil
...
Leaky 2N168A transistor and old caps, out of six one was still good
Back together and playing tunes...
I've had this 1958 P-746A for probably 20 years but till yesterday it's never played a note.. Clean, apparently seen little usage..
After posting about the newer(1959) P-806A in the other GE thread I was fired up to repair it..
Replacing the electrolytics restored audio amp operation, otherwise still nothing.. Naturally not a easy one, found osc dead, voltages in ballpark.. I pulled xistor and checked with ohm meter, seemed OK.. Resistors all OK, caps mostly ceramic disc that I refuse to change.. I dig out the B&K xistor checker.. It's dead.. Arghhh... Got it open and found one of the P/S electrolytics shorted, replaced that, wa-la it's working(next in line for recap).. Checked transistor and found it somewhat leaky, approx 1.5X over allowable..
Naturally out of probably 500 ECG, SK, GE etc replacements, I don't have a low power RF germanium NPN on hand(several PNP).. OK since I had to be in Norfolk yesterday, I swung by the the only distributor remaining in area.. Well NTE 101 has such a limited calling these days, they don't have it.. BUT do have a 2N1994 that crosses to 101 and if I want that, its 50 cents!! Sure why not??
With the new xistor it sprang to life..
Chassis just before reassembly, new transistor in upper right, beside osc coil
Leaky 2N168A transistor and old caps, out of six one was still good
Back together and playing tunes...
