Quote:
Originally Posted by Arcanine
All I get is a blank, soundless image on all the other channels on both bands.
After it warms up, static shows up on the other channels and the image clears up.
https://youtu.be/iSkkBkEJiZs |
What other analog channels should you be receiving? If there are none, all the other channels would show nothing. Mine acts very similarly - only channel with any sound at all is the output of my DTV converter, channel 4.
I'd check the DC voltages on the IF transistors starting with the 1st IF. Keep it on station, with the antenna and fine tune stationary. Monitor what the collector voltage does when it acts up. If there is no change, move to the next IF stage (X1, X2, X3..) Your Sound IF comes off the last IF transistor(also serves as the first sound IF amp). Weak sound on mine was restored by replacing C412 and C413, per my markings on the schematic I have. C412 couples the sound to the volume control, and C413 is the bypass for X10, the 1st audio driver.
If it is an IF transistor, the 2SA162/2SA163 cross to both the 2SA453 and 2SA455, depending on which Sony Semiconductor Replacement Handbook you use. My 1977 one shows the 2SA453 and the 1981 shows the 2SA455 as the replacement. The sound IF amp transistor 2SA323 is replaced by 2SA182.