Isolate the section by signal injection,and before that ground all control grid points one by one to bypass unwanted or overload side simply by .01/600vdc cap to ground And feed the I F signal or any radio frequency signals from detection stage towards IF and tuner side ,coupling cap for signal injection and view the output after detection on the volume hot audio point with oscilloscope For safety can use 100 pf to 1000pf in series with probe pin good luck and relax in between fault detection too needs pause mode for tea or coffee break to cheer up again to get the target of joy ful out put ✍️🌹
Excellent advice, Jim. Troubleshooting this one sounds like great fun! I haven’t forgotten to reply to your question about replacement for resistive power cords. Been ill and have also been busy catching up. Will post in the next few days. My Mum used to say it was Hell getting old. She was right!!!
at 2:50 the video shows that the speaker dummy load is connected between the speaker output and the standby connection and not ground meaning that both the speaker and standby leads are not connected correctly - according to the manual. The radio will not be hi-fi on the AM broadcast band but not too bad. The IF selectivity ranges are 5.0 KC, 2.5 KC, and 0.5 KC. all appropriate for the modes used for Amateur Radio. The calibrator crystal is a thing of beauty. The vacuum seal, the mounting and the large crystal tends to create a High Q component. I expect the calibrator is a highly stable device. If he keeps fiddling with it - it may destroy the integrity of the part.
Sorry to say so, but this receiver was doomed the moment it got put on his workbnch. Any receiver more complex than an AA5, and Jim is out of his element. Which is a shame since the service literature is comprehensive. And along with the basic knowledge the owner of a ham licence would have to have, this repair should be a manageable project. But as we know from the past, reading service manuals and following instructions is not for Jim. Time to dig another hole under that big oak - sorry, maple leaf - tree in the back yard and lay another soldier to rest. "Here lies Communications Receiver Specialist Halli Crafters SX-122. Born 1962, Died 2024 in the battle at Jim's Workshop."
Well if you want some feedback you will connect a 4 ohm resistor from the audio out to the standby connection. That connection goes to the cathode of the RF amp tube and to the cathode of the 50KC amp tube. So if you are one of Jim's friends - send him an email and explain it to him. I wish him the best but the logic here escapes me.
Reading the Title of the video "A Sinking Ship", I feel pity for said "ship". Since just like with the Titanic the sinking isnt so much the ship's fault, as more the operator's, who went head to head with that iceberg. And as with many sunk ships, there is ways to raise them... Especially if they are not sinking per se but merely listing.
Jim's radio shop I have a vintage zenith Trans oceanic transistor shortwave receiver I want to restore it let me no ware I can get Russian germanium transistors ?
Wether you are a hero or zero it hardly matters, loss and profit not the game of electron playmate,loss too a achievement to the other players honour tribute 🌹✍️
