11-15-2020, 10:20 AM
Replaced (5 watt) wire wound resistors on the power out tube. Don't know why but since their replacement cracking and popping audio has disappeared. Listened to another good hour of clear and strong AM. Was considering aligning the AM but realized it had better sensitivity through the full frequency range of any AM radio I've worked on yet, so decided to leave alignment alone. Reinstalled the covers over the tuning cap and part of the FM circuitry. Once covers were installed listened and enjoyed AM stations I normally can't tune in. Next day received the new 12AT7 tube I suspected was the problem child of lost FM reception. Installed new tube, powered up the radio and was rewarded with reception of a few FM stations. More work needed, FM fairly weak, should be able to tune in over 50 FM stations but could manage only three. Was elated that FM was no longer AWOL. Guilty of patting myself on the back in congratulations for bringing a long dead radio back to life. Imagining in the near future of installing the chassis back in the cabinet, another successful project completed. Later the same day turned the radio on to enjoy listening to my AM and FM radio only to be rewarded with.... nothing. Only sound is static on both AM and FM. Returned the old 12AT7 just in case the new one at cooling developed a problem that opened the heater circuit. Still nothing. I know, more lazy fast trouble shooting, but I wanted my hard earned success back. Still nothing. Have left radio alone while licking my wounds and chastising myself for prematurely awarding myself the Best Retired Electronics Tech Award. While filling my days since the massive failure replacing the floor and hand rails on the backyard deck. I begrudgingly allow part of my brain to form a game plan to move forward slowly, again. Just like the old snakes and ladder game I played as a child. One more space and I win, only to have a bad roll of the dice, down the snake, and back at the beginning. Once my wounds are healed a bit, will humbly fire up the volt meter, check supply voltages. If all is well, time for the sig gen and injecting signals to see where they fail. Realized what a wonderful life I have when a cantankerous old radio is my biggest problem.