McIntosh MR71 FM Receiver Video #14 - IF Alignment

I take the simplest approach to aligning the IF stages following (mostly) the alignment instructions in the manual.

[fbloggs]

These videos remind me of those 70's computer adventure games that begin with: "you're standing in a maze of twisty little passages going off in all directions, and it's dark" After hours of trials you''re still lost along with Jim and feeling your way along the walls, some of which you forgot to chalk as you went. The tour guide is lost too, so you're all along for the ride. After this series of videos you might decide that you're now equipped to embark on a career or hobby, repairing and re-aligning radios or you might instead to just forget it and go watch tiktok videos. Life is so short and one has to weigh to pros and cons, especially if you;re getting on in years.

[ABOQ]

When you tune IF transformers in an FM receiver you should tune it with the modulation off and the afc off. This is because the FM receiver is designed to reject AM signals, and receiving AM signals on an FM receiver will be distorted.

[SoddingaboutSi]

Are you sure the core that gave the big jump is not the discriminator Jim? If so that should be nul on the tuning meter on most tuners. Just checking sport.

[YouAllKnowBob]

Interesting radio. I don't understand why they wanted those coils shorted either. I also don't understand why they have the filaments of some of the tubes hooked to the 95 volt supply! I guess they do things different in New York.

[DAVIDGREGORYKERR]

I think the bandwidth is set wide to accommodate the baseband which is 20-22050khz, 19khz carrier and 38khz DSB difference signal so the bandwidth would probably be 75khz as when 38000+22050 is 60050khz so 75khz bandwidth is most likely.