November 2, 2015

AF6 Tuner

This tuner is an update of the FM5 FM only tuner. A decent AM section was added and another classic was born. I listed some restoration tips below. I’ave also included the schematics. I sent a note to Greg Dunn to offer the schematics to him for posting on his site, His e-mail must have changed because I didn’t hear back. Anyhow, The schematics, pictorials and parts list can be found below. I scanned them from a service manual, and cleaned them up with Photoshop.

Repairs / restoration:

If you purchase an old AF6, several things will likely need to be attended to –

1) The blue ‘Tuned’ and ‘Stereo’ lights may be burned out. These lights are part of the muting circuit. If they don’t work, the muting won’t work. These bulbs can be replaced with Blue LEDs, with the appropriate current limiting resistors.

2) Capacitors – likely to be old and dried out. Replace all the capacitors in the critical circuits.

3) Clean the switches / volume control pot with Cramolin contact cleaner. This is the best.