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Synchrodyne · 6th Dec 2017, 8:34 am

The American 6CY5 VHF tetrode was used as an FM RF amplifier as well as in the VHF TV RF amplifier role. An example was the Heathkit AJ-10 AM-FM tuner of 1960. At least from the schematic one gains the impression that the front end was a separate unit, whether of in-house or proprietary origin being unknown. The AJ-10 had a three-gang front end with a 6CY5 RF amplifier and a 6EZ8 triple triode as mixer, oscillator and AFC reactance valve. The same front end was carried over to the AJ-11 successor in 1961.

The AJ-10 was an “economy” model. The corresponding “deluxe” model was the AJ-30, which had a 6BS8 cascode FM RF amplifier and was generally more elaborate.

Cheers,

6th Dec 2017, 8:34 am	#15
Synchrodyne Nonode Join Date: Jan 2009 Location: Papamoa Beach, Bay of Plenty, New Zealand Posts: 2,944	Re: Mazda 30F27 RF tetrode for TV tuners. The American 6CY5 VHF tetrode was used as an FM RF amplifier as well as in the VHF TV RF amplifier role. An example was the Heathkit AJ-10 AM-FM tuner of 1960. At least from the schematic one gains the impression that the front end was a separate unit, whether of in-house or proprietary origin being unknown. The AJ-10 had a three-gang front end with a 6CY5 RF amplifier and a 6EZ8 triple triode as mixer, oscillator and AFC reactance valve. The same front end was carried over to the AJ-11 successor in 1961. The AJ-10 was an “economy” model. The corresponding “deluxe” model was the AJ-30, which had a 6BS8 cascode FM RF amplifier and was generally more elaborate. Cheers,