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Zenith AFC
#1

Perhaps not the best place for this post but here goes. There is a lot I do not know, the more I learn the more questions I seem to have about radio.

I had never thought much about AFC, locks a station on FM right? But while listening to a little plastic Z brand M723 one of the last tube sets they made I started to wonder. Where the AFC is usually on the band switch it made me think, wouldn't it make sense to just have FM band with the AFC as the only option with the regular AM? When you switch to AFC is the set using a tube to get the locking feature or is it another electrical component that is being incoporated into the circuit to gain this locking of a frequency? Why would anyone want FM with drift? You would think AFC is the standard. Why the choice?

I have heard some people tell me you get more sensitivity with no AFC but who wants the drift?  Icon_confused

Perhaps if I was better reading schematics this would be more obvious.

BTW when did AFC come into use, I have several older FM sets with no AFC.

The little M723 is OK, I pickup several low power FM Stations up here in Boston that evade other more modern FM sets I own. Sound is OK given smallish speaker but expected I guess. They are usually easy to find and inexpensive and where they were about the end of tube radio in the USA I guess they have a small place in collecting.

Thanks all.

Paul 

Tubetalk1
#2

I agree, some of the very late tube sets can be a lot of fun too. I have an old Delmonico (Early JVC) AM / FM / SW receiver I picked up for a song in rather sad condition. It was very tight to work under the chassis, but it is a nice little set, and receives quite well on just the two wire antennas that can be extended from the back, one for SW, and the other for FM




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