Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

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




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
An attempt to remove the Field Coil from a G speaker
Mike; I've only run into a speaker with an open filed coil twice, and they were on newer speakers from the 1940s. One ...Arran — 12:48 AM
An attempt to remove the Field Coil from a G speaker
Arran Yes, this is my plan for now and what do I got to lose, this is not even the speaker from this radio, but one o...morzh — 10:44 PM
An attempt to remove the Field Coil from a G speaker
Mike;  I would unwrap the field coil, and see if maybe there a break near one of the ends, like where the coil wire att...Arran — 10:23 PM
An attempt to remove the Field Coil from a G speaker
...and this is what I did. I fed a little LT into the screwholes with a small brush, and a little on the rim next to the...morzh — 09:52 PM
Philco 40-120C Restoration
I combined the two 40-120C threads together as we like to keep the discussion of the same radio together. It helps with...klondike98 — 09:36 PM
Philco 40-120C Weak, Distorted Ouput
Just checked were I buy tubes price is four dollars. So living in Florid we have a local source for tubes. David    David — 09:14 PM
Philco 40-120C Weak, Distorted Ouput
The higher voltage may be due to higher mains voltage. My mains run 120-125AC when the set was new mains would be 110-11...David — 09:09 PM
Philco 40-120C Weak, Distorted Ouput
Thank you for your reply. I pulled a speaker from a Philco 41-221 and received the same result. I used a signal tracer t...bluecap — 08:45 PM
Philco 40-120C Weak, Distorted Ouput
Have you tried a different speaker? How did you trace the distortion? How do you know it is weak? What is the reference?...morzh — 08:33 PM
Philco 46-480 Electronic Restoration
Amen to that! Every time I think I’ve captured them all, I realize that there’s another error. My goal is to finish with...jrblasde — 07:00 PM

[-]
Who's Online
There are currently no members online.

>