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

FM Dial won't line up
#1

Hi Guys,
Well, summer is over so it's time to get back to the winter hobby.
I'm working on a Zenith R723 AM/FM. All caps have been replaced resistors check and Th IF alignment is done. My problem is that when doing the RF alignment, when one part of the dial lines up with the right freq., the rest of the dial is off. If I set adjust it so 103MHz is correct on the dial. then 95 comes in at 92 on the dial. All freq above 103 line up but anything below is off.
Any ideas?
Thanks,

   

Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org

#2

WEFM was 99.5 and is denoted by a dot near the 100 marker on most every Zenith AM/FM set I have ever seen. You should see a dot right near the 100 on the outer band of stations which is FM on this set. Zenith had sort of an experimental station running well before FM was popular. I do not know if that helps a whit.

I have one of those sets and I never really thought too much about the lining up on the dial. It does well enough I can tune it. As I recall it has no AFC and can drift a bit.

If you get nowhere with it you can pm me and I may have a resource for you.

Good luck.

Paul

Tubetalk1
#3

L-3 (fm osc coil) has a bit too much inductance. If you can stretch it out bit will lower it's inductance. Once you get the low end close then use the trimmer to set the high end. On a lot of these sets it's tough to get them dead on across the whole band but should be much better than what you've got.

GL

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#4

looks like i have tubes you may want as spares.
#5

I've rarely had a tube AM-FM radio that truely lined up on the FM band. If they work well and can get the full range of stations, I just live with it myself. I've had a few that were very close, only to have them go out of alignment by simply replacing a weak 12AT7 with a new one. Icon_sad I am wondering if any tube sets were really dead on alignment with the dial on FM? It seems the advent of solid state FM tuning made that easier to attain and keep up.

No matter where you go, there you are.




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Model 27-84 BUZZ?Humm?
Depends on the type of hum. SOme is made by outside devices. Try installing an X-cap (0.2-0.5uF) across the AC line, ...morzh — 12:23 PM
Philco 40-120C Filament Wiring
Thank you for your replies. That is the correct schematic and pin out diagram for the rectifier. The resistance acro...bluecap — 11:01 AM
Philco 46-480 Electronic Restoration
Late last night a guy reached out in response to my posting on the Antique Radio Forum and suggested I contact Trust Aut...jrblasde — 11:01 AM
Philco 630csx power cord
Have you opened up that plug? It may be that the third wire is connected to that brass stud on the side of the plug and ...Arran — 02:57 AM
Model 27-84 BUZZ?Humm?
I would have to look at the schematic but it's not uncommon in 1930s AC radios to have the negative of one filter cap co...Arran — 02:46 AM
Model 27-84 BUZZ?Humm?
Hello Bruce, First all do mean a 37-84b ? Did you take any before and after pictures ? is it a buzz like when you touch...radiorich — 01:59 AM
B&K 1077B no video - problem solved
Hello Tim, Yes, I even check all of my replacement parts when I install them and I too had a capacitor go bad not long a...radiorich — 01:54 AM
B&K 1077B no video
I got back into it tonight. Problem found and resolved! Sometimes it helps to take a break and think things over. It was...TV MAN — 12:40 AM
6TPZ and 5TPO Radio Help
Thank you. I have to take a break from it for about a week. I'll have to do some thinking. I was toying with the idea ...R3Sons — 12:21 AM
Model 27-84 BUZZ?Humm?
Drowning in a overloud buzz/Humm. Have already changed filter caps,bakelite blocks( caps),out of speck resistors,checked...Bruce — 12:17 AM

[-]
Who's Online
There are currently 3677 online users. [Complete List]
» 1 Member(s) | 3676 Guest(s)
Avatar

>