Found an early 1950s Zenith AM/FM Clock Radio at Goodwill today!

[dieseljeep]

Originally Posted by Captainclock

How did this thread go from talking about a 1950s Zenith Clock radio to discussion about radio stations and what they do and do not air?

That's the way many of the threads work out around here.
It's been a little dry, regarding new topics. It's a good thing that there is a few members that are sharing their experiences with their projects.

[Captainclock]

Originally Posted by dieseljeep

That's the way many of the threads work out around here.
It's been a little dry, regarding new topics. It's a good thing that there is a few members that are sharing their experiences with their projects.

Well I'm having a bit of a problem with my Ol' Zenith it seems that (and I already mentioned this when I initially posted this thread) my radio's clock mechanism isn't working, tried swapping out the rotor thinking that maybe the original rotor may have seized up over the years (which is quite common for old Telechron movements) but even my known good telechron rotor didn't work on this clock and the transformer for powering up the rotor is still good as I can still hear it humming away when its plugged in, the only other thing I can think of is that the movement itself is seized up and that it needs to be oiled up but the clock is a pain in the butt to get apart because you have to actually remove the whole radio chassis itself out of the cabinet in order to get access to the clock movement and I already had it apart once tonight and I don't want to take it apart again right now, (at least not tonight) anyways do you have any ideas as to what could be wrong with the clock mechanism on my radio? Like I said the radio part works flawlessly yet, its the clock part I'm having issues with.

[dieseljeep]

Originally Posted by Captainclock

Well I'm having a bit of a problem with my Ol' Zenith it seems that (and I already mentioned this when I initially posted this thread) my radio's clock mechanism isn't working, tried swapping out the rotor thinking that maybe the original rotor may have seized up over the years (which is quite common for old Telechron movements) but even my known good telechron rotor didn't work on this clock and the transformer for powering up the rotor is still good as I can still hear it humming away when its plugged in, the only other thing I can think of is that the movement itself is seized up and that it needs to be oiled up but the clock is a pain in the butt to get apart because you have to actually remove the whole radio chassis itself out of the cabinet in order to get access to the clock movement and I already had it apart once tonight and I don't want to take it apart again right now, (at least not tonight) anyways do you have any ideas as to what could be wrong with the clock mechanism on my radio? Like I said the radio part works flawlessly yet, its the clock part I'm having issues with.

Try turning the time-set knob. If it's real hard to turn, the clock movement is all gummed up.
The coil and laminations are known as the "field". Remove the field and rotor assembly and see if the pinion gear is turning. The output speed is 3.6 RPM.

[Captainclock]

Originally Posted by dieseljeep

Try turning the time-set knob. If it's real hard to turn, the clock movement is all gummed up.
The coil and laminations are known as the "field". Remove the field and rotor assembly and see if the pinion gear is turning. The output speed is 3.6 RPM.

I was finally able to get the clock to work, it turned out it was a bad rotor after all and the known good rotor I had wasn't installed correctly which is why it wasn't working with the known good rotor installed. Now I have a new problem, broken tuning string going from the tuning knob to the main tuning capacitor pulley, I replaced the original tuning string with a new one, but now I can't get the tuning knob to turn the tuning capacitor pulley, which would in turn rotate the pointer pulley, and I've tried stringing it every which way possible from what I remember it being strung up but no dice, what it does is that it will turn it toward the lower end of the tuning dial but it won't tune it toward the top of the dial because the tuning knob pulley just keeps rotating continuously within the tuning string and not actually turn the tuning string, and I don't have access to the service manual for this radio so I can see the stringing diagram for the tuner on this radio. It acts almost as if there isn't enough tension on the tuning knob but if I wrapped the tuning string anymore times around the tuning knob pulley I wouldn't have enough string to go around the tuning capacitor pulley, and its already wrapped around the tuning knob 4 times already (and 4 times is usually the maximum amount of times that I've seen tuning string wrapped around tuning knob pulleys on these old radios, because usually 3 times is the norm.)

[Captainclock]

UPDATE: finally got the tuner fixed, apparently 5 was the magic number as far as the number of times I had to go around the tuning knob pulley before going back to the main tuning capacitor pulley, which is odd because I've never seen a tuner stringing that required you to go around the tuning knob 5 times before. anyways, when I got the radio put back together I tested it out and the tuner was drifting really badly and also it would barely pick up any stations on the FM band except the really strong local stations.
So I took the radio back apart and checked all of the tubes in my tube tester and all of the tubes checked out fine except for a Raytheon 12AU7A tube that was obviously a replacement/substitute for the original 12AT7 tube in the radio, that tube was completely dead (no heater/filament glow whatsoever), so I replaced the tube with a correct 12AT7 tube that was a Telefunken branded tube and then put a new shield over the tube as the shield they had over it previously was just a cardboard tube that was painted silver, and then put the radio back together reattached the built-in antenna and fired up the radio and sure enough it was working perfectly again as far as reception goes, no drifting, and it was picking up more stations than before on the FM dial. Also I saw a date stamp on the radio chassis that dated the radio to 1962 (which I'm not sure if that's correct or not or if maybe the ink smudged just enough to make a 5 look like a 6) but either way it seems that I have this radio up and running again.

[Captainclock]

OK so what should I use to replace the old dry-rotted rubber gasket material that went between the clock dial glass and the cabinet? I was thinking of using that rubber tire patch material that comes in 2" strips for patching holes in tires temporarily, but want your guys' opinion as well, as far as what I should use.