ZENITH Shutterdial Motor Drive Tuner

[Prairie Shade]

For you radio enthusiasts among us, show and tell again!! A 1939-40 Zenith Motor Drive Tuner Shutterdial . It reminds me of the old days when I had my picture taken in front of my grandfathers, AND my pants were wet. Oh well, some things never change. About 15 years ago a young man in the Lawrence KS area purchased a entire barn full of Zenith Radios from a sale in Western KS. He had over 500 radios (all zeniths) and was kind enough to do some trading for a couple that I was interested in. He kept most all of the balance and was going to open up a museum at one time. He went thru all my radios and replaced caps and resistors so they were OK to use. Like my hats, I dont want anything that I can use. Anyway, I always thought about the families who gathered around these in the evenings and what news about world events these sets had received. Anyway, again, thanks for opportunity to show and tell.

 

[Sefton]

Beautiful radio indeed! You're very lucky to have it. What style things had back then. It looks nice to have the family photos on top.

 

[Absinthe_1900]

My 1940 10S699 Zenith console.
I have the original booklet with all the station ID labels, I'm glad my Grandmother kept the radio & booklet.

When I got the radio all it needed was new caps, it's still running on all the original Zenith tubes.

I have another Zenith tombstone from 1938 as well.



If only I could find a Zenith "Strat", or a Sparton Nocturne, in an attic somewhere.

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[shamus]

Great Radios!

I have a 37 12 tube shutter that I'll post when I get home.

 

[shamus]

here's my '37 12 tube. Three band dial too.

 

[MK]

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I suppose those are ok...but it is not as nearly as stylish as this system:

On a more serious note....those are amazing radios. I have a 1928 Zenith but it is not as cool as the ones you guys have posted.

 

[shamus]

MK...

I just can't picture the kids sitting in front of that one listening to the lone ranger... It would be more like brittany.

 

[MK]

Agreed

That thing is cold and ugly.

 

[Absinthe_1900]

What you do with the modern system is hook it to an AM transmitter, then you can play old time radio CD's etc, and transmit the sound to your antique radio.

I have a one tube transmitter built by my local antique radio shop, then I can broadcast to all my old radios throughout the house.

It's legal, and a lot old old radio shops sell them for the customers, and there are a number of kits out there as well. (like Vectronics, etc)

 

[skyvue]

I acquired this Zenith shutter dial this weekend; I think it's from 1938. It seems functional, but I haven't figured out the tuning yet. Last night I could get two stations, but this evening, having changed nothing, I can't get the tuning arm to move even as far as it would last night.

I'm dying to just start using it, but I guess it's going to have to have some work (the friend who gave it to me said it was working fine for him, but maybe it suffered in transit). I'm getting sound and everything lights up -- it's just the tuning that's not working (I think).

 

[LizzieMaine]

The rubber dial-drive belt is either stretched out of size or broken. Get a new one from www.adamsradio.com and install it yourself in about five minutes, and you won't have any further problems.

 

[skyvue]

The rubber dial-drive belt is either stretched out of size or broken. Get a new one from www.adamsradio.com and install it yourself in about five minutes, and you won't have any further problems.

Thanks, Lizzie. I'm not the handiest of men (and I've never worked on a radio); would you still say it's something I could handle?

BTW, the radio came from up in your neck of the woods, relatively speaking. The friend who gave it to me lives in Standish.

 

[LizzieMaine]

There was evidently a very active Zenith dealer up in this part of the country -- those turn up fairly often around here in barns and sheds and at estate sales. I had a chance to get one a couple years ago, but I didn't have anywhere to put it so I passed -- someone else gobbled it up the next day.

All you'll have to do is pull the chassis -- you'll see where the belt goes once you've got it out of the cabinet.

Word to the wise -- Zenith didn't engineer its power supplies very well, and they often used a rectifier tube (the 6X5) which was prone to short circuiting and toasting the power transformer. Some people replace these tubes with solid-state substitutes for safety, but others say it's OK to leave the original tube in place as long as you don't leave it running unattended. If you should ever smell anything like burning tar or see smoke, pull the power cord immediately.

 

[skyvue]

Great, thanks. I'll ask one more question of you, if you don't mind. This model has two tuning needles/arms/hands (not sure what they're called), and it features something called Robot Tuning (there are two tuning knobs). Are you familiar with that style of tuner? Is there a chance it'll require two dial-drive belts?

 

[LizzieMaine]

Robot Tuning was Zenith's trade name for a motor-driven automatic tuning system -- you'd pre-set stops for your favorite stations, and you could use the Robot Tuning mechanism to tune them in at the push of a button. Most manufacturers offered some variation of this between 1937 and 1940, after which electronic push button tuning, which cut in coils tuned to specific frequencies in place of the main tuning system, became popular.

Zenith's system used two belts --

The Robot Tuning belt is the one at lower left -- the main drive belt goes thru the chassis and onto a pulley attached to the main tuning condenser drive shaft. The lower pulley, seen under the chassis, is attached to the tuning knob.

The two dial pointers are used for coarse and fine tuning -- the tuning knob is concentric. You tune in the station approximately using the outer knob and then fine-tune with the inner knob.

 

[skyvue]

Very helpful, thanks so much! I might not have Robot Tuning, then (no buttons), but I do have the inner and outer (or upper and lower) tuning knobs.

 

[LizzieMaine]

One good thing about most of the Zeniths of this period is that the chassis is easy to work on -- the components aren't all bunched up in weird arrangements like a Philco, so if you do go in there to check the belts, you won't have much trouble figuring out how it goes.

Another thing to keep in mind is that sets of this vintage didn't have built in antennas, so to get decent reception you need to attach some sort of antenna to the screw terminal marked A or ANT on the back. Five or six feet of ordinary bell wire will get you at least local reception, and will do very well with shortwave, but if you really want the set to show what it can do, you need a good outside aerial, or at least a good amount of bare copper wire strung up in your attic.

 

[skyvue]

Actually, mine has an antenna. My buddy assumed it came with it (the radio's been in his family since the initial purchase), but perhaps it was attached at a later date. It's a thin, extendable metal antenna, not unlike those so long seen on automobiles, with a little red plastic doodad on the end of it.

 

[LizzieMaine]

That was cribbed out of a Zenith portable, possibly a Transoceanic of late-forties vintage. They would have had to couple it into the set with some kind of transformer to match the impedance, but if it works it works!

 

[skyvue]

They would have had to couple it into the set with some kind of transformer to match the impedance, but if it works it works!

I don't know if it works yet or not, since I can't really tune it, but my fingers are crossed.

Is there any benefit to doing a full upgrade of the innards, replacing all the tubes and capacitators and such? I do, of course, hope to eventually have good sound from the set, and honestly, even once I can tune it to a staion, I won't know how good the sound is/could be.