1930's Zenith

[K6JEK]

A friend plopped a big Zenith console in my garage.  "Can I fix this?"  Judging by the tubes it's from the 30's.  A schematic would be nice although I suppose I can muddle through without one.

Any advice for finding information on this beast?  The only identifying mark is a little tag on the chassis:  S859816

Jon

[Ed/KB1HYS]

That's probably the serial number. Got any photos?  I've got a Zenith console that I'm rebuilding.
If you can get the model number you'll be in good shape. 

[WQ9E]

Jon,

Nostalgia Air Resources is a great free source for schematics:  http://www.nostalgiaair.org/Resources/458/T0000458.htm

With Zenith, the same chassis was used in many models so you may need to peruse the web a bit to try and narrow things down to the correct model.

A lot of the older broadcast sets float the B- above ground to create a bias source so check this before you ground replacement filter caps directly to the chassis.  I straightened out an old Philco console for a friend who made this error.

[KM1H]

Zenith usually has a glued on label somewhere inside on the console wood.

From 1936 to 42 the model started with the tube count followed by a letter signifying the year then 3 more numbers for the actual model. One of my consoles is a 12S265 which is a 1938 12 tube shutter dial model for example.

What is the tube lineup?

Carl

[KA2DZT]

A friend plopped a big Zenith console in my garage.  "Can I fix this?"  Judging by the tubes it's from the 30's.  A schematic would be nice although I suppose I can muddle through without one.

Any advice for finding information on this beast?  The only identifying mark is a little tag on the chassis:  S859816

Jon

I use to have a complete set of Rider radio books, I think 25 binders altogether.  I left them in my shop when I sold it.  This was back in 1973.  I'm sure they're gone,  the building isn't there anymore.  I also had a complete set of the Rider TV books,  they're gone too.

So I guess my post is zero help.

You should be able to make most any common repairs without the manual.

Fred

[flintstone mop]

Zenith made some huge floor model radios during that time period, it would be nice to see some pics.

Is it like THIS

 http://www.youtube.com/watch?v=bDXDG-uoCrA

Fred

[KM1H]

I doubt if someone just "dropped off" a 1000Z.

BTW, I do have all the Riders plus many factory service docs collected during 50 years of working on this old junk on the side.

Carl

[flintstone mop]

I was hoping that the guy would be playing something other than Guy Lombardo sleeping music.
It would be nice to hear the woofers woofing and the tweeters tweet.
That was hi-fi audio and 50 watts??
Fred

[K6JEK]

There it is, the label.  I don't know how I missed it the first time.  I should be able to find the schematic now and work on the radio with an unfair advantage.

It's a rather modest radio, a lot more wood than tubes, only 8.  Here are pictures of the model, not the one I have though.  Date may be 1941

http://www.radiomuseum.org/r/zenith_8s587_ch8a03.html

Jon

[KB2WIG]

.

It's a rather modest radio, a lot more wood than tubes, only 8. 

Jon

You can't beat wood.

http://www.youtube.com/watch?v=-gwXJsWHupg




klc

[K6JEK]

Does M = K on some old schematics?

On this schematic, there are no "K's", but there are "M's" and "megohms".  What we now list as K are written out, 4700 ohms instead of 4.7K.  Some of the 'M' values seem to make more sense as kilohms than megohms.  For example, there is a B+ dropping resistor, R17, listed as 15M ohms, 1W.  It feeds a couple of screen grids.  The resistor itself measures 14.5K.  No way does a 15M resistor draw a watt at few hundred volts.

Has anyone seen M = K in other schematics?  Somewhat fuzzy scan attached.

[KM1H]

Yes, many manufacturers use M for K and Meg for M.

Is this the schematic you used?

http://www.nostalgiaair.org/Resources/460/M0025460.htm

[K6JEK]

Yes, many manufacturers use M for K and Meg for M.

Is this the schematic you used?

http://www.nostalgiaair.org/Resources/460/M0025460.htm

Thanks.  The schematic makes more sense now.  At first I thought it was a typo until I noticed more of the "M's". Yes, I'm using that schematic from nostalgia air.  I'm just starting, though, I haven't noticed yet if the schematic matches the radio.  The tubes match at least.

WQ9E:  Rodger, I meant to mention awhile back.  Sure enough, B- floats.

[Ed/KB1HYS]

That same thing threw me at first too!! Nice to know I'm not alone.  If you have Dogbone style resistors some of the high watt values are BIG.  Good luck with that project.   Ya gonna get some 78's to play on it?

[flintstone mop]

They are finally getting the scheezos to look really nice in these PDF's
Fred