1931 Cadillac Radio

[rhr1931cad]

I have a 1931 Cad radio that I am going to install in my 1931 370A AWP. anyone have recommendations on restoration of this unit. it works but you can see a resto is in order.

[Doug Houston]

Firstly, there wasn't a radio for Cadillac in 1931. There had been one in 1930, and possibly 1931 as well, but it wasn't a great success, and as a result, if you were to find one, you'd be vastly disappointed with it.

You'll need to remove the cover, which is held on with wing nuts. There will be a paper label in side the radio box somewhere, telling the model number, and will also show the tube locations in that box.

If you list the tube types, ignore the brands. They don't mean anything.

Here are the model numbers for 1932,33, and 34. They are right out of the Cadillac radio service manual.  See attached.

[rhr1931cad]

Doug, did Cadillac just put their label on this radio? Did you see the pictures. Who would have manufactured this for them?

[bcroe]

That is a great museum piece.  But radios were pretty mechanically clumsy at that time.  I
wonder if that radio was one of those needing its own dry cell batteries to operate, a huge
inconvenience?  By the end of the 30s car radios had evolved to far better equipment, in
size, performance, cost, and standardization.  A 1938 radio I have is not so different from
one made 20 years later.  Bruce Roe

[Chris Cummings]

The silver-colored box in the photos (labelled "B" Eliminator) replaced the "B" batteries that were required for the 1930-31 radio.  The "B" Eliminator was introduced in 1932. By most accounts, the 1932 radio was a pretty decent set. 

I've seen a 1931 V-12 sedan with an original installation.  It was the early radio model, and the knobs were installed by drilling holes through the instrument panel.  The "B" batteries were carried in metal boxes under the floor of the passenger compartment, between the torque tube and the frame side rail.

Doug Houston, please feel free to correct.  You know more about the old Cadillac radios than I ever will.

Chris Cummings
CLC 20072

[bcroe]

The silver-colored box in the photos (labelled "B" Eliminator) replaced the "B" batteries that were required for the 1930-31 radio.  The "B" Eliminator was introduced in 1932. By most accounts, the 1932 radio was a pretty decent set.  Chris Cummings   CLC 20072 

The B bat eliminator is a big step toward making it a practical radio.  Does that one work, the cables don't
look so good?  I didn't see any detailed info (schematics, etc) on line for it.  Bruce Roe CLC # 14630

[Wayne Womble 12210]

My `31 Sedan had a pre-installed radio antenna in the roof.  I have no reason to believe it is aftermarket. 

[Doug Houston]

There are quite a few  things in the posts above that I can answer. I'll try to get them all.

First, the 30-31 radio was designed by Delco-Remy, probably in Anderson, Indiana, where they had their HQ. The radio was made by General Motors Radio Corporation, in Dayton, Ohio. This was a very short-lived endeavor, owned by GM and RCA; each having about equal stock. It ad been formed by Kettering and RCA, from the Day-Fan radio Company, an outgrowth of the Dayton Fan Company. RCA's part in the GM Radio Corp., was kept very much under wraps, and lasted only about 2 years. During that time, they made some very good home radios and phono combinations. RCA had to pull out because of losing the case for the Superheterodyne patent monopoly. There's more to that story, but enough here.

Cadillac's name was on the radio. Cadillac had a roof antenna from 1929,

The first few years of auto radio did use battery sets, mounted in boxes that were in the floorboards of the car. Those were the "B" and "C" batteries. The "A" battery was the car battery (that's the one that lights the tubes).  Battery sets went though 1932 or so, then B-eliminators were developed, and away went the battery packs. The "B" eliminators took the form of either Genemotors, or dynamotors, as the radio business still calls them. At the same time, the vibrator powr supply came along, aat a cheaper price. They were made by a company named: Elkon. Elkon was very quickly absorbed into P.R. Mallory Corp, of Indy. Today, you will find very few of those dynamotors that don't have shorts in the armature. I always prefer to replace them with a vibrator power supply, if possible.

By 1932, the Cadillac set had proven to not cut the mustard, and 6 volt tubes were available. Cadillac cut a deal with Wells-Gardner, a high quality company, who made a lot of private brand radios (Ward's, Sears, and others, and their own name). The early Cadillac sets did use dynamotors, as late as 1936. In 1937, the dynamotors were gone, and it was purely vibrators. They actually lasted longer than most think.  Cadillac's factory sets were built by W-G from 1932 through 1939. For 1940 and later, Delco did the Cadillac sets.

In 1937, Buick had the first radio with the speaker in the dash, which almost all companies followed the next year. One of the three Cadillac sets in 1938 was a '38 Buick set, by RCA, with Cadillac control hardware.  As far as differences, the '38 automotive sets were not horribly better than the 32-33 sets, other than the use of smaller tubes. I restored a '34 Chevrolet set once, and the owner couldn't believe how well it performed. Tube technology was what enabled radio's progress.

Interesting to note here. Delco never built any radios, household, or for cars, until they bought the Crosley plant in Kokomo, Indiana. The B-O-P factory sets in the early thirties were done by General household utilities (Grunow), or later by Crosley, until Delco purchase of the Crosley plant.

Buick's sets were built by RCA from 1936 through 1942. In 1941and 42, both Buick and Chevrolet offered a 5 band radio for short wave reception. Mighty nice sets; I have one in my '41 Chevy.  Automatic (push-button) tuning began in OEM radios in 1938. Chevrolet had the honors for the first one. Delco was supplying some of the GM divisions, but not all until 1940.

Have I overstated the reply?

[Glen]

Doug,

Excellent post.  It gives us a nice history of Cadillac radios. 

[Chris Cummings]

Doug,

Thanks very much for the information and the concise presentation.  My experience with the 1941 Cadillac radio bears out your description -- a mighty nice set.  Apart from the need to wait a bit while the set "warmed up" and the fact that AM radio today is mostly talk or specialized programming, listening to such a radio is a lot of fun.  When the car was new, that radio was as "cutting edge" as an iPhone 5.

Best regards,

Chris Cummings
CLC 20072

[bcroe]

The things I would look for in an early car radio, are 6V indirectly heated tubes, a
vibrator power supply, and a superheterodyne circuit.  An RF stage really helps
the sensitivity.  Apparently the 6V tubes were '32, vibrator '37, when did the legal
stuff get sorted out for the (long since standard) superheterodyne (my '38 is)? 
Bruce (still owns MANY tubes) Roe

[Doug Houston]

RCA had the monopoly on the superhet circuit, and would never sell patent rights to anyone else. Finally, around 1930 an association, known as te Indepent Radio manufacturere took RCA to ourt to make them sell patent rights to anyone who wanted to buy them.  RCA knew that it was all over for them, and they lost the suit.

With no delay, all the radio companies had superhets on the market. They lost the suit around 1931.

[rhr1931cad]

Well All,
I have a followup to my posting of Sept 2012 about the cadillac radio. I had it restored including cosmetically to place in my 1931 Cad 370A AWP. works like a charm. I use an optima 6 volt battery mounted under the seat. a simple 14 wire for the antenna(running board antenna on order. Pulls in all am channels in the philadelphia area. The control unit mounts under the dash. A bit of skinned knuckles to get it in, but well worth it.

[bcroe]

Well All,
I have a followup to my posting of Sept 2012 about the cadillac radio. I had it restored including cosmetically to place in my 1931 Cad 370A AWP. works like a charm. I use an optima 6 volt battery mounted under the seat. a simple 14 wire for the antenna(running board antenna on order. Pulls in all am channels in the philadelphia area. The control unit mounts under the dash. A bit of skinned knuckles to get it in, but well worth it.   

Great, that radio can be kept running forever.  They work well, after the bad speakers & caps are
sorted out.  The new ones are so full of custom parts, they are disposable.  Bruce Roe