Elmer G. Osterhoudt
The Modern Radio Laboratories Catalog 

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Catalog entry for the MRL 1 Tube DX radio.
Click on picture for the full catalog page.
In 1940 Elmer developed the MRL 1 Tube regen radio. The circuit is a typical regen but Elmer claimed he perfected the layout of the parts. He made a six page mimeographed "blueprint" named BP-2 which described the radio. After selling thousands of these the stencils disintegrated.

In 1954 he published HB-4, "MRL 1-TUBE D.C. ALL WAVE RECEIVER." The handbook describes every aspect of the radio and how to make every part of it. All data is included for making the plug-in coils.
Elmer wasted no time in advertising the new handbook. This is an ad in "Radio and Television News."
Why gather all the parts and make the coils when you can just buy the kit from MRL? The kit came with two coils for the AM broadcast band but you had to buy the tube separately. Most tubes were $1. If you didn't want to build the kit, Elmer would build it for you for $3.

At the time HB-4 was published, the price was $6.50.
The first 1000 copies of the handbook had the tube type omitted. After some inquiries by customers, Elmer made a rubber stamp and stamped the remaining copies. The later printings included the stamped tube type, but he changed the value of C-5 from .0001 to .00048. This change was written in ink.

If you have a copy of HB-4 with no tube type listed on page 4, or a copy with the type stamped onto the page, it is quite a collectors edition (but nobody knows it).

Oddly, this circuit was obsolete by the time Elmer made the handbook and kit. As a matter of fact, the manufacture of this type of radio had been banned sometime before 1924. One tubers (sometimes called "Bloopers") can oscillate through the antenna and wreak havoc with other radios.

So why did Elmer create this kit in 1940? This is purely conjecture, but 1930s radio magazines had many advertisements for one tube radio kits. By 1940 the ads had practically disappeared. That would make competition for MRL's one tube set almost non-existent.

The MRL 1 Tube radio works well, but requires patience to tune. Like a crystal set, it needs a set of high impedance headphones, also available from MRL.
Other MRL 1 Tube examples are here

Here you can see one of the changes made during the years. When Elmer could no longer obtain 140 pF variable capacitors, he used a trimmer in series with a 350 pF cap. Notice the trimmer on the left is also shown in the drawing at the top of the page.

Later, he obtained two-section capacitors. He added an MRL-made switch to switch one of the sections in or out. The switch is closed for the AM broadcast band and open for shortwave.

An unassembled MRL 1 Tube kit from 1980.
  MRL antenna tune capacitor. MRL switch.  
"Compo." base with parts mounted by Elmer Osterhoudt.

If this kit is ever assembled, the coil socket will need to be moved to the top of the base because the leads are too long.
Elmer (or Mabel) wrapped the front panel in waxed paper. Something has gone through the paper and scratched the panel. No worries; in the instructions Elmer says to sand it and paint it.


Photo Thanks to Graeme Zimmer. Click for larger version.
Sorry, no photo of the assembled kit. You'll have to assemble it in your mind, like Nikola Tesla would do.
A picture of the completed front panel of a No.18 set can be seen on Page 5.

  In the May / June 1979 issue of "The Mother Earth News," Copthorne MacDonald wrote an article on crystal sets and listed MRL as a source for parts, and more specifically, the MRL No.2 Crystal Set.

In a letter dated July 12, 1979, Elmer wrote that because of the article, he sent out over 500 catalogs. He said he had never sold so many crystal sets. Apparently some people wanted the assembled kit, and he still had 19 sets waiting to be wired up.

It is interesting to see that the address for MRL begins with "DEPT TMEN." Of course, that would be short for The Mother Earth News, so EO seems to have been consulted before the article was published.

Elmer was 80 years old at the time.

                             Click on the article to open a readable version



In 1970 Elmer and Mabel moved to 2612 Butano Drive, Sacramento, CA
It seems that all of the Osterhoudt residences were one story with a garage. MRL was in the garage.