Elmer G. Osterhoudt
The Modern Radio Laboratories Catalog 

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The very first Modern Radio Laboratories advertisement.
Submitted to Short Wave Craft in 1932, it appeared in the February 1933 issue.
The address is the location of the Manchester Radio Electric Shop, Elmer's radio store.

Elmer stated that at the time he placed this advertisement he knew of no other crystal set ad. It was a gamble that apparently paid off. For 25 you got a "Blue print" of a crystal set, not the actual crystal set. For the same 25 you had already obtained the copy of Short Wave Craft, which was filled with radio diagrams.

25 in 1932 had the buying power of $4.40 in the year 2020.

In the beginning, MRL didn't carry any crystal radio parts. Elmer had been making and selling hundreds of plug-in coils, but these weren't designed for crystal radios. Apparently, the very first (and only) MRL mail-order product that wasn't a plug-in coil was the blue print for the MRL No.1 Crystal Set.

In HB-17 "MRL 20 Crystal Set Circuits," the first circuit is the MRL No.1 Crystal Set. Under the diagram Elmer wrote, "This is the set that started us in the mail order business."
The MRL No.1 DX Crystal Set, circa 1932. Recreated set built in 2020.

Early Advertisements

Advertisement in the May, 1933 issue of Short Wave Craft.

Note:  MRL Detail Print No. 63, Two Tube All Wave DX Receiver, seems to be an update to the Blueprint advertised above. It is the only 2-Tube MRL circuit found that picks up shortwave and uses vacuum tubes available in 1933. Unfortunately, it is not a copy of the Blueprint. According to Radio Builder # 25, DP-63 was revised on November 1, 1946.
              Click on the icon to the right to view DP-63.

MRL ad from Radio magazine June, 1933.

MRL ad from Radio Craft magazine, also from June, 1933. You now get Blueprints for six more crystal sets.

The last MRL ad with the 23rd Avenue address appeared a month later. By this time the Great Depression had wiped out thousands of banks, and the unemployment rate was at 20%. The Manchester Radio Electric Shop seems to have closed, another victim of the economy.

MRL ad from Radio Craft magazine, November, 1933. This same ad appeared in the January 1934 edition of Short Wave Craft but the word TUBELESS was added to CRYSTAL SET. This would have cost Elmer 10 for the extra word but he omitted the name of the state to compensate. See similar ad below.

The new address was the location of Mabel's parents house, which had been converted into two apartments. Apparently, Elmer and Mabel lived there for five years during the Great Depression.

MRL ad from Radio World magazine March 10, 1934. The ad now boasts "1800 miles." By 1938 the distance was 4250 miles. However, these extreme reception reports were made using a No.2 set, which picked up shortwave. 4250 miles is the distance between Lansing, MI and Berlin.

From Radio Craft March 1944. The distance is now 5300 miles. The received transmission may have been "Radio Moscow" on a No. 2 set. The distance between Kansas City, Kansas and Moscow is 5300 miles. Notice the address is barely readable.

From Radio Craft June 1944. Elmer may have designated the 'X' to track which issue was generating sales, since the March issue had a smeared address. There were no other MRL ads in Radio Craft for 1944 or 1945. The next ad appeared in the November 1946 issue.


The first radio plans sold by MRL were for the No.1 Crystal Set, described in Hand Book 17 and Detail Print 26. However, the greatest legacy of MRL is probably the No.2 Crystal Set, which Elmer "invented" in 1932 and eventually sold as a kit. Oddly, the catalog entry for the No. 2 Crystal Set is just a footnote at the bottom of page K-1, shown above.

Catalog page K-1 is an entire page devoted to the MRL No. 2-A single dial set. Elmer states that both sets have been made and improved upon since 1933.

At the bottom of the catalog page it states that HB-2 (or Hand Book 2) "MRL No.2 Long Distance Crystal Set" is 50 extra. It has a copyright date of 1945. In the back of HB-2 there are five pages of testimonials in a closely typed small font. Elmer claimed to have hundreds of reports in a stack six inches think.

Later, he published Detail Print 22, "MRL No. 2 LONG DISTANCE CRYSTAL SET". In this DP Elmer wrote that the size of the stack of testimonials was then 12 inches thick. The date of DP-22 is not known, but it was included in the MRL DETAIL PRINT FILE, dated 1958.

The stack must have at least doubled again by the time of his death in 1987.
This is the top of Detail Print number 22. In typical Elmer Osterhoudt fashion, the drawings are made face on or a side view without the slightest angle. The drawings in HB-2 are the same; squares, circles and lines.

An MRL No. 2 Long Distance Crystal Set.
MRL No. 2 front panel.
The drawing suddenly comes to life once you know what you are looking at!
The front panel is 5 1/2" by 7". The radio was not sold with a base.

This No. 2 was built into a plywood box.
This radio was built by a Bob Dildine of Santa Rosa, California in the early 1970s. He did a nice job on the radio and on the box. The bottom and sides of the box are kerfed so everything slides together without fasteners or glue. You just slide the bottom off and both the radio and back panel slide out.

Because it was housed in the box it is pretty much pristine inside.

Coil connections to the switch taps.

MRL No. 2
Another MRL No. 2, also in a wooden box. This was built in 1977 by Sloane Freeman.

Another MRL No. 2. These are getting rare. Only three have appeared on ebay in the last few years.

Want to see something REALLY rare?


An unbuilt MRL No. 2 Long Distance Crystal Set from 1980.
The switch points, front and rear. The panel is actually jet black but doesn't come out well in photographs due to the finish.
The variable capacitors came wrapped in this paper.
The back and front of the panel where you attach the variable capacitors. Everything is countersunk. Elmer called the panel material "compo." There are many references to compo panels in his handbooks. It's probably short for "composition board." I've often wondered if the compo panels are Masonite.
The screws are inserted into the capacitor, the shaft has been cut, a wire joins both sections. There is a big honking solder lug on the capacitor body. This is how Elmer sent both capacitors.
The coil, hand made by Elmer. If he had hundreds of testimonials about this set in 1945, how many of these coils did he make?
Many MRL sets use those brightly colored pin jacks on the left. They came in white, yellow, orange, red, and blue. Despite these parts being 40 years old, they still look new. The brass on the MRL switches is still shiny.

Now let's think about this set for a minute. Elmer made the coil form, then wound the coil on the form. He cut out the "compo" panel, then drilled the holes, countersunk them and painted the panel. Then he riveted the switch points onto the panel.

He made the two MRL switches. He printed the dial scales. He prepped the variable capacitors, then he added two knobs, a knocked down crystal detector, a mounted crystal which he made himself, two pin jacks, two Fahnestock clips, hookup wire, and solder. He put the crystal, cat whisker, and dial scales in envelopes, which were printed on the outside with what was inside the envelopes.

He had to purchase the material to make the coil form. He bought the variable capacitors, crystal stand, knobs, headphone jacks, parts to make the switches, rivets, solder lugs, screws, wire, solder, paint, envelopes, etc. Then he hand printed a copy of Detail Print #22, which he authored himself.

Elmer sold this kit for $7.50 in 1980. That's equivalent to $25.00 in 2020. MRL (under Paul Nelson) sold the same kit in 2020 for $92.85! In 2020, the price of the variable capacitors alone exceeded $25. Unfortunately it was "Temporarily Out of Stock" for years, and was removed from the MRL website in 2021.

Handbook Number 2 or HB-2, copyright 1945. It is 24 pages printed in a tiny font in a pamphlet about 9.5 x 6.5 inches. This HB is a different size than all the others. All of Elmer's handbooks were lithographed by Elmer, except HB-2, which was printed on a printing press. The print is actually pressed into the paper, as shown above on the right.

On page 9, Elmer references an article in the February 1934 issue of Radio magazine, so even though the copyright date is 1945, it may have evolved from an earlier publication, possibly the "blueprint" he sold in the 1930s.

The last original copy of HB-2 was sold sometime in 1983. A customer of MRL named Sloane Freeman related this story in June of 2020:
"In 1983 I put in an order for some things over the phone, among them a HB-2 handbook. Elmer told me he was totally out of them and would not be printing any more. This was a couple of weeks after Mabel died. Five or six months later an envelope comes in the mail and there is my HB-2. Elmer had found one copy in a stack of stuff and remembered I wanted one. So unless he found some more somewhere, mine is the last."

Paul Nelson printed a batch of duplicates in 2003 on Elmer's lithograph machine. They are available today on the MRL website.


Here's a nice MRL No.2 from the 1990's.
The switches and crystal detector were made by Paul Nelson.


In 1938 and 1939 the address for Modern Radio Labs was 7700 East 14th Street in Oakland, CA. From 1940 to 1943 the address was 1406 77th Avenue, both of which are in this building at the corner of 14th and 77th. The entrance to 1406 77th Avenue is behind the pickup truck and utility pole. The storefront faces 14th Street. The actual address of the building (in the year 2018) is 7700 International Blvd.
1939 Oakland Yellow Pages ad.
Why did the MRL address change in 1940? The 1940 US Census shows they did indeed have a radio store here. Perhaps the Osterhoudt's just switched the MRL mailing address for convenience. Maybe the days of the radio store were coming to an end. A lack of inventory during the rationing of WWII would have put them nearly out of business, anyway. In 1942, consumer radio production was halted by the US government, as was nearly every other appliance.
1940 phonebook entry. 7700 E 14th was the storefront.
1940 and '41 entry, but the phone number is not the same as the MRL number in 1939.
1941 phonebook entry. The store is no longer listed, but Elmer is a salesman.
There is no listing in the 1940 or 1941 Yellow Pages for the store name or either address.

According to an article by Dick Mackiewicz in Radio Age magazine, during WWII Elmer was an instructor for wartime radio technicians and operators. His draft card shows that in 1942 he was employed by the US Navy at the US Naval Air Base in Alameda, CA. If this was the case, the shop may have been closed for the duration, and never reopened.

Modern Radio Labs did carry on during the war, as evidenced by a 1943 advertisements in Radio World and Popular Mechanics. However, an ad in the March 1944 edition of Radio Craft has the MRL address in Hayward, CA, so the Osterhoudt's had moved out of this building by then. Hayward is about 10 miles south of Alameda.
1406 77th Avenue entrance. Above the mailbox next to the door can be seen the address (right-hand photo.)
The building is a "2-Story Mixed Use Commercial/Residential situated on a 3556 Square Foot Lot". The street level section is zoned "Commercial - Retail/Office". Upstairs is zoned "Urban Residential" and is a "4 bedroom/2bath Residential..." It was built in 1923.
According to the 1940 census, Elmer and Mabel Osterhoudt owned this property, lived here and operated a radio store.
This is how it looked 80 years later, in 2020.

2610 18th Ave San Francisco, CA
A year after the Osterhoudt's moved to Hayward, they moved to San Francisco, to this house at 2610 18th Avenue. According to ads placed in Popular Science, they were here from May to December 1945. A note on Elmer's draft card says they had actually moved out by November 1945 to San Carlos, California. The house above was built in 1931.
In late 1945 the Osterhoudt's moved to this house in San Carlos, CA. and lived here until 1950.