Elmer G. Osterhoudt
Modern Radio Laboratories

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Modern Radio Laboratories® missing documents and literature

You can find MRL handbooks and copies of "Radio Builder and Hobbyist" at AmericanRadioHistory.com
MRL Datasheets, handbooks and some "Radio Builder and Hobbyist" can be found on the Internet Archive

1963 MRL Catalog
This catalog was shared in April 2022 by Jeff Schmidt of Washington, DC.

In February of 2021, the two MRL documents below were found in a binder in an antique store by Mike Jones, KD9CNV. The binder was filled with MRL publications and schematic diagrams. Mike scanned them and donated them to this site. RB&H No. 34 is rare. Elmer lost all his unsold copies in 1959 while relocating in Redwood City, CA.

The binder once belonged to James D. Blyth, 940 Belmont Ave, Chicago, IL. Obviously a fellow fan of MRL!
  MRL Radio Builder No. 25   RB&H No. 34  

In 2019, the MRL documents below became available after a fellow fan of MRL named Northe Osbrink donated scans of them to this website.

  RB&H No. 35 RB&H No. 36 RB&H No. 38  

Download, read, and enjoy these priceless MRL publications.

Note: These copies may appear "light." There are several reasons for this. First, either the ink has faded or some of the text was gray instead of black. Second, the paper he used is thin. A scan of a page shows what is on the reverse side coming through. The paper has also turned a beige color. Scanner settings were adjusted to produce the best copy possible.

In April of 2020, more MRL documents (previously) lost to history surfaced, thanks to crystal set fan Mark Everhart. Mark offered to scan these publications and donate them to the site. His only motivation was to share them with the rest of us.
  RB&H No. 37 RB&H No. 39 RB&H No. 40  
  Detail Print No. 32
No. 5 Double Crystal Set
Detail print No. 37
Crystal Set Amplifier
Detail print No. 42
AC Oscillator
  Detail Print No. 51
No. 23 Combination DX Set
Detail Print No. 55
No. 24 DX Regenerative Set
Detail Print No. 60
Two Stage T.R.F. Amplifier

In May of 2020, our friend Sloane Freeman scanned these documents. They were found in a binder that was labeled "1964."
  Detail Print No. 34
No. 10 All wave Crystal Set
Detail Print No. 38
Six Watt Class B Power Amp
Detail Print No. 45
No. 22 DX Marvel Crystal Set
  Detail Print No. 46
# 30 DX Crystal Set
Detail Print No. 50
No. 21 Local Selective Crystal Set
Detail Print No. 52
No. 13 Variable Selectivity
  Detail print No. 53
No. 27 Variable Selectivity
Detail Print No. 54
No. 34 Wired Wireless System
Detail Print No. 62
No. 6 Capacity-Coupled Crystal
  Detail Print No. 65
No. 17 Pinole Special
Detail Print No. 66
No. 20 Variable Selectivity
Detail print No. 67
No. 25 Selective Crystal Set
  Detail Print No. 76
Operator's Code Chart
Old Detail Print Index

More MRL documents
  Radio Flyer No. 1
2 Pages.
Radio Flyer No. 3
10 pages.
Radio Flyer No. 6
8 Pages
  Radio Flyer No. 15 (1962)
8 Pages
Radio Flyer No. 23
11 Pages
1972 Catalog cover page
Cover pages usually don't survive.
    Detail Print No. 43
No. 26 All Wave Set (old version) *
* DP-43 describes the No. 26 Single Dial All Wave Crystal Set. It is marked "Rev June, 1963." This older Version of DP-43
   describes the "All Wave Crystal Set" but it employs a vacuum tube! Thanks to Sloane Freeman for the document.

Alva Allen Radio
This advertisement was placed by one of Elmer's Competitors, Alva F. Allen. Allen had been selling "Melomite Crystals" with instructions on how to build your own radio since 1932, the year MRL began.

Click on the add to see what you got for 25¢

The Star Toy Maker
                           THE STAR TOY MAKER

Elmer wrote that he read this book in 1912. From plans in this book he and his brother Cyril made motors, bird houses, a talking machine, electric bells, stilts, sleds, etc. Their father made the kaleidoscope in the book using mirrors and a lathe. This is described in Radio Datasheets Vol 6.

Click on the book to read it.

Note: it's a small book in .PDF format. The text is so small it is easier to read the .PDF version than the actual book.

If you want to print a copy use this.

Another MRL Mystery! This ad is from the October 1936 issue of Modern Mechanix. It states you get a year's subscription to "Setbuilders Data." Was "Setbuilders Data" a publication? Was it actually "Radio Builder?"

We are actively searching for high quality scans of the "missing" MRL documents. 
Please send email to mike@mikesyard.com   <cut>mike@mikesyard.com<paste>
A list of the "known" missing literature follows. Some of it is over 90 years old. This list keeps getting shorter and shorter!!
MRL Oscillator

MRL Blue prints

MRL Radio Flyer
2, 4, 5, 7 to 14 and 16 to 22 (if they exist.)

MRL Radio Builder
Issues 1 to 33.

MRL Catalogs prior to 1963

MRL Detail Prints. The following are missing. The ones with no description may not even exist.
DP-3 MRL No. 38 Crystal Booster
DP-5 No Description Available
DP-7 MRL No. 40 Crystal Set
DP-8 MRL No. 41 Crystal Set
DP-9 MRL No. 42 Crystal Set
DP-10 MRL No. 43 Crystal Set
DP-15 No Description Available
DP-17 No Description Available
DP-20 No Description Available
DP-40 No Description Available
DP-68 No Description Available
DP-70 No Description Available
DP-71 No Description Available
DP-72 No Description Available

A photo of an MRL plug-in coil with the colored band on the top painted on.

A scan of Page 4 of HB-4 "
MRL 1-TUBE D.C. ALL WAVE RECEIVER," with the tube type missing, or the tube type  stamped on the page.

A photo or just the part number of a 4.3 volt mercury battery supplied with the MRL No. 10. A search for a picture of any 4.3 volt battery by any manufacturer has so far been fruitless.

Also desired are photographs of MRL kits and items sold by MRL.

Do you have any of these, and would you like to share them with the rest of us "old timers" and crystal set fans? Please email mike@mikesyard.com Thank you.

Elmer Osterhoudt Stamp Collection
MRL stamp collecting
  Feb 1938 ad in Short Wave Craft   1952 Radio Builder and Hobbyist No. 34  
We have no information whatsoever on Elmer's stamp collecting or as a sideline to MRL. Any information would be welcome.


I would like to extend a sincere "thank you" to Don Knotts of Hillsboro, Oregon for sending the coils, documents and unassembled kits that were passed down to him from his father. 

Thanks also to tack, Peter Bertini, Number 6, mrx, wazz, Bugman, and radiohenry of the Antique Radio Forum,
especially Number 6 (whose real name is Ernest Allen), who supplied Mabel's passport application, the date the Osterhoudt's were married, and arranged for the photo of the Osterhoudt's grave marker to be taken.

Thanks to Sloane Freeman who supplied valuable information about EO not found in his publications, as well as 14 "missing" Detail Prints, and photos of his No. 2, No. 18 and No. 26 MRL sets.

Thanks to Tom Philo for the picture of Elmer from the 1918 Compton HS yearbook. He obtained it at my request from
the City of Compton Collection, Gerth Archives and Special Collections, California State University, Dominguez Hills.
The entire yearbook page is here.

Thanks to Victor Rodriguez for obtaining photos of Elmer, high school yearbooks, the name of the church where Elmer and Mabel were married, newspaper articles, census records, and many other details.
Also, thanks to Gary Schneider (RIP 03/12/20) who somehow, some way, still had MRL coils available on his website.
Thanks to Northe Osbrink for supplying the 1973 MRL catalog and Radio Builder and Hobbyist 35, 36 and 38
Thanks to Mark Everhart for supplying RB&H 37, 39 and 40, as well as half a dozen Detail Prints.
Thanks to Michael Jay Jones for supplying Radio Builder No. 25 and No. 34.
Thanks to Doug Wilson for various pictures, including the MRL Antenna Eliminator and MRL 1 Tube and No.2 XTAL sets.
Thanks to Lois E. Ray of the Scotts Mills Historical Society.
Thanks to Laverne Osterhoudt.
Thanks to Dave Osterhoudt.
Thanks to Don Holdaway for a snapshot of his MRL No. 26
Thanks to Pete Steinmeyer for contributing over a dozen MRL handbooks and other publications.
Thanks to Donna Olson, daughter of Wilda Osterhoudt.
Thanks to the Bob Rydzewski of the Society of Wireless Pioneers for supplying Elmer's application form.
Thanks to Jeff Schmidt for the 1963 MRL catalog and Radio Flyer No. 15.
Thanks to Quentin Schiltz for his photos of his 1938 MRL No.2 crystal set.
Thanks to Drew Matlovsky at the Oregon State Archives
Oh yeah, thanks to Scott of "Scotts Crystal Radios," who doesn't know I stole his picture of the MRL No. 2
Crystal Set. He's where you get your headphones for your crystal radios. His website is here.

Thank you also to our Australian friend Graeme Zimmer, who provided the list of MRL publications shown on Page 6 and the photos of the MRL Carborundum crystal. Graeme also uploaded all of the MRL documents found on worldradiohistory.com.

Thanks to Jim Kearman, who investigated Elmer Osterhoudt's copyrights and found that they were owned by Elmer, not by his company, Modern Radio Laboratories®. Since Elmer left no heirs, the copyrights would have gone to his next of kin, who are also deceased. In any case, publications copyrighted between 1923 and 1977 expired after 28 years. Elmer's last copyright expired around 1998.

MRL literature can be found online thanks to Graeme Zimmer at AmericanRadioHistory.com.

Thanks to Paul Nelson for keeping MRL alive into the 21st Century.