What the &*!(*!! Is a J. W. Miller 112-H6??

One of the challenges of junkbox radio construction is knowing the characteristics of the parts you've dug out of some old TV chassis or bought for a quarter at a hamfest. Sure, it says "Miller" on the side and "H-112" on the bottom, but what does that mean? What sort of coil is it? What are its essential chatacteristics?

What I'm doing here (as time allows) is scanning the vintage component data sheets that I've come across and posting them. Most of what I've scanned here came out of NOS product boxes, folded and then rolled around the component itself. That makes for wrinkled copies sometimes, but all the scans should be completely readable.

Some of the scanned sheets cover a single device. Some are more like catalog pages (which were often published in ham radio magazines) with bare-minimum specs and no physical data like hole spacing, etc. The manufacturer name comes first, followed by the device number (if the sheet covers only one device) and after that some short text to help you understand what the scanned page covers. A number of them actually have sample circuits on the back side, which can help a lot if you're doing up a design "from scratch."

I make no copyright claim of any kind to any of these scanned images. Do copy them to your own hard drive or print them out. I hope to have this site up "forever," but you never know. And if you have a scanner and some vintage data sheets that I don't have, consider scanning them and sending me an image to post. Scan them at 200 dpi, to grayscale. (The color of these sheets is almost universally...yellow.) The file size and XY dimensions aren't that important, and I can always resize or resample them if they're too big. I have plenty of room on my hosting service, and if you need the data sheet badly enough, you can request it with your browser and then go have a Coke or listen to 20 Meters for a minute or two while it comes down. I deliberately scanned them large so that there'd be no difficulty reading the text on a shrunken, fuzzified scan.

So again, take a look below, and if you have any tube-era component data sheets that I don't have, please send me a scan so I can post it here!

 

  

Other Sources for Vintage Component Data

Lindsay Books republished a 1943 Meissner book, their How To Build Instruction Manual, which is actually an early species of "advertorial" and contains a great deal of information on 40's-era Meissner coils of many types, including a lot of practical circuits and pictorial diagrams of chassis wired for the circuits. The book's ISBN is 1-55918-063-3 but is currently out of print. Watch for used copies on Amazon, eBay or ABEBooks. Another Lindsay book, the Thordarson Transformer Manual (ISBN 1-55918-243-1) is still in print and very useful in identifying and using late 1930s Thordarson power transformers, modulation transformers, and filter chokes. Lindsay has a lot of books covering tube tech, some "vintage," some brand new by the old timers who still remember this stuff from when it was first-run. Definitely request their catalog; not everything is listed on their Web site.

J. W. Miller still manufactures coils and chokes, though obviously not designed for tube work. However, they still make 2.5 mH RF chokes with wire leads. Their catalog in PDF form can be found through Mouser, here.

 

  

Links to Scanned Data Sheets

Thanks to Greg Beat for the Johnson 149 variable cap spec sheet. I'll be posting more as I find them, or as people send them to me. Whaddaya got laying around?

  

Large Scanned Vintage Data Books

Warning: The files linked to in this section are huge--up to 100 megabytes in size. It may take hours to download them even if you have a broadband Internet connection, and if you're still on dial-up, I'd recommend not even trying. Where I have the name of the originator I will credit; most of these were sent to me by third parties or found on Usenet.

  • GE Glow Lamp Manual (1965). 80 MB PDF. This is basically a high-quality photostat of GE's spiral-bound data book for neon glow lamps like the classic NE-2.
  • Meissner "How to Build" Instruction Manual (1953.) 89 MB PDF. Note that this manual is ten years newer than the reprint edition sold by Lindsay Books, and has a lot of material on FM and TV that the 1943 Lindsay edition lacks. It also includes lots of useful specs on old Meissner RF coils from the late 40's and early 50's. Again, this is a photostat (in color, yet!) and the pages are yellowed and occasionally scribbled on.
  • Raytheon Special-Purpose Tube Characteristics Manual. 8 MB PDF.Year unknown; probably mid-1950s. This is a photostat of a booklet containing specs on oddball Raytheon tubes, including (most usefully) their subminiatures, but also Thyratrons, Geiger-Muller tubes, VR tubes, and even cavity magnetrons. The scan was done by Chuck McGregor N7RHU but was sent to me by someone else.
  • RCA TT-3 Transmitting Tube Data Guide (1938). 8.6 MB PDF. Nice writeups on older power tubes, plus circuits for transmitters and other applications of power tubes.
  • UTC Transformer Catalog (1963). 25 MB PDF. Color photostat of UTC's full catalog (with specs), containing everything they had on the market in 1963.

 

  
 

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