Dennis Klipa N8ERF has been doing great work exploring the technical intricacies of the humble SWR meter (and believe me, there are intricacies). He's also been looking at the history of this invention.
This summer, Dennis and I came across the April 1964 issue of Popular Electronics. On pages 74 and 75 of that issue we found a clue that seemed to point to the origins of the device: the article referred to Naval Research Lab Report #3538 by O. Norgorden, published on September 15, 1949. This may be the paper that led to the widespread use of SWR meters by radio amateurs.
Surprisingly, this important paper was not to be found on the internet. Exhibiting an admirable dedication to the preservation of an important element of the radio art, Dennis wrote to Naval Research Lab and purchased from them a copy of the report. Unfortunately, the version Dennis got had been copied and recopied so many times that it was hard to read. So he went the extra mile and re-typed it.
With his permission, I am giving this article its internet debut by posting it here:
http://soldersmoke.com/SWR N8ERF.pdf
Three cheers for Dennis Klipa for unearthing this important piece of radio history.
Re: Help to ID Modulation Iron
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For some reason, looks a bit 'Thermador-ish' to me. No nameplate will be a
challenge.
3 hours ago