Talk:Foxhole radio

"A foxhole radio is a radio used by foxes."

That begs the question--what does the fox say? 75.9.36.166 (talk) 00:26, 28 January 2014 (UTC)

Detector

"The foxhole radio differed from the crystal radio. A razor blade and pencil were used as a diode in a foxhole radio while a piece of crystal is used as a diode in a crystal radio."

This sentence is pretty much meaningless. Both the piece of Crystal and the razor blade were used as point-contact Detectors. They both are diodes and both have the same function.

No point changing it of course as it will only be reverted.

119.18.11.19 (talk) 07:45, 20 November 2014 (UTC)

POW radios

Most POW radios were not "foxhole" radios, with a few possible exceptions during the Vietnam War. Suggest creating a POW Radio or Prison Camp Radio page and including those there.Bcarusella (talk) 17:18, 20 April 2016 (UTC)

first appearance of Fox Hole Radio Circuit

this fox hole circuit first appeared in a public magazine in 1912 (modern electrics), and was further documented in 1944 by the inventor in Radio Times, with a reference to the original publication

Not sure how a circuit could be 'invented' 30+ years after its first use

Very odd wikipedia authors are ignoring these facts

Seems to be the trend for wikipedia to remove references to facts that do not follow their narrative, or agenda

seems to be the general trend in society today, probably best not to offend the wikipedia's authors ego by proving them wrong

throws every 'fact' on wikipedia in doubt, how many other real facts are 'forgotten'

Deleting real facts and substituting your own made up facts does not change the truth — Preceding unsigned comment added by 2601:14D:300:330:ED40:DB2A:2C71:3011 (talk) 02:03, 29 August 2020 (UTC)

Hi 2601:14D:300:330:ED40:DB2A:2C71:3011, I reverted your edit. Sorry, I probably should have explained my reasons.

Hugo Gernsback, the editor of Radio-Craft who wrote the 1944 article on foxhole radios you reference, (Gernsback, Foxhole Emergency Radios, Radio-Craft, Sept 1930, p. 730) wasn't a very reliable source on the history of radio inventions. The radio detector consisting of a carbon rod resting on knife edges, which Clark Pettingill claims (Modern Electrics, Jan 1909, p.l352), to have invented was actually well known at that time. It was called a "microphone detector", because it was originally invented in 1879 by David Edward Hughes when he was developing the carbon microphone, and discovered that a carbon rod on steel points could detect electromagnetic waves.(Pierce, 1910, p.158, Sarkar, 2006, p.260) It was widely used in many forms, such as a steel needle resting across two carbon blocks,(Bishop, p.42) in early civilian and military receivers, starting around 1899.(Marriot, Proc. IEEE, p.1283, Collins, Electricity, 1905, p.89, Pickard, "How I invented the crystal detector", Electrical Experimenter, Aug 1919, p.325, Douglas "The crystal detector", IEEE Spectrum, April 1981, p.64)

The reason I reverted your edit is that the sources do not establish that the carbon-steel knife edge detector was actually used in foxhole radios. In Gernsback's 1944 article, Exhibits 1 - 3 show diagrams of foxhole radios as described by the soldiers. Notice that the carbon (either a pencil lead or a battery carbon) is shown bearing against the side of the razor blade, not the edge. The only picture of a foxhole radio we have also shows this type, with a pencil lead on a safety pin pressing against the side of the blade. This was a different type of detector, a rectifying detector. Blued steel razor blades had a semiconducting oxide coating on their sides that could rectify AM ([1]), ([2]) If you read the text carefully, it is the only type described in the primary news reports.

Exhibits 4 - 6, which showed earlier point contact detectors, were just added by Gernsback to brag that his magazine published designs of homemade detectors before the war. The 1909 carbon-steel knife edge detector as designed by Pettingill is shown in Exhibit 4. There is nothing in the article saying that it was used in foxhole radios. If it was, it would have been useless, because the "microphone" detector was a coherer detector. It was used to receive radiotelegraph stations that transmitted in Morse code, not AM voice radio stations. The edge of the razor blades did not have the coating the side did, so unless they had some kind of corrosion this detector could not rectify AM signals. Carbon-steel point detectors became obsolete with the invention of the crystal detector around 1910, 30 years before World War 2.(Marriot p.183, Robison, 1911, p.128) --Chetvorno^TALK 21:49, 29 August 2020 (UTC)

Hi Chetvorno, I agree with what you said of Gernsback's braggadocio, and that pre-WWII detectors cannot be rightly called "foxhole radios" regardless of any implied or actual continuity of design. However there is documented use of microphone style detectors during WWII, for example, one appeared in the July 1944 Field Artillery Journal. Also, the “microphone detector”, at least as popularized by Massie and Shoemaker, was not a coherer; there was nothing to cohere. A microphone can demodulate a radio signal; in fact it was the accidental discovery of the demodulation of a radio signal with a microphone detector that led to G. EW. Pickard’s research of the first practical mineral radio detectors. -- Bcarusella (talk) 14:02, 27 June 2021 (UTC)