[Milsurplus] Foxhole Radio - conclusion

[W2HX]

Responding to this old post. When I was a kid, my father showed me a fox hole radio diagram that I built. It used a safety pin opened up that touched not a blue blade, but a regular "safety" razor. However, the razor had to be left out in the weather for a week or two because it had to be rusty.  The safety pin touched the rusty part and worked like a charm into a very high impedance earphone. Picked up both stations! (also in long island, NY). Later I hooked up my father's bogen amplifier to the circuit and bona fide audio! (didn't they have bogens in the trenches?!)

 
73 Eugene W2HX
 

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Al Klase
Sent: Monday, August 06, 2012 1:36 PM
To: milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] Foxhole Radio - conclusion

Mike,

Yes, I have.  Overall, this detector is not very sensitive, get something going with a germanium diode, so you know you're in the ballpark.  One of the tricks is to scratch part way through the bluing on the blade.  Some suggest there is selenium, a semiconductor material, involved in the coating.  There is, of course, carbon, another semiconductor, involved in both the pencil lead and the high-carbon steel.  I've had success with the hardened edge of other, non-blue, blades.

There's potentially useful info on my site here: 
http://www.skywaves.ar88.net/xtal/xtal.htm

I highly recommend the PGXS circuit if you're going to wind a coil.

Build a crystal set.  It's good for your soul,

Al

On 8/6/2012 11:58 AM, mstangelo at comcast.net wrote:
> Has anyone ever tried building one of these foxhole radios?
>
> I started my journey inot electronics, like may others, by building crystal radios.
>
> I got my crystals from a neighbor who was an electronic technician . 
> My first crystal was in a bakelite case. I forget the number but I still have it somewhere. The tapped coil was built on a schellaced toilet paper roll. My headset was a high impedance crystal earpiece.
>
> I lived in Queens New York at the time and could easily pick up WCBS 880.
>
> I read about the foxhole radio which used a Gillette Blueblade and the pencil graphite as a detector. The graphite was held with a safety pin.
> I got hold of the blade and graphite and tried it but could never get it to work.
>
> Has anyone hasd success with this type of detector? If I could get my hands on a Blueblade I'd try it again.
>
> Mike N2MS
>
>
> ----- Original Message -----
> From: Hue Miller<kargo_cult at msn.com>
> To: milsurplus at mailman.qth.net, tetrode at googlegroups.com, 
> Wireless-Set-No19 at yahoogroups.com
> Sent: Sun, 05 Aug 2012 22:54:12 -0000 (UTC)
> Subject: Re: [Milsurplus] Foxhole Radio - conclusion
>
> The opinion was also expressed that soldiers have often have time on 
> their
>
> hands, where boredom is an issue: thus, they would relish some 
> activity
>
> like the opportunity to build 'foxhole radios'.
>
> <snip>
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--
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/

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