[ARC5] ARC5 Digest, Vol 267, Issue 11

Mon Apr 6 10:48:53 EDT 2026

There is a Excellent PDF of Crystal Clear by Richard J. Thompson.  

https://oceanofpdf.com/authors/richard-j-thompson-jr/pdf-crystal-clear-the-struggle-for-reliable-communications-technology-in-world-war-ii-download/ <https://oceanofpdf.com/authors/richard-j-thompson-jr/pdf-crystal-clear-the-struggle-for-reliable-communications-technology-in-world-war-ii-download/>

Complete book with List of Manufactures.

I have it loaded on my iPad.  It is 5.4 MB.  254 pages.

Verne
W6LPM

> On Apr 5, 2026, at 5:19 PM, arc5-request at mailman.qth.net wrote:
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> Today's Topics:
> 
>   1. Re: Wartime FT-243 xtal mfrs (Mike Feher)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Sun, 5 Apr 2026 20:18:57 -0400
> From: "Mike Feher" <n4fs at eozinc.com>
> To: <scottjohnson1 at cox.net>, "'Doran Platt'" <jeepp at comcast.net>,
> 	"'ARC-5 Mail List'" <arc5 at mailman.qth.net>
> Subject: Re: [ARC5] Wartime FT-243 xtal mfrs
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset="utf-8"
> 
> Scott- 
> 
> 
> 
> I of course have a copy as he visited me in 80?s to take pictures of some of my crystal sets. I just took a look, and found one on Amazon, https://www.amazon.com/Crystal-Clear-American-Detectors-Crystals/dp/0911572961 . 73 ? Mike 
> 
> 
> 
> Mike B. Feher, N4FS
> 
> 89 Arnold Blvd.
> 
> Howell NJ 07731
> 
> 908-902-3831
> 
> 
> 
> From: scottjohnson1 at cox.net <scottjohnson1 at cox.net> 
> Sent: Sunday, April 5, 2026 7:06 PM
> To: 'Mike Feher' <n4fs at eozinc.com>; 'Doran Platt' <jeepp at comcast.net>; 'ARC-5 Mail List' <arc5 at mailman.qth.net>
> Subject: RE: [ARC5] Wartime FT-243 xtal mfrs
> 
> 
> 
> I have looked for this book for years but have yet to find a copy.
> 
> 
> 
> Scott W7SVJ
> 
> 
> 
> From: arc5-bounces at mailman.qth.net <arc5-bounces at mailman.qth.net> On Behalf Of Mike Feher via ARC5
> Sent: Friday, April 3, 2026 6:00 PM
> To: 'Doran Platt' <jeepp at comcast.net>; 'ARC-5 Mail List' <arc5 at mailman.qth.net>
> Subject: Re: [ARC5] Wartime FT-243 xtal mfrs
> 
> 
> 
> Not to be confused by the same titled book by Maurice Sievers which is about Antique Crystal Radios. 73 - 
> 
> 
> 
> Mike B. Feher, N4FS
> 
> 89 Arnold Blvd.
> 
> Howell NJ 07731
> 
> 908-902-3831
> 
> 
> 
> From: arc5-bounces at mailman.qth.net <mailto:arc5-bounces at mailman.qth.net>  <arc5-bounces at mailman.qth.net <mailto:arc5-bounces at mailman.qth.net> > On Behalf Of Doran Platt via ARC5
> Sent: Friday, April 3, 2026 8:20 PM
> To: ARC-5 Mail List <arc5 at mailman.qth.net <mailto:arc5 at mailman.qth.net> >
> Subject: Re: [ARC5] Wartime FT-243 xtal mfrs
> 
> 
> 
> The best historical tome for crystals is the book "Crystal Clear".  It lists over 50 wartime crystal providers.  It goes over the Brazil Connection, Leo Meyerson, and a whole lot more.  
> 
> Jeep K3HVG 
> 
> On 04/03/2026 7:46 PM EDT hwhall--- via ARC5 <arc5 at mailman.qth.net <mailto:arc5 at mailman.qth.net> > wrote: 
> 
> 
> 
> 
> 
> Resurrecting an old thread.  But I'm fascinated by crystals. Lemme grab some popcorn! I think AF4K's old website had a list (incomplete) of manufacturers. 
> 
> 
> 
> https://af4k-crystals.com/RadioCrystals-Holders-Companies-History.htm#companies 
> 
> 
> 
> Wayne 
> 
> WB4OGM 
> 
> 
> 
> On Friday, April 3, 2026 at 05:11:52 PM MDT, Richard Knoppow via ARC5 <arc5 at mailman.qth.net <mailto:arc5 at mailman.qth.net> > wrote: 
> 
> 
> 
>    I don't know if there is a list of companies but there is certainly 
> 
> a lot of historical material out there. Making good crystals was black 
> 
> magic until it was discovered that synthetic crystals could be made. 
> 
> Most crystal material came from Brazil and was difficult to get during 
> 
> war time. A great many crystals turned out to be defective. It was then 
> 
> discovered the bad ones could be crushed up and new, synthetic crystals 
> 
> grown, which were nearly perfect. Other discoveries were etching and 
> 
> plating. At the beginning of WW-2 making crystals was a sort of 
> 
> specialized cottage industry. There had been a relatively small market, 
> 
> which exploded with the requirements of the war. 
> 
>    Let me see what is in my files and if I can find on-line sources. 
> 
>    It is an interesting subject, somewhat akin to the discovery of how 
> 
> to make optical glass (mostly by Bausch & Lomb)  and how to coat lenses. 
> 
> 
> 
> On 7/30/2023 6:28 PM, Paul Thekan wrote: 
> 
> I recently obtained a box of close to 800 or more FT 243 xtals ,haven't 
> 
> counted them all yet, and was going through them looking for any useful 
> 
> freqs on the ham bands and noticed how many different companies were 
> 
> making xtals during the war. So far I've identified at least 45 
> 
> companies making these xtals. 
> 
>   Is there any info out there that talks about how many companies were 
> 
> involved in making these xtals. 
> 
> Thanks 
> 
> Paul 
> 
> N6FEG 
> 
> 
> 
> 
> 
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> -- 
> 
> Richard Knoppow 
> 
> Los Angeles 
> 
> WB6KBL 
> 
> SKCC 19998 
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> End of ARC5 Digest, Vol 267, Issue 11
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