Return-Path: Received: from rly-md02.mx.aol.com (rly-md02.mail.aol.com [172.20.29.140]) by air-md02.mail.aol.com (v121_r4.4) with ESMTP id MAILINMD022-8eb4963f07f333; Tue, 06 Jan 2009 19:00:17 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-md02.mx.aol.com (v121_r4.4) with ESMTP id MAILRELAYINMD023-8eb4963f07f333; Tue, 06 Jan 2009 19:00:04 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1LKLpl-0008AF-9z for rs_out_1@blacksheep.org; Tue, 06 Jan 2009 23:59:41 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1LKLpk-0008A6-Lc for rsgb_lf_group@blacksheep.org; Tue, 06 Jan 2009 23:59:40 +0000 Received: from web28103.mail.ukl.yahoo.com ([217.146.182.123]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1LKLpk-0005Wk-Fv for rsgb_lf_group@blacksheep.org; Tue, 06 Jan 2009 23:59:40 +0000 Received: (qmail 59472 invoked by uid 60001); 6 Jan 2009 23:59:34 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.co.uk; h=X-YMail-OSG:Received:X-Mailer:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type:Message-ID; b=3RUMAex66TZ9ZcyfjjTnN8XoZDp4Dj1DIDgzBJDjnVJs1RqCyLvQ8jJWacvYrO+u8BL3m0h1bJrDMN1yCZh8mC7PrQstF9K8FpFGg8VlPS4M5XT1jVLZyqSLNirPhYvV0wWserwnyB/4B7Anq1/WD9Uy7alX2M2yJvnpVV+/NCE=; X-YMail-OSG: vMa40F8VM1nM.PoDQhKGy5WHx0b6bDPAV5JwqEKqqq.iZkktgc1ZkRbMoywvAD6LldYNHI97T5TgfDohRUTfBYY0PGuAmyBGgkpBvfttFOYSrrA1Kmj3GCJgrrk8XVxbyidOuanJxFDPmB2JbSSPmoxI5otR8G4_oepvymSXRf1bm6UkqNwC8LiBP8.WvC4Q66TrhWbWmn0nbQ-- Received: from [86.130.69.9] by web28103.mail.ukl.yahoo.com via HTTP; Tue, 06 Jan 2009 23:59:34 GMT X-Mailer: YahooMailWebService/0.7.260.1 Date: Tue, 6 Jan 2009 23:59:34 +0000 (GMT) From: M0FMT To: rsgb_lf_group@blacksheep.org In-Reply-To: <1LKLYw-0Bsx4S0@fwd08.t-online.de> MIME-Version: 1.0 Message-ID: <621531.58485.qm@web28103.mail.ukl.yahoo.com> X-Karma: 0: DomainKey-Status: good (testing) Subject: Re: LF: Razor blade RX .... Try a Cohere? Content-Type: multipart/alternative; boundary="0-900494556-1231286374=:58485" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.2 required=5.0 tests=CLICK_BELOW,HTML_30_40, HTML_FONT_FACE_BAD,HTML_LINK_CLICK_HERE,HTML_MESSAGE, HTML_TAG_EXISTS_TBODY autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-AOL-IP: 193.82.116.20 --0-900494556-1231286374=:58485 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi Hajo and LF =C2=A0 But you still have the issue of Hi Impedance headphones. A Coherer allows yo= u to switch a light or buzzer on and off. They are amazing in free state the= y have a very high DC resistance (virtually open circuit)=C2=A0and once they= cohere it is virtually a dead short. But may be not as sensitive as a rusty= nail detector!=20 =C2=A0 There is a report of UK to Gibraltar using a 2.5kW Sparker on 350m and the R= X being a Coherer. Not bad for Mechanical Radio! =C2=A0 73 petefmt=C2=A0 --- On Tue, 6/1/09, hajo.brandt.dj1zb@t-online.de wrote: From: hajo.brandt.dj1zb@t-online.de Subject: Re: LF: Razor blade RX .... Try a Cohere? To: rsgb_lf_group@blacksheep.org Date: Tuesday, 6 January, 2009, 11:42 PM =C2=A0No problem! Use MCW! Has been typical for 500 kHz. 73 DJ1ZB =C2=A0"M0FMT" schrieb:=20 Hi Mal and LF =C2=A0 I am disapointed in you Mal to be=C2=A0considering an envelope detector. A t= rue CW man, I would have thought,=C2=A0should only entertain the use of a Co= here detector! =C2=A0 Having played with them, I was surprised how well they work over a range 136= kc/s to 433mc/s (the extent of my power RF O/P) probably work over a much la= ger range of frequencies but not tested by me. =C2=A0 http://home.earthlink.net/~lenyr/coherer.htm =C2=A0 73 pefmt =C2=A0 --- On Tue, 6/1/09, mal hamilton wrote: From: mal hamilton Subject: Re: LF: Razor blade RX To: rsgb_lf_group@blacksheep.org Date: Tuesday, 6 January, 2009, 9:21 PM Your own cct and ideas and the headphone construction. Not info from the web= . g3kev =C2=A0 ----- Original Message -----=20 From: riese-k3djc@juno.com=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Tuesday, January 06, 2009 7:58 PM Subject: Re: LF: Razor blade RX 310113517964=C2=A0=C2=A0 E bay too =C2=A0 On Tue, 6 Jan 2009 18:00:45 -0000 "mal hamilton" wri= tes: Since I mentioned a Razor blade and fence wire RX a while back I have had se= veral requests for a circuit. To give=C2=A0others the opportunity=C2=A0to su= bmit a cct I will await replies. This method=C2=A0was used successfully =C2= =A0at Coldiz=C2=A0and other POW camps to receive BBC broadcasts. Let us know how you would approach the subject. This is applicable to MF/LF=20= since the broadcasts at the time were receicved on these bands. Build one and have a QSO using this RX g3kev =C2=A0 =C2=A0 ____________________________________________________________=20 Fashion Design Education - Click Here! No virus found in this incoming message. Checked by AVG - http://www.avg.com=20 Version: 8.0.176 / Virus Database: 270.10.3/1877 - Release Date: 1/5/2009 7:= 20 PM =C2=A0=20 =20 --0-900494556-1231286374=:58485 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Hi Hajo and LF
 
But you still have the issue of Hi Impedance headphones. A Coherer allo= ws you to switch a light or buzzer on and off. They are amazing in free stat= e they have a very high DC resistance (virtually open circuit) and once= they cohere it is virtually a dead short. But may be not as sensitive as a=20= rusty nail detector!
 
There is a report of UK to Gibraltar using a 2.5kW Sparker= on 350m and the RX being a Coherer. Not bad for Mechanical Radio!
 
73 petefmt 

--- On Tue, 6/1/09, hajo.brandt.dj1zb@t-onli= ne.de <hajo.brandt.dj1zb@t-online.de> wrote:
From: hajo.brandt.dj1zb@t-online.de <hajo.brandt.dj1= zb@t-online.de>
Subject: Re: LF: Razor blade RX .... Try a Cohere?
= To: rsgb_lf_group@blacksheep.org
Date: Tuesday, 6 January, 2009, 11:42 PM=

 No problem! Use MCW! Has been typical for 500 kHz= .

73 DJ1ZB


 "M0FMT" <m0fmt@yahoo.co.uk>=20= schrieb:=20
<= /TR>
Hi Mal and LF
 
I am disapointed in you Mal to be considering an envelope detector= . A true CW man, I would have thought, should only entertain the use of= a Cohere detector!
 
Having played with them, I was surprised how well they work over a rang= e 136kc/s to 433mc/s (the extent of my power RF O/P) probably work over a mu= ch lager range of frequencies but not tested by me.
 
 
73 pefmt


 


--- On Tue, 6/1/09, mal hamilton <g3kevmal@talktalk.ne= t> wrote:
From: mal hamilton <g3kevmal@talktalk.net>
Sub= ject: Re: LF: Razor blade RX
To: rsgb_lf_group@blacksheep.org
Date: Tu= esday, 6 January, 2009, 9:21 PM

Your own cct and ideas and the headphone co= nstruction. Not info from the web.
g3kev
 
----- Original Message -----
Sent: Tuesday, January 06, 2009 7:58=20= PM
Subject: Re: LF: Razor blade RX

310113517964   E bay too
 
On Tue, 6 Jan 2009 18:00:45 -0000 "mal hamilton" <g3kevmal@talktalk.net<= /A>> writes:
Since I mentioned a Razor blade and fence w= ire RX a while back I have had several requests for a circuit. To give = others the opportunity to submit a cct I will await replies. This metho= d was used successfully  at Coldiz and other POW camps to rec= eive BBC broadcasts.
Let us know how you would approach the subj= ect. This is applicable to MF/LF since the broadcasts at the time were recei= cved on these bands.
Build one and have a QSO using this RX
g3kev
 
 


= ____________________________________________________________
Fashion Design Educat= ion - Click Here!

No virus found in this incoming message.
Checked by AVG -=20= http://www.avg.com
Version: 8.0.176 / Virus Database: 270.10.3/1877 - Re= lease Date: 1/5/2009 7:20 PM

 

=20 --0-900494556-1231286374=:58485--