Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dl01.r1000.mx.aol.com (Internet Inbound) with ESMTP id E5A1F38000088; Sat, 28 Jan 2012 11:08:22 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RrAoS-0000qU-8X for rs_out_1@blacksheep.org; Sat, 28 Jan 2012 16:07:36 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RrAoR-0000qL-PZ for rsgb_lf_group@blacksheep.org; Sat, 28 Jan 2012 16:07:35 +0000 Received: from mail-we0-f171.google.com ([74.125.82.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RrAoP-0005lH-Eh for rsgb_lf_group@blacksheep.org; Sat, 28 Jan 2012 16:07:35 +0000 Received: by werb14 with SMTP id b14so3482975wer.16 for ; Sat, 28 Jan 2012 08:07:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=R9DMJYIly706boiscxbN29d8MG9nT329QSzuajo4IY4=; b=w0ME9kFn6K0aD62rTM+g/RFoiafY2GkCtsfEuFBMqLIExdTIpBwbyY8EJYvNgr9LjT vEFUVHpDeyNCFicZZD2C4JJf1n5TJTU0o8T+4M1iPdeNAD5xIVyBW5cK9o1u687HDH4+ nHcrsNhNkvanJykVIXbSSWoQsVzM8fdbE0l2g= MIME-Version: 1.0 Received: by 10.216.132.88 with SMTP id n66mr4577456wei.32.1327766846752; Sat, 28 Jan 2012 08:07:26 -0800 (PST) Received: by 10.180.77.107 with HTTP; Sat, 28 Jan 2012 08:07:26 -0800 (PST) In-Reply-To: <004501ccdda3$89947f40$0401a8c0@xphd97xgq27nyf> References: <004501ccdda3$89947f40$0401a8c0@xphd97xgq27nyf> Date: Sat, 28 Jan 2012 16:07:26 +0000 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Re: OT: Headphones Content-Type: multipart/alternative; boundary=0016e6d99db03ec8d904b798cff8 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE 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-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:502426592:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m232.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d4acf4f241d7617af X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --0016e6d99db03ec8d904b798cff8 Content-Type: text/plain; charset=ISO-8859-1 Thanks Mal and everyone else for the inputs received. 73s Roger G3XBM On 28 January 2012 09:59, mal hamilton wrote: > ** > Roger > There are plenty of old ex Marine es Military headphones about that are > suitable. 2000 ohms was a common imp for the older headphones. S G BROWN > was a common make in the past plus a variety of others. Old GPO ear pieces > would also suit your requirements. > More recent communications headphones are around 600 ohms. > Old Crystal sets with a good set of high Z headphones and a decent antenna > like an inv L produced good results, plenty of volume on MF es LF > mal/g3kev > > > ----- Original Message ----- > *From:* Roger Lapthorn > *To:* rsgb_lf_group@blacksheep.org > *Sent:* Friday, January 27, 2012 10:29 PM > *Subject:* LF: OT: Headphones > > Slightly OT but people like Mal and Jim may have an answer. > > Is there a "modern" (i.e. can you buy it new today?) headphone set that is > *extremely* sensitive in the same way that the old DLR5 headsets were in > terms of efficiency converting AF to sound pressure in the ear? > > I believe Jim M0BMU claimed 2uV audio power could be heard using DLR5 > headsets in his passive mechanical SAQ receiver. As DLR5s are more > difficult to find these days I was wondering if there is anything as > sensitive, or more so, around "new". > > 73s > Roger G3XBM > > -- > http://qss2.blogspot.com/ > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > https://sites.google.com/site/sub9khz/ > > > -- http://qss2.blogspot.com/ http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk https://sites.google.com/site/sub9khz/ --0016e6d99db03ec8d904b798cff8 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks Mal and everyone else for the inputs received.

73s
Roger G= 3XBM



On 28 January 2012 09:59, ma= l hamilton <g= 3kevmal@talktalk.net> wrote:
Roger
There are plenty of old ex Marine es Military hea= dphones=20 about that are suitable. 2000 ohms was a common imp for the older headphone= s. S=20 G BROWN was a common make in the past plus a variety of others. Old GPO ear= =20 pieces would also suit=A0your requirements.=A0
More recent communications headphones are around = 600=20 ohms.
Old Crystal sets=A0with a good set of high Z head= phones=20 and a decent antenna like an inv L=A0produced good results, plenty of volum= e=20 on MF es LF
mal/g3kev
=A0
----- Original Message -----
Sent: Friday, January 27, 2012 10:2= 9=20 PM
Subject: LF: OT: Headphones

Slightly OT but people like Mal and Jim may have an answer= .=20

Is there a "modern" (i.e. can you buy it new toda= y?) headphone set=20 that is extremely sensitive in the same way that the old DLR5 head= sets=20 were in terms of efficiency converting AF to sound pressure in the ear?= =A0=20

I believe Jim M0BMU claimed 2uV audio power cou= ld be heard using DLR5=20 headsets in his passive mechanical SAQ receiver. As DLR5s are more diffic= ult=20 to find these days I was wondering if there is anything as sensitive, or = more=20 so, around "new".

73s
Roger G= 3XBM

--
http:/= /qss2.blogspot.com/
http://g3xbm-qrp.blogspot.com/
http://ww= w.g3xbm.co.uk
https:= //sites.google.com/site/sub9khz/


<= /div>



--
http://qss2.blogspot.com/
http://g3xb= m-qrp.blogspot.com/
http://www.g3xbm.co.uk
https://sites.google.com/site/sub9khz/

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