Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,RCVD_IN_DNSWL_MED, SPF_PASS,SUBJ_ALL_CAPS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: EATSERVER: mailn 1166; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v2GAgAgb013290 for ; Thu, 16 Mar 2017 11:42:11 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1coSk8-0001nP-6B for rs_out_1@blacksheep.org; Thu, 16 Mar 2017 10:34:52 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1coSk7-0001nG-Pj for rsgb_lf_group@blacksheep.org; Thu, 16 Mar 2017 10:34:51 +0000 Received: from mail-wr0-x236.google.com ([2a00:1450:400c:c0c::236]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1coSk5-0006pM-1E for rsgb_lf_group@blacksheep.org; Thu, 16 Mar 2017 10:34:50 +0000 Received: by mail-wr0-x236.google.com with SMTP id u48so28762983wrc.0 for ; Thu, 16 Mar 2017 03:34:48 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:message-id:mime-version:subject:date:references:to:in-reply-to; bh=4Lp6Grzm6z4IGpHrr0CBLoBYfKHN+F/JjMSyqueicoo=; b=ntV+2XnlPv9+bpvpiT5gTa94naG42VZ3NfCwnytZwpnd6RFx9NDaTlE6/DiVPkK4pk G3exA9fVcWVJey2EJZ5+hkCA6acGTy30sHnz/2uV2AhfBq/wq9E7hJSd+oMwsedpGJ9+ G/OqULZt2U96NK4m4H5MGeko+omRdxCf5mCNFLHeVM0ZKUEJbqJAtXM63lq2SdLMldAv W6uaIkdO96xlIuMas8VRkIhBZu0Vb5h3eU5OQRs2+yGNXHnZq3ry5RTVVMN0Qf0iROE2 QM/hys2DfNStJKUZG5UH+HKkspBQBhV+2sMTfETQ61aumKuv9cZ9giD9mekhHuTNvs0B 51+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:message-id:mime-version:subject:date :references:to:in-reply-to; bh=4Lp6Grzm6z4IGpHrr0CBLoBYfKHN+F/JjMSyqueicoo=; b=B2+/4OE/4fEAbRo90RiVNMQEntMJbrVvmYaF+ziRVFnehhwIQl5jX9tUUMx5u9cmAR O2omMWEVEAA0wshlTZsovogEISLZLg5hqc4tkwJyrIqv6wITbpfIoAy2gmOWvkhFhFl0 0z178C8Pf+Op8HJ6W0eK4W7sexNGeGJyGgcBHXOihduMqwePx3eO8HZD4N47QnqNc/xk qqW6rR7lX42h/SE8176/HjzjXyF6o4Yr/ETdmcTW2X5DQJXFmBC5gzaazRjae/psSWys LrlEEL7lZAm9NDvyAYKatqkY8jZrjG28Ck4XzbncSVUqJBEZFj1B2YDwqfS8qw0Hz8UF fYlw== X-Gm-Message-State: AFeK/H3SVWUaEzOLSalTLrz9nlWtZXsgGgCi8CQVhDT/LE70C98yq7HYQNykwEu3v2S4oQ== X-Received: by 10.223.153.39 with SMTP id x36mr7481669wrb.64.1489660488132; Thu, 16 Mar 2017 03:34:48 -0700 (PDT) Received: from [192.168.1.101] ([82.98.23.94]) by smtp.gmail.com with ESMTPSA id b199sm3798122wmb.13.2017.03.16.03.34.46 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 16 Mar 2017 03:34:47 -0700 (PDT) From: John Rabson Message-Id: <853D8B1B-1793-45B8-BBA2-59EE775F0810@gmail.com> Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Date: Thu, 16 Mar 2017 11:34:44 +0100 References: To: rsgb_lf_group@blacksheep.org In-Reply-To: X-Mailer: Apple Mail (2.3124) X-Scan-Signature: 982d53dbb4bb82e9ed4f38562b2a1556 Content-Type: multipart/alternative; boundary="Apple-Mail=_0184D492-C597-40D9-B952-0B533B7E85B2" Subject: Re: LF: M0BMU? 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-Scanned-By: MIMEDefang 2.75 Status: RO X-Status: X-Keywords: X-UID: 10909 --Apple-Mail=_0184D492-C597-40D9-B952-0B533B7E85B2 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Roger, The most recent email I can find from Jim was sent to the RSGB group on = 4 April 2013 and related to Rubidium Frequency Standards. It read as = follows: > Dear Ken, [I don=E2=80=99t know who Ken was] >=20 > Provided your RX is set to receive the R4 carrier frequency, it does = not=20 > matter what the frequency display shows - all that matters is the = difference=20 > between the R4 carrier displayed on the spectrogram, and the nominally=20= > 198kHz harmonic of the 1kHz signal obtatined from dividing the 1MHz = output=20 > of the counter. Frequency errors in the RX will cause an offset in the=20= > spectrogram frequencies, but it will be the same offset for both the = off-air=20 > signal and the reference signal. >=20 > For example, suppose you set your RX to 197kHz USB, and look at the=20 > spectrogram around 1kHz - you might see the R4 carrier at 1005Hz. This = 5Hz=20 > offset will probably mostly be due to the RX; possibly also a = contribution=20 > from sound-card sampling rate error. If you now introduce the divided=20= > reference signal, you might see a second trace appear at 1005.1Hz, = which=20 > would show that your local frequency standard was +0.1Hz above the = nominal=20 > 198kHz, about +0.5ppm frequency error. >=20 > A small amount of RX drift does not matter much - the traces will move=20= > around a bit on the spectrogram screen, but the frequency difference = between=20 > them will not be affected. However, rapid drift may smear out the = traces, or=20 > cause them to dissapear off the screen completely. >=20 > Cheers, Jim Moritz > 73 de M0BMU Last year I was preparing an article for CREGJ about the radio station = at SAQ and emailed Jim with a view to using details of is = electromechanical receiver but I did not receive a reply. 73 John F5VLF john.rabson07@gmail.com Researching history of RABSON, BLACKSHAW, GAUNTLETT, VERLANDER and = ROBSONNE --Apple-Mail=_0184D492-C597-40D9-B952-0B533B7E85B2 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Roger,

The = most recent email I can find from Jim was sent to the RSGB group on 4 = April 2013 and related to Rubidium Frequency Standards. It read as = follows:

Dear Ken, [I don=E2=80=99t know who Ken = was]

Provided your RX is set to = receive the R4 carrier frequency, it does not 
matter = what the frequency display shows - all that matters is the = difference 
between the R4 carrier displayed on the = spectrogram, and the nominally 
198kHz harmonic of = the 1kHz signal obtatined from dividing the 1MHz output 
of the counter. Frequency errors in the RX will cause an = offset in the 
spectrogram frequencies, but it will = be the same offset for both the off-air 
signal and = the reference signal.

For example, suppose = you set your RX to 197kHz USB, and look at the 
spectrogram around 1kHz - you might see the R4 carrier at = 1005Hz. This 5Hz 
offset will probably mostly be due = to the RX; possibly also a contribution 
from = sound-card sampling rate error. If you now introduce the = divided 
reference signal, you might see a second = trace appear at 1005.1Hz, which 
would show that your = local frequency standard was +0.1Hz above the nominal 
198kHz, about +0.5ppm frequency error.

A small amount of RX drift does not matter much - the traces = will move 
around a bit on the spectrogram screen, = but the frequency difference between 
them will not = be affected. However, rapid drift may smear out the traces, or 
cause them to dissapear off the screen completely.

Cheers, Jim Moritz
73 de = M0BMU

Last year I was = preparing an article for CREGJ about the radio station at SAQ and = emailed Jim with a view to using details of is electromechanical = receiver but I did not receive a reply.

73 John F5VLF

john.rabson07@gmail.com

Researching history of RABSON, BLACKSHAW, GAUNTLETT, = VERLANDER and ROBSONNE




= --Apple-Mail=_0184D492-C597-40D9-B952-0B533B7E85B2--