Return-Path: X-Spam-DCC: paranoid 1102; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_30_40,HTML_MESSAGE autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tASIg8MW029295 for ; Sat, 28 Nov 2015 19:42:08 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a2kOe-0005ZY-Do for rs_out_1@blacksheep.org; Sat, 28 Nov 2015 18:38:56 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a2kOd-0005ZP-Tv for rsgb_lf_group@blacksheep.org; Sat, 28 Nov 2015 18:38:55 +0000 Received: from mail-wm0-f43.google.com ([74.125.82.43]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1a2kNb-0000RR-SQ for rsgb_lf_group@blacksheep.org; Sat, 28 Nov 2015 18:38:54 +0000 Received: by wmec201 with SMTP id c201so105566509wme.0 for ; Sat, 28 Nov 2015 10:37:35 -0800 (PST) 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=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=kgS4bGSAVCAAgO2WdpRtAglLB17Jh27BOl1e7iEL1vw=; b=ZrPhde+43idsVx4RkBWvTm7Enw3zG8HbqWFNGuk81FKeVhvqmUyeBBI0rS1ufzJAJc NIu6CTkJf+jjyHh01ka2Thi4KbN7kybv1iBx5KoZIzdIAIdI30dTrpjjWXFNPgw8pVhU vPBdxxPeA1wnAb0lphJ5KlfwG6Adi9e9SBI1Db7hXTtfISiZhJPjgy2yCZrbXCo4AShI TIC7EW8M0icpUj41w8UGsA6IojxfNXtSQWz4+4uFdASIwheYfvHOS8NlPbbeW8Ln8qbi NYbWBOdzSzN5kGZ//oMZEaiIqz/p0GUdIXFBrDYiDYvJcmTCA7t94lkKthfB6b0G/nMQ HRHQ== MIME-Version: 1.0 X-Received: by 10.194.87.170 with SMTP id az10mr8141586wjb.144.1448735855003; Sat, 28 Nov 2015 10:37:35 -0800 (PST) Received: by 10.28.130.139 with HTTP; Sat, 28 Nov 2015 10:37:34 -0800 (PST) In-Reply-To: <8D2F817FF3F663B-12B8-15ABE9@webmail-vm090.sysops.aol.com> References: <8D2F817FF3F663B-12B8-15ABE9@webmail-vm090.sysops.aol.com> Date: Sat, 28 Nov 2015 18:37:34 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: b42857a5fad6e32377447282c21f62b1 Subject: Re: 3 phase (was LF: G3KEV) Content-Type: multipart/alternative; boundary=089e010d867c02d2cc05259e1ac9 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 2.56 on 10.1.3.10 Status: RO X-Status: X-Keywords: X-UID: 5397 --089e010d867c02d2cc05259e1ac9 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Back in my student days, I once spent time at a place that did final tests on a missile launcher system that had 400Hz motors. One test was phase rotation of the supply. The chap in charge didn't like the long winded test procedure proscribed (I don't know what it was, he never used it) so he'd made himself a network in a tobacco tin (yes, truly) using CR phase shifter network and neon bulbs. It worked easily and quickly, lighting one neon or the other depending on rotation 'jnt On 28 November 2015 at 17:18, Markus Vester wrote: > I've been wondering if there exists a screwdriver-like handheld voltage > tester which can identify a 3-phase sequence, without physical connection > to the "other" phases. Using an internal crystal reference, such a devic= e > could measure line frequency and phase while touching the first point, an= d > then remember the phase state while being taken to the next one. Dependin= g > on line frequency drift rate you may have to be quick, but I think it cou= ld > be practical. > > Best 73, > Markus (DF6NM) > > > -----Urspr=C3=BCngliche Mitteilung----- > Von: Andy Talbot > An: rsgb_lf_group > Verschickt: Sa, 28 Nov 2015 5:29 pm > Betreff: Re: 3 phase (was LF: G3KEV) > > What's wrong with that ? > Sounds an excellent idea for a QRO transmitter. 300Hz ripple - much > easier to filter out. > > My 137kHz Tx runs from rectified (single phase) mains - the isolation is > provided in the ferrite output transformer and FET drive pot-core > > A school we once went around with long leads and an AVO identifying > sockets to be found on all three of the phases. That was so that, using > extension leads, we could bring them all into the lab to get a three phas= e > motor running. Such interesting things could be done in schools in the > 1970's > > Andy G4JNT > > > On 28 November 2015 at 15:52, John Rabson wrote= : > > > In the early days of 73 kHz I believe a Luxembourg station built a > transmitter which was powered off full-wave rectified three-phase mains > without an isolating transformer. NOT the best way of doing things! > > John F5VLF > > --089e010d867c02d2cc05259e1ac9 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Back in my student days, I once spent time at a place that= did final tests on a missile launcher system that had 400Hz motors. =C2=A0= One test was phase rotation of the supply.=C2=A0 The chap in charge didn&#= 39;t like the long winded test procedure proscribed (I don't know what = it was, he never used it) =C2=A0so he'd made himself a network in a tob= acco tin (yes, truly) using CR phase shifter network and neon bulbs.
It worked easily and quickly, lighting one neon or the other d= epending on rotation

'jnt

=

On 28 Novem= ber 2015 at 17:18, Markus Vester <markusvester@aol.com> w= rote:
I've been wondering if there exists a screwdriver= -like handheld voltage tester=C2=A0which can identify=C2=A0a 3-phase sequen= ce, without=C2=A0physical connection to the "other" phases.=C2=A0= Using an internal crystal reference,=C2=A0such a device could measure line= frequency and phase while touching the first point, and then remember the = phase=C2=A0state while being taken=C2=A0to the next one.=C2=A0Depending on = line frequency drift rate you may=C2=A0have to be quick, but I think it cou= ld be practical.=C2=A0
=C2=A0
Best 73,
Markus=C2=A0=C2=A0(DF6NM)
=C2=A0

-----Urspr=C3=BCngliche Mitteilung-----
Von: Andy Talbot <andy.g4jnt@gmail.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 28 Nov 2015 5:29 pm
Betreff: Re: 3 phase (was LF: G3KEV)

=20
=20
What's wrong with that ?
Sounds an excellent idea for a QRO transmitter. =C2=A0 300Hz ripple - = much easier to filter out.

My 137kHz Tx runs from rectified (single phase) mains - the isolation = is provided in the ferrite output transformer and FET drive pot-core

A school we once went around with long leads and an AVO =C2=A0identify= ing sockets to be found on all three of the phases.=C2=A0 That was so that,= using extension leads, we could bring them all into the lab to get a three= phase motor running. =C2=A0 Such interesting things could be done in schoo= ls in the 1970's

Andy G4JNT


On 28 November 2015 at 15:52, John Rabson <john.rabson07@gmail.= com> wrote:

In the early days of 73 kHz I believe a Luxembourg station built a transmi= tter which was powered off full-wave rectified three-phase mains without an= isolating transformer. NOT the best way of doing things!

John F5VLF

--089e010d867c02d2cc05259e1ac9--