To: rsgb_lf_group@blacksheep.org Date: Sat, 7 Jan 2006 08:01:12 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2527 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 X-Pinnacle-MailScanner-Information: Please contact the ISP for more information X-Pinnacle-MailScanner: Found to be clean X-MailScanner-From: blanch@pncl.co.uk Subject: LF: Old radio navaids Content-Type: text/html; charset=windows-1252 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-PN-SpamFiltered: by PlusNet MXCore (v2.00) Content-transfer-encoding: 8bit

Hi All,

Loran-A, post-war, was centred on 1950 and 1850 kHz. 1950 was almost entirely North Atlantic, 1850 Pacific and some American. If you heard 1850 in the UK it was genuine DX.

All Atlantic were switched off in 1980 plus or minus a bit, but the Japanese kept some going on 1850 until only a few years ago. They could be heard here in UK most winter nights.

Hifix and Hyperfix occupied numerous channels from 1650 to 2300 kHz, but was a very narrow-band system unlike Loran which was pulses. All now closed - the dreaded GPS has taken over.

The others on 133 and 144 are indeed Datatrak, a British vehicle tracking system run by Securicor but also used in some countries in Europe. A very narrow-band system

invented by a bunch of engineers who left Decca when it was bought up by Racal in the 1980's.

If you're really interested in old radio navaids read my just-published book "Air Navigation - from Balloons to Concorde" (ISBN 1-903953-90-1, Woodfield Press, £25) in which there are whole chapters on them. Yes, it's a plug (also explains why I've done very little on the ham bands for the last few years!).

Walter G3JKV.