Hi everyone

I am researching Hifix and Hyperfix positioning systems for a web site
project. These were specified to operate in the band 1.6-3.4 Mc/s but were
probably most familiar to UK SWL's as the 'jingle bells' that used to be on
their two main allocations around 1810 kc/s and 2100 kc/s. Chains of
transmitter sites were located around the coast and provided precision
(compared to, say, Decca) position fixes over short ranges, and were used by
oceanographic surveyors and the oil industry. Hifix was launched by the
Decca company in 1964, but was phased out in 1983 when it was replaced by
Hyperfix. This fell out of use when GPS became the only way to rock and roll
and the UK sites were decommissioned between 1995 and 2000. During this
time, ownership had passed from Decca to Racal.

What I need is any technical details that you might have about the
Hifix/Hyperfix systems; their history, specification, principles of
operation, transmitters, receivers, transmission format. Do you know where
any sites were located in the UK? In fact, anything at all really. Perhaps
you worked on the system as a technician or as a user?

My email address is alancordwellATblueyonderDOTcoDOTuk. Note the antispam!!

Many thanks and best regards, Alan.