HIFIX Personal Reminiscences

I was contacted recently by Eduard Van Bergen, who wrote this about his time working with Decca:

"I am an old Deccaman and operated the various Hi-Fix, Hi-Fix-6 and Hyperfix chains in Holland, England, Denmark and Helgoland in the 70's and 80's. I started in 1969 for Decca England and then I went over to Decca Survey Services Holland. We had our own sea-going ships at the time - Decca Explorer, (We brought that one later to a scrapyard in Holland, interesting thing about that ship was that it was a former " U-boot 'versorgungsshiff " that roamed the Atlantic ocean in search for German submarines to supply them with fuel and food in the second worldwar named " Meer Katze ", the other ship was the Decca Mariner who came into the harbour in Scheveningen (Holland) around Christmas time to give us a nice meal around that time. she is still sailing under a different name in Nigeria now.

"What I remember from all those long years on the respective Master and slave stations gives me a good feeling. Things were somewhat primitive in those days, but that was also the charm of it, and yes, when something kicked the bucket and you had to repair it, it was either at nighttime or in a blazing storm, apart from the regular maintenance of course. Very steady patterns with no lane-slips when the landpath was stable due to soaked soil because of rain and very unstable with static or hail or snow, the equipment went crazy then. We transmitted here on 1934 and 2154 kHz and when you were for some reason out of the air you had to restart and synchronize the LF and HF MDU,s on the 100ms triggerpulse manualy with a synchro-cord, something that you did by listening to the sound of the relays. 100ms Master triggerpulse and 300ms Masterpulse, 300ms Slave 1 and 300ms slave 2. This all was for the Hi-Fix III.

"There were days that you took fixes with the English and Dutch navy, one every minute, you wrote down the readings on the Pattern counters and APC on the Master station and they did the same onboard their vessels, that way you could compare the measurements together and in a way calibrate the hyperbolic system. For those purposes we used the Pye-Single Side Band tx/rx, the same we used for communications between our stations. I still remember the command ; " Stand by . . . . Fix " The trick was always to tune the tx unit besides the tx aerial for maximum output so it could withstand the night-static and sky-wave. We had to make a weather/technical report every hour " between dawn and dusk " as it was called and phone in the results each morning to the head-office by mobile-phone. We were mainly housed in (first small and later large) caravans and once a Master station was off the air due to the fact that the caravan was blown over on its roof, injuring the operator inside and disconnecting the pwr cables in one go. When it was heavely storming you were always sitting/sleeping near the side of the caravan that was jumping up in the wind to make it a bit more heavy with your own weight, in the winter the water freezed and sometimes your gas as well.

"Yes, it was primitive, but I would not have missed it for the world ! Writing all this down, I do'nt think that the young people of today have any thoughts about how that pioneer-time was. You just switch on your gps or dgps these days and that's it! Well, to cut a long story short, after Decca I worked for Racal and after that R.E.E and Thomson (France)and Thales and now I work for a Denish company called 'Reson'. Many things change in our lives."

Roger Basford G3VKM was an engineer working for Decca from 1969 until 1973. He wrote:

"I certainly used HIFIX in a portable mode. The stations were designed to allow one man erection and operation, including putting up the antenna. A typical portable set-up of the kind I used frequently for Royal Navy chains was comprised of a long-wheel-base Land Rover, towing a standard 3-4 berth caravan. In addition to chain equipment, all the domestic kit for one or two man operation was carried plus a couple of single-cylinder diesel generators. Sometimes the gennys would be left behind if a mains supply could be used. For other jobs in less hospitable spots the stations were made to be road, boat or air-transportable, I put at least two stations up in Mozambique using only one of the little Bell Whirlybird helicopters (as seen in "MASH"!) with gear tied onto the landing skids. Stations were often landed from boats, I did this in Malaysia and the Scottish Hebrides. The worse part of this type of landing was lugging the 6 volt batteries for the station ashore!

My first job with HIFIX was in Java, Indonesia; we had a contract with the World Health Organisation and the agrochemical company CIBA to provide track-guidance to crop-spraying aircraft dusting the rice crop with chemicals to kill moth larvae that ate the rice stems. I spent six months there in 1969 and had my 20th birthday there. The job was unique in that we didn't have carefully surveyed locations for the stations, it was more a case of driving around until a clear patch of dry paddy field was found or some other suitable spot with a clear take-off over the spray area. Often we would use a village football pitch after paying a suitable bounty to persuade the village team to play away for a few days. These stations were often set up before dawn and taken down at night and moved to the next spray area. On two occasions I operated from the slopes of active volcanoes (at up to 9000ft ASL) one of which erupted a few days after we moved! We also had a high turn-over of spray pilots as there were three crashes in my six months with three deaths, I witnessed one in which two flight engineers on an air-test "augured-in" on the airfield where I was setting up the ground to air VHF set for the day's operations. There was one survivor of the three people in the aircraft, a local helper who had fancied a flip.

The permanent chains for N. Sea operations began to be set-up in the late 1960s/early 1970s when N. Sea oil took off. There was a UK network from Walcott in Norfolk to Sumburgh Head at the south end of Shetland. I can remember a few locations but I was never employed on those sites, I was purely a sea-going HIFIX "engineer", a job which meant you spent a lot of time in your bunk, unless you had a surveyor who was prepared to let a mere engineer touch the gear and help with the operation. I'm sure HIFIX engineers will remember the joys of "lane-counts" and dropping "reference buoys" to maintain the ship's position! I'll try to make up a list of East Coast sites and let you have them in due course.

There was a short-lived spin-off from HIFIX called SeaFix, it was designed to be put into moored buoys at sea - not sure if it ever worked. After HIFIX and it's derivatives Decca moved onto Pulse/8, a spin off of LORAN which operated on 100kHz and several of the old HIFIX sites were re-used for that system with bigger masts. Pulse/8 went in the mid-90s, I think, after the GPS constellation became fully operational 24/7. We dabbled with the US Navy "Transit" satellite system in the 1970s and 1980s. Transit had to wait for a decent number of passes before giving an accurate position but it was useful for final drill-rig locations or surveying-in land beacon positions without the need for a land survey team. The early Transit gear for a rig-move took up a whole Sea King chopper!

A rival to HIFIX was Hydrotrac, developed in the US by Odom Offshore Surveys of Baton Rouge, La. and also built under licence (and operated) by Gardline Surveys in the UK. Hydrotrac was an all solid-state system and the first system I ever used that employed CMOS chips. I was trained at Odom and helped set up the first stations to cover the N. Sea, including one on Fair Is. HYDROTRAC was developed further and renamed HYTRAC but I didn't get involved in that, having left Gardline before the re-launch. There were a number of other systems around, notably ARGO which was also a Top Band system that used pulse techniques and other short-range microwave and UHF systems like Trisponder, Miniranger and Cubic Autotape, all American in origin. SHORAN, the short range version of LORAN, was around too and developed into MAXIRAN which was even dirtier on-air than Syledis and was never licensed in the UK, as far as I know. I moved on from Gardline and ran a Syledis chain covering the Dover Strait for four years (1982-86) whilst the cross-channel power cables were being laid, not a popular job for a radio ham due to the appalling signals Syledis put out on 70cm. Eventually, that system was scuppered by the MOD who didn't like their MOULD system being jammed. HYPERFIX lived on into the 90s in Norway and I believe a lot of the N. Sea stations were kept on for a while at the request of some NATO navies, it was all gone by the end of the 1990's though. Hyperfix ATUs still turn up on eBay and at rallies, selling for big bucks due to their vacuum tuning capacitors.

Ian Jackson, G3OHX sent me a number of emails containing his recollection of a HIFIX site in Seahouses, Northumberland:

"Bloody awful things they were (at least the one at Seahouses was). It was on 1901kHz, and there were key clicks all over the 160m band- even 10 miles away. As they used a time-shared RF phase comparison, the keying waveform could have been very soft indeed. I wrote to the RSGB to try and get them to complain, but that was in the days when it was a real gentleman's club, and I was fobbed off with the statement that we were secondary users on 160m, and although Hifix was also secondary, were more secondary still!

They did have an interesting antenna. It was a 30' vertical, with four top hat radial / guy wires coming nearly down to ground level, and lots of relatively short ground radials beneath it. I copied the idea, and the antenna works well. It puts out a good groundwave (which it is supposed to do), but is useless for inter-G working on skywave.

The original mast was maybe 35 to 40 foot max (and not 30'). I think it was simply 1.5" ali tube.

There were two sets of four guys. The first were at about 20' (and surprisingly didn't seem to be insulated from the mast). The second were at the top, connected to the mast. These were the capacity hat. All eight guys were insulated at about 2' from the ground.

The whole thing was like a pyramid, surrounded by a fence.

At the bottom of the mast was essentially a large dog kennel, which housed the TX/RX. Originally, there was a generator, but later they ran in a mains power line in a trench from the road (about 200 away). A caravan also appeared, which parked beside the compound (I think, rather than inside). I remember going inside to have the 'eyeball' QSO with G3VZV. There was a helical whip on the roof (and an HF transceiver of some sort inside).

There were lots of ground radials which reached the fence. I seem to recall that some were later extended outside, where the public could trip over them!

I well remember the 'waltz' rhythm of the chain on 1901, resembling a 'J' in morse. The initial trigger 'dit' was (I believe) 60Hz lower than the three 'dahs' (from the three slave stations). Many an SSB QSO went on zero beat with the dahs! I think that the power was 40W to a miniature 807 (QQVO xxx).

There were other 'fixing' transmissions on 160m. The French had some which were several CW carriers which were not quite on the same frequency. Again, the fixing was done by measuring the phase differences between them (somehow).

In those days there was a permanent Loran station on 1950kHz (from Benbeccula -sp? - in the Outer Hebrides). This made 1920 to 1980 essentially unusable at night. There was also a Loran slave station (1950 again) at Newton-by-the-Sea (Northumberland). This was on only rarely (I think when they were having NATO exercises in the North Sea). It could be heard as an image in the middle of the MW band However, I did 'win' a Raynet contest on 160m one Sunday operating /M from just off the beach at Boulmer (just a few miles down the coast, of course). Long before the days of Japanese talk-boxes on 2m and 70cm!

Happy days!"

Alf, GW3SRG, told me about the chain covering Swansea Bay:

"The hifix near me was located, near enuf, 51:34:05 N, 003:58:55 W, on Mumbles Head. It was one of 3 covering Swansea Bay, the other 2 were on Jersey Marine (coast road between Swansea and Port Talbot) and Port Talbot. It operated on 1900 kHz, maybe a coupla kHz lower. From memory, the mast looked like a 15 foot 2" dia pole with a ceramic base."