Personal Reminiscences of Hyperfix
Why am I so interested in HiFix/Hyperfix?Being a frequent visitor to the North Yorkshire coast near to Whitby, I had the opportunity to study the characteristics of two of these stations,on the North Yorkshire coast near to Whitby The first of these was near to Highgate Howe, and consisted of a 30m triangular lattice mast guyed with three sets of three guys. The equipment acommodation was a wooden garden shed at the foot of the mast. The whole site was easily accessible via the road which leads to Whitby lighthouse. I studied the signal characteristics and was surprised to find that the site actually radiated on two frequencies: 1809 and 2157 kc/s. The transmission was a 2-second pattern of CW pulses which continuously repeated. No other type of transmission ws observed. The pulse patterns on each of the two frequencies were different, on 1809 kc/s it a group of 2 followed by a single pulse (bip-bip, bip) whilst on 2157kc/s there was just a single pulse. the width of each pulse was probably around 100mS. The antenna height estimate is supported by calculation for a quarter wave vertical from the formula h=234/f (Mc/s) feet which gives 117 ft at 2 Mc/s; allowing for the velocity factor.
OS Grid Ref: NZ924102
Antenna type: Guyed triangular lattice tower, about 100ft height.
Transmission frequencies: 1809 and 2157kc/s
Current State:
Highgate Howe site went off the air sometime in late 1994. In May 1995 the transmitter hut was removed, leaving the mast and the concrete pad where the hut stood. By July 1995 these had gone too. The only evidence still in existance is a BT telegraph pole carrying overhead to a corner of the plot, which carries a label with the circuit number and the word 'RACAL'. This pole is visible in the photo below.
Pictures: I never photographed the site with antenna and hut. The two pictures below are identical images of the plot of land where the site once stood. On the left hand picture I've very carefully drawn in the mast and shed, and even if I say it myself, it looks a lot like I remember it to be. The land to the left of the picture slopes down toward the clifftops- if you climbed up to where the fence is, you'd see the sea.
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The other site I found in an slightly more unorthodox manner. While doing the work on the Highgate Howe site, I noticed strong transmissions in the same format on 1807kc/s. The signal strength suggested a fairly local source, however other than the site described above, there were no obvious other masts. I constructed a directional loop antenna and connected this to my Sony ICF2001D, this allowed me to take rough bearings. Using 3 well spaced receiving sites, after some initial debugging and calibration work I got a pretty good 'cocked hat' on an area of the coast some 2 km SE of Highgate Howe. But there was still nothing to see- at least from a distance. Now the OS map shows a footpath running from the village of High Hawsker to join the coast path near to a farm called Gnipe Howe. I decided to take the 2001D and walk this path while monitoring the signal. As I approached the farmhouse, the signal came up colossally in strength, but it wasn't until I could see around the back of it i.e. the side facing the sea that the source was finally revealed! This consisted of a short tubular pole- I estimated 30 feet - guyed with a single set of guys, standing on a doughnut insulator about 9in diameter. The shed was more like a dog kennel in size, and the whole thing looked more temporary than permanent to me, it was also heavily overgrown. But the mystery was solved- and I discovered that this site also radiated on two frequencies; the pulse patterns were similar to, but not the same as, the Highgate Howe site. Because of the short antenna, it must have been inductively loaded to match the transmitter. Here's a diagram of how I remember the antenna and hut to look.
Site data:
OS Grid Ref: NZ934086
Antenna type: Guyed tubular pole, 30ft height.
Transmission frequencies: 1807 and 2165kc/s
Current State:
This site was more difficult to monitor but it had totally gone by May 1995. There is a low fence remaining around the plot.
The range capability of these sites surprised me; I've no idea what power is radiated, but I could hear the Highgate Howe site's transmission on 1809kc/s at home in Sheffield.
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last update 24/4/05