Chris Jones G8GFB
The spirit of the WS10 lived on...
Many Group members will be well acquainted with the WS10 and the story behind it. A picture of WS10 vehicles deployed "somewhere" displayed on the Group Home Page (see above) reminded me on my time doing broadcast communications for the BBC, a large part of which was temporary SHF links for television outside broadcasts; the similarities between the two systems could not be ignored, so I found some old photographs that I had taken thinking that they might be of passing interest to Group members. Hindsight being a precise science I wish I had taken more, showing the evolution of the equipment and vehicles, but...
I apologise for the rather indifferent quality, but as I said, they are quite old!
The above picture was taken at Winter Hill (north of Bolton) during a "Grand National" race meeting at Aintree (Liverpool). The 2 systems on the vehicle roof pointing " left", and the one on the building roof (near the ladder, partially obscured by the roof) are pointing towards Liverpool, while the other 4 (pointing half-right) are pointing towards central Manchester. The permanent link site in Manchester was the roof of "Piccadilly Plaza", some 30 floors up...
The "large" dishes are all 4' diameter, the single small one is 2' in diameter. The large lump in front of the vehicle is a 6kVA generator, based on an air-cooled flat twin Enfield diesel engine; mercifully it was only there in case the AC supply to the whole site failed, and we didn't have to listen to it all day!
Another photograph of the same installation. This clearly shows the " dual-head" configuration (other than the single headed link on the small dish) that was used. The large cables from the heads carried power and video (with a superimposed audio subcarrier) to the control units in the vehicle. Although it was possible to connect receiver and transmitter heads directly at IF, this was not much favoured as it made cross-patching in the event of problems hard to achieve (paricularly in a snow storm). All the heads with this generation of equipment were fixed frequency, with channel filtering in the input (or output) waveguides. The "metalwork" between the heads and the aerials included circulators. The position of the single headed link on its mounting would point to its being a receiver, although blanking plates were available for unused circulator ports to ensure the necessary "bounce". From the appearance of the aerial, the " small" link on the left was operating on 12GHz; all the others are on 7GHz. The "white pole" on the right hand side of the picture is the low band FM engineering R/T.
|This shows the aerials for a simple "mid-point", although its installation on a Fire Station tower in Carlisle (for the 1983 General Election campaign) made it a little more complicated. The lower aerial was the incoming link from a venue less than a couple of hundred yards away; from the aerial feed it appears to be a 2.5GHz link. The upper aerial was for a short outgoing link to "Hilltop Heights" to the south of Carlisle city centre (near Harraby BT radio station) where the link was able to connect to a permanent network. Both links here use 2' dishes.|
|A fire engine comes to investigate the intruder in the yard! Note again the diesel generator in front of the radio link vehicle; the generators would usually be towed by the vehicle that needed the power, with a second (spare) towed by a Land Rover. Here the generator is only to cover the possible loss of the normal supply.|
The need for height could sometimes not be met by using buildings, but at least Communications personnel were spared the need to fill sandbags to stabilise a 60' tower! However, the "60'" figure remained in business, as the next option was an "Eagle Tower".
|An Eagle Tower rigged with a 4' dish on the top, and a 2' dish rigged on the platform handrail. To achieve this, the tower has been extended slightly from its "rest" position at 30'. The erection of the tower from its travelling position, and its extension up to 60' was hydraulic, driven from a PTO on the road engine. During their lifetimes the towers were "re-chassised", and cabs changed when wear and tear necessitated. One even had a cab fitted that had been a "Green Goddess" spare.|
They were not the nicest vehicles to drive; when travelling, the whole tower structure lay forward across the cab, with a projection of perhaps 5 feet beyond the front grille. Made getting out of side roads without getting smacked by another vehicle quite a challenge, because with the overhang above the "white line", the driver's ability to see both ways was very limited!
With a maximum speed of perhaps 45mph (if the driver was lucky) it could take a long time to get anywhere. On the plus side there was never any need to do weight training in the gym; there was no power steering, so driving anywhere but the open road could be quite hard work!
Although the Eagle towers were equipped with 4 wheel drive, this was more a legacy of their being on built on the Bedford chassis; they required firm ground for their use. The links trucks were standard production vehicles, so it was not unknown for them to get stuck partway across a field. If this happened, the usual solution was to find a local farmer who would tow the vehicle out with his tractor for a small "consideration". On one occasion, a vehicle lost traction on a muddy slope and just flopped on to its nearside; the only casualty was a 141MHz end fed aerial, the fibreglass outer sheath of which got cracked. A car body repair kit from a local shop soon put that right. The Land Rovers, of course, all had a 4 wheel drive capability and we all became fairly adept at off-roading with 1 ton generators behind.
|An Eagle Tower fully extended to 60'; the vehicle itself
is hidden behind the link truck. The whole link at the top could
be slewed electrically to get it on bearing; there were also Magslip indicators,
but if they worked (which they didn't) they were of little use as there
was no gyrocompass fitted to determine where North was anyway! There
was no vertical adjustment possible "remotely"; if necessary
would be dropped to platform level and the link tilted using a lead
screw provided for the purpose. A small spirit level would be placed
on the aerial waveguide, and the link trimmed in "half-bubble" increments.
This photograph was taken at Wigan Rugby League Ground - the old
the new! The watercourse is the River Douglas.
|Whatever this OB was, it required 2 vehicles at this mid-point, (relay) 3 generators, and 2 Land Rovers. Date: late 60s / early 70s. Note the absence of any attempt at concealment or camouflage! This time, however, there was no option; we had to have the generators running.|
|Sometimes it was necessary to provide mid - points without a vehicle. This one was at the top of a block of flats. The 4 nearly identical units with meters are the receiver and transmitter control units (2 off each). Other equipment includes a video test signal generator, a video S/N measuring set, a Philips PM3217 oscilloscope and a Levell audio oscillator. The event must have been important because a standby battery (36v) has been included. There must have been a PF2FMH portable R/T somewhere because a charger is visible on top of the S/N measuring set. The author's spectacles and "smoking equipment" are just visible on top of the GE4M/561 video test signal generator!|
The job was not without its hazards, but they were altogether more mundane that those experienced by WS10 operators. Cowpats were a commonplace problem; sometimes the cows themselves would use the vehicles as handy scratching posts. On one occasion a bull threatened to take exception to the intrusion into the field; it belonged to him and his harem. Meal breaks were an almost unheard of luxury; takeaways the norm. The quantity of fish and chips (or special fried rice) consumed, would be more than enough to make any self-respecting nutritionist faint.
Perhaps the most common "downside" was the weather. If it was raining, we got wet. If it was snowing, we got cold and wet. It was always a bit odd hearing one's employer broadcasting "Police advice" not to travel unless the journey was essential, knowing that one had to drive 100 - 200 miles to provide a link for a sporting event that would probably be cancelled because of the weather. As in the Doppler Effect, "Shift happens".
There were, of course, other links. Race meetings frequently have a car-mounted camera running inside the rails, and now no marathon or other road race would be complete without a camera mounted on either a motorcycle or quad bike up there with the race leaders. In the "early days" these links tended to operate somewhere in Band V, but as time passed 2.5GHz systems became the norm. These mobile systems could be problematic enough in open spaces, but almost by definition road races tend to be (at least in part) in built up or semi built up areas. Even with several "receive" terminals there would be sections of a route where coverage would fail, usually because of multipath problems rather than lack of signal strength; very often the mobile aerials were omnidirectional which only compounded the problem.
It required the "common sense" part of a cameraman's brain to be incapacitated for him to ride pillion on a motorcycle with his camera - facing backwards, albeit at what (for a motorcycle at any rate) was a slow speed.
|A "roving eye" in preparation at a race meeting. The Citroen was the only vehicle with a suspension that would take the total equipment weight and remain "level". The camera operator would be strapped firmly to the seat on the roof. This car has a Band V transmitter for the vision link. Note the little (petrol) generator towed behind. This picture was taken from the 30' platform on an Eagle tower; the shadow of the tower at 60' is clearly visible.|
All the photographs date from before 1984; as time passed, the equipment improved. The noisy Enfield generators were replaced with almost silent 10kVA sets in acoustic enclosures; 3 were built into "Mk10" radio link vehicles, which were surprisingly quiet inside - less than 65dBA. The engineers could work in this all day without even noise fatigue, never mind noise induced hearing loss. The Microwave Associates Mk2 radio link equipment shown became the Mk3; more RF power, switchable frequencies, easier cabling, 24 volt DC capability (better than 36 volts!). The vehicles even had 12 x 8 video and 8 x 8 audio matrices for hot switching and so on...
The Eagle towers (all originally manufactured before 1965) were phased out and replaced by hydraulic platforms by Simon Engineering; the last tower was still working - just - in Birmingham in 1996. The hydraulic platforms were a major advance; easier to rig and deploy, and capable of supporting more equipment, and higher!
|A Simon S220 hydraulic platform, developed specifically for OB communications from the Fire Service model. The “pipework” that would normally have carried water to the monitor on the platform carried a variety of cables for radio links, (by now operating on triaxial cable) VHF/UHF systems (mainly URM67, augmented by a couple of lower loss cables) some DC power (24 volts) and audio cabling, the commonest use of which was feeding the output of an anemometer down to a remote display unit. There was also cabling for remote pan and tilt of a radio link mount (permanently installed in the cage) manufactured by Messrs Vinten of Bury St Edmunds. It would seem that on the day this photograph was taken the controller for the pan / tilt unit (not manufactured by Vinten) had failed again; there is a hole where it ought to be. Additional cables could be run through “pig – tail” loops along the 3 booms, but their weight had to be deducted from the maximum payload.|
I just regret not having more pictorial reminders of them, because now it has all changed out of recognition. Land based links have virtually disappeared, displaced by satellite systems. The platforms bought for communications use have gone, (after what was really a very short working life) and those used for cameras all hired in; watch any major golf tournament - they will be present in "breeding colony" numbers! If any more informative photographs can be found they will be offered for an amended version of this article.
The BBC's coat of arms is adorned with the motto "Nation shall speak peace unto Nation". If those of us in communications had our own motto, it was probably the responsibility - shifting "it's all right leaving me", or (when things were going seriously wrong - not an uncommon occurrence) "if you can't take a joke you shouldn't have joined".
I think our predecessors with the WS10 would have recognised that one.
Chris Jones G8GFB