The windfarm at Ovenden Moor is the largest and most obvious (I can see it from my home in Yeadon). I don't know its elevation but it can't be far off LBA's elevation of 682ft, if not higher.

As far as I am aware, yes. The replacement program is scheduled to run until 2021 and involves the supply of 20 PSR and 4 SSR systems.

The PSR at Prestwick is an EN4000, as NorthSouth correctly pointed out, a hybrid Watchman but it is being replaced by a Terma Scanter 4002. This has been on site for over a year but hasn't been flight trialed yet.

I noticed on eBay yesterday a couple of radar heads for sale, a Watchman and a Raytheon. Both, apparently, unused. I think I'll pass !

Is there any market for used S-band radars or do they end up in the scrapyard ? I often wonder what happened to the old ACR430 that graced Leeds Bradford for more than twenty years. The Watchman has outlived it by some margin.

Better tell Talkdownman about those radar heads; they're always searching for spare parts for Lasham Radar.
By the way, the '430 is X-band (3cm) not S-band (10cm)
From memory, the 430 head was not dissmilar to the Watchman head, the difference being the 'guts'.
The 430 was a development of the 424/ACR7 which in turn was a development of a shipboard radar; the 424 only had a 'pencil' beam whereas the 430 had a pencil beam and a 'cosecant squared' beam same as the Watchman.
The 430 operated on a pulse generated by a klystron or magnetron whereas the Watchman used a 'Travelling Wave Tube' or 'twit'.
The 430 had no MTI, the Watchman had 'Adaptive MTI'.

There was a Decca 424 at Leeds before the 430. It ended up at Brough.

Would Raytheon and Watchman spares be any good for a 424 ? It used to be Ford Anglia belts that were sought after !

From what TDM tells me, it's valves they're short of; but then none of you lot probably knows what a thermionic valve is.

I do not but I guess it's heat-related. And a valve.

My TV set used to have about 24 of them.

Oh so have they now decided that the Scanter will do the full job, without a replacement for the EN4000? I understood there was some doubt about providing the service with a radar that only has a range of 40nm

Ha ha that's a good one! NATS sign up to a contract that doesn't cover its costs? I would have thought £1.5 billion would just about cover it. But they're already way behind the contracted schedule and not getting any quicker.

Ovenden is visible on the LBA Watchman and is not mitigated.

Interesting. Perhaps windfarms aren't an issue round here. However I don't work in ATC so I don't know for certain.

Valves were what made 'steam' radios work. They were superseded by transistors in the early '60s and they have now been pushed aside by silicon chips.
Y'know those documentaries about the Bombes used to make Enigma decoding work? Did you see those funny shaped glass things like lightbulbs inside the Bombes?
They are valves.

A fascinating discussion indeed, I wonder how much 'Radar Theory' is included in modern APS/ACS courses?

@ ZOOKER
Who can forget John Townsend's erudite explanations of tangential fade & associated equations ? ;-)

...and his Sine Wave 'soft-shoe-shuffle'...

JT got a lot of radar theory across to a lot of students who wouldn't otherwise have got it! Most memorable and entertaining! I owe JT...

I think many of us do TDM. Always enjoyed his lectures, and using a primary-only fluoride radar was one of the most satisfying aspects of the job.

Is a fluoride radar a green monochrome display, as opposed to an orange one ? They once had those at Blackpool, Stansted and Birmingham (Ferranti ?), as I recall, probably fed by any number of primary radar heads.

Our Decca 424 was orange. We have succumbed to flat screens now. I understand the old 1950s kit has gone to the Plessey museum on the IOW. The fluoride had lost almost all of its persistence towards the end. We were vectoring fast-decaying pin-heads.