"charles" <
cha...@candehope.me.uk> wrote in message
news:564caa82...@candehope.me.uk...
They couldn't put aerials lower because (1) the tower is made of
reinforced concrete and thus a pretty good signal blocker and (2)
bringing the aerials down the better part of 200ft would seriously
reduce the coverage - which has to be maintained for regulatory
purposes.
The aerials were replaced for DSO. 800MHz clearance and now the
upcoming 700MHz clearance where not even thought about at DSO.
I doubt the replacement aerials will be a wideband system due to loss
of efficiency and thus erp. They might however put two sets of
aerials, one upper, one lower, for the different bands in case someone
somewhere decides the whole of the UK should be in A-group on multiple
SFNs!
There are two sets of aerials split between the upper and lower
sections of the candle and a third low-gain set lower down for service
standby. There are also VHF/FM aerials splashed around in the lower
section for a couple of commercial stations along with DAB in one side
(directional.)
For DSO aerial work was done overnight so that reduced power and some
breaks could be tolerated. Not a problem when they were working on the
lower half, but when the upper half was being done there had to be a
transmission break to allow the riggers to climb up through the lower
half. One of the most difficult jobs ever done up there was
replacement of the aircraft warning light on the top of the candle -
but don't ask me why. You might be surprised that without lighting it
is pitch black inside the candles.
--
Woody
harrogate3 at ntlworld dot com