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Old February 12th 10, 09:57 AM posted to uk.tech.digital-tv
charles
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Posts: 4,016
Default No waterproofing on the f conn and no cable clips?

In article , wrote:
On 12 Feb, "Doctor D" wrote:


Whilst I would agree that they don't have the gain of a Yagi, they are
useful around here even in weak signal areas as channel allocation runs
from C21 to C63. I have ended up with a better balance of levels by
using a LP and low noise amplifier, rather than a wideband Yagi with
very low gain at C21.

I've recently replaced my loft aerial, a supposedly high gain contract
yagi with an external log (and new feeder), as after DSO a group A is not
enough. There is more signal from the log, allowing me to dispense with
the distribution amp and substitute a 4 way splitter, retaining a
decoding margin of over 18dB with the current low power MUXs.


Field strength is good, I'm about 12 miles LOS from a 500kw main station.
Slight ghosting was a problem with the analogue. I haven't looked too
closely since I changed the aerial but it's no worse.


Remember that roofing material can attenuate signals to a very significant
extent. In upper band V it can easily be a 20dB loss. Red concrete roof
tile, widely used in the 60s, 70s and 80s, go their colour from iron oxide
(aka rust). many modern roof tiles have metal reinforcing layer inside.
And if teh roff inslation has metal foil involved .......

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