CH5 from Crystal Palace?

According to the specs on the following website, the Crystal Palace transmitter should be giving out all 6 Muxes at maximum strength (10KW). However I can't get CH5 on band 32 that is supposed to be incorporated in Mux A. I can however receive Mux1&2 without any problems. Does anyone know whether CH5 is being broadcast on band 32 within Mux A from Crystal Palace?

http://www.dtg.org.uk/retailer/tx_details/tx_s-east.htm

Hi Monkfish

Yes, Ch. 5 is within Mux 'A'.

If you can't pick it up (check the on-screen signal strength indicator for Ch. 32 (Menu - 7 - 1)) you'll need to improve your aerial arrangements a bit.

Usually the higher UHF channels suffer first from reception problems - can you get Mux C' on Ch. 34?

HTH

Thanks for replying Roxof. It seems strange that I'm getting a very good signal for Ch25 & Ch22 in Mux  1 & 2, but absolutely no signal for Ch32 in Mux A or Ch34 in Mux C. Here are my signal measurements:

MUX1 Ch25 50% strength (green) good quality
MUX2 Ch22 50% strength (green) good quality
MUXA Ch32 1% (red) poor quality
MUXB Ch28 43% (green) good quality
MUXC Ch34 1% (red) poor quality
MUXD Ch29 37% (green) good quality

There is some roll-off as the channels go up, but would a bad aerial drop off to zero at Ch32 that quickly? Any insight would be greatly appreciated

(Edited by Monkfish at 7:36 pm on July 31, 2001)

Hi Monkfish

There are various possible causes for the problem, which looks like a sharp roll-off of the highest UHF frequencies.

Firstly, aerials tend to be increasingly directional with higher frequencies - a small misalignment (from wind, perching birds etc) might be showing its effects there.

Secondly, if the cable and connectors are of any great age they might be causing problems, again more likely to affect the higher frequencies most - e.g. corrosion, damage, moisture getting in etc.

Also, if the aerial is close to other metalwork (other aerials, water tanks, wiring, gutters etc) it won't perform at its best. If it's in the loft (or lower), note that many building materials are highly absorptive too.

Add a couple of the above factors and - problems, big time!

From the signal strength readings you have i'm very nearly certain that an overhaul of your aerial and cable (not neglecting all plugs and the fly-lead) would give you perfect reception of all six multiplexes.

HTH

Well it is a new aerial in a new house with new wiring, but the aerial is in the loft Analogue Channel5 on Ch37 doesn't give a very good picture, but using a booster and portable-aerial I did manage to find a position that made it almost perfect. Unfortunately Ch32 was still not detected in this position. However this is no guarantee that it was picking up Ch32 as well. I guess I'll have to look at the aerial and wiring more closely.

Thanks Roxof, at least now I know that I should be getting Channel5 and have something to investigate