High Pressure Intereference?
 

Wotcha,

Is anyone else currently experiencing what appears to be interference due to
high atmospheric pressure?

I live about 30 miles due south of Sutton Coldfield/Lichfield and have a
high gain array giving me perfect analogue and digital strengths of average
9/10.
Last night the digital MUX's were all lower (with the ITV1 MUX dropping
below 5 at times) BBC2 analogue was snowy and Five analogue had another
floating picture behind it.

As my aerial points north I presume I've got Emley Moor coming in at the
moment, and the snowy analogue BBC2 was due to one of the Emley MUX's being
on CH40, and Five on 37 is fighting with Litchfield?

Or am I losing the plot, and just need to check my installation?


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.806 / Virus Database: 548 - Release Date: 05/12/2004

On Thu, 9 Dec 2004 12:11:40 -0000, "Doctor D" wrote:

Is anyone else currently experiencing what appears to be interference due to
high atmospheric pressure?

Analogue and digital reception in my part of South Manchester have been poor
of late. Last night was particularly bad. I'm about 30 miles from Winter
Hill.

--
When people are free to do as they please, they usually imitate each other.

Mail john rather than nospam...

Doctor D wrote:
Wotcha,

Is anyone else currently experiencing what appears to be interference due to
high atmospheric pressure?

Oh yes. This morning at 07:02 GMT I could see TF1's (France) in vision
clock displaying 08:02 floating in the background on BBC 1 Hannington.

"Mark Carver" wrote in message
...
Doctor D wrote:
Wotcha,

Is anyone else currently experiencing what appears to be interference
due to
high atmospheric pressure?

Oh yes. This morning at 07:02 GMT I could see TF1's (France) in vision
clock displaying 08:02 floating in the background on BBC 1 Hannington.



Thanks Mark.
RBR from Rowridge again I assume?

It seems too cold for this to be happening. I'm more used to it mid-summer!




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.806 / Virus Database: 548 - Release Date: 05/12/2004

On Thu, 9 Dec 2004 16:09:56 -0000, "Doctor D" wrote:


"Mark Carver" wrote in message
...
Doctor D wrote:
Wotcha,

Is anyone else currently experiencing what appears to be interference
due to
high atmospheric pressure?

Oh yes. This morning at 07:02 GMT I could see TF1's (France) in vision
clock displaying 08:02 floating in the background on BBC 1 Hannington.



Thanks Mark.
RBR from Rowridge again I assume?

It seems too cold for this to be happening. I'm more used to it mid-summer!



It happens when there is a temperature inversion. At the moment there is
ahttp://www.weatheronline.co.uk/ukukradf.htm strong inversion at about 2500 ft
due to an anticyclone over the near continent.

This inversion acts like a mirror, allowing tv signals from far off to be
reflected back and forth between the inversion and the ground and enabling them
to be "see" around the curvature of the earth. The phenomenon is not dissimilar
to that in a waveguide or fibre optic and is a form of total internal
reflection.

MJPG



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.806 / Virus Database: 548 - Release Date: 05/12/2004

Doctor D wrote:

Wotcha,

Is anyone else currently experiencing what appears to be interference due to
high atmospheric pressure?


That's not interference thats my hobby. In the old days it was called DX
TV.

For those interested in Digital DX TV the Lille transmitters should be
testing soon with what the french call TNT (Television Numerique
Terrestrial). Tele Satellite (French mag) gave main transmitter location
and MUX info for 2005. It was interesting to see that the Maximum number
of channels was to be 6 per MUX. I did not see if there were to be any
VHF MUXes.

--
Otis to Manfi Your Puckett needs WAY MORE diaphragm!

That's not interference thats my hobby. In the old days it was called DX
TV.

It's far more entertaining than most of the programming, however it was
definitely interfering with me getting on with some work last night when my
wife kept complaining about the ITV1 MUX dropping out during the Bill! :-)


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.806 / Virus Database: 548 - Release Date: 05/12/2004

Doctor D wrote:
"Mark Carver" wrote in message


Oh yes. This morning at 07:02 GMT I could see TF1's (France) in vision
clock displaying 08:02 floating in the background on BBC 1 Hannington.

Thanks Mark.
RBR from Rowridge again I assume?

Yep, I'm sure the TF1 signal was being picked up by Hannington's RBR
receiver and rebroadcast, and not received directly by me. At one point
Hannington switched to a nice clean standby feed from CP, as evidenced
by a change to London Ceefax


It seems too cold for this to be happening. I'm more used to it mid-summer!

Summer or winter, if there's high pressure along can come a lift :-)

Bill wrote:

It was interesting that there was nothing on ch38 except one very very weak
signal from the south-east that wouldn't lock. On the analyser 38 looked like a
chasm surrounded by high ground. I know we don't use 38 in the UK. Maybe they
don't use it in Europe either.

AIUI the French use it, and ironically it's one of the suggested
allocations for a DTT service on the Channel Islands, currently unable
to launch because of wrangles with.....guess who ?

In the UK it's not used for TV, to allow a 'quiet spot' for radio
astronomy. That's one reason C5 analogue (E39)from Sandy Heath is
restricted with its radiation, because of (Cambridge Uni's ?) radio
telescope.

Doctor D said the following on 09/12/2004 12:11:
Is anyone else currently experiencing what appears to be interference due to
high atmospheric pressure?

Last night the digital MUX's were all lower (with the ITV1 MUX dropping
below 5 at times) BBC2 analogue was snowy and Five analogue had another
floating picture behind it.


Can this manifest itself in the same way as ghosting?

On ITV-1 from Waltham I am currently getting deap ghosting (about 40cm
across the screen on my 21" set) during programming, but during adverts
the pattern totally changes and looks like a random image walking all
over it.

The digital multiplexs are fine, and five from Nottingham is pretty
clear for a change.

(The communal aerial install (location about 2 miles from Nottingham
city center on the "as the bird flys" line) is absolutly crap, channel 4
has diagonal lines all over it, BBC ONE and BBC TWO have a dark bar
offset about 10cm from the left which is 5cm wide and Five comes from
Nottingham extreamly snowy (the Waltham version is far too ghosty,
repeats itself about 25 times and has three of the echos very well
defined and NICAM keeps dropping out), all channels from Waltham have a
ghost image 1cm to the left of the picture too- Digital is only Mux 1,C
and D - I think the cover missing off the red thing just before the spur
to our aerial point, between the aerial and the cable going to the rest
of the a11 flats doesn't help at all))

Kev Swindells