A Home cinema forum. HomeCinemaBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HomeCinemaBanter forum » Home cinema newsgroups » UK digital tv
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Reception problems during heavy rain?



 
 
Thread Tools Display Modes
  #1  
Old September 21st 18, 05:12 AM posted to uk.tech.digital-tv
Bill Wright[_3_]
external usenet poster
 
Posts: 3,083
Default Reception problems during heavy rain?

My aerial has a clear sight of Emley Moor and my distribution system
normally delivers a perfect signal to all the TV sets and recorders.
However, during the freakishly heavy rain in the early hours of today
our reception suffered a long series of brief break-ups. This
observation is based on my recording of Horizon HD on BBC4 (com 7).
I've never seen evidence of heavy rain affecting terrestrial UHF
reception, though of course that doesn't mean it can't happen. I'm
musing about the mechanism.
1. Something wrong at the transmitter; weather-related or otherwise
2. The link between playout and the transmitter; weather-related or
otherwise
3. My aerial being effectively submerged; the raindrops merging enough
to behave almost like continuous water
4. Path loss caused by the raindrops merging enough to behave almost
like continuous water.

If anyone else recorded Horizon I'd be interested to know if they had
reception problems. COM7 is on much lower power from Emley than the
'main' muxes', but even so we normally receive a signal with an
unmeasurably good s/n ratio.

Horizon was about black holes and quantum mechanics. My understanding
was superficial at best.

Bill
  #2  
Old September 21st 18, 09:18 AM posted to uk.tech.digital-tv
Woody[_4_]
external usenet poster
 
Posts: 1,971
Default Reception problems during heavy rain?

On Fri 21/09/2018 04:12, Bill Wright wrote:
My aerial has a clear sight of Emley Moor and my distribution system
normally delivers a perfect signal to all the TV sets and recorders.
However, during the freakishly heavy rain in the early hours of today
our reception suffered a long series of brief break-ups. This
observation is based on my recording of Horizon HD on BBC4 (com 7).
I've never seen evidence of heavy rain affecting terrestrial UHF
reception, though of course that doesn't mean it can't happen. I'm
musing about the mechanism.
1. Something wrong at the transmitter; weather-related or otherwise
2. The link between playout and the transmitter; weather-related or
otherwise
3. My aerial being effectively submerged; the raindrops merging enough
to behave almost like continuous water
4. Path loss caused by the raindrops merging enough to behave almost
like continuous water.

If anyone else recorded Horizon I'd be interested to know if they had
reception problems. COM7 is on much lower power from Emley than the
'main' muxes', but even so we normally receive a signal with an
unmeasurably good s/n ratio.

Horizon was about black holes and quantum mechanics. My understanding
was superficial at best.


For a start, don't believe that any transmitter that in theory is omni
is actually that. Despite you being LoS it does not follow that you are
not in one of the many small reductions ('nulls') of the coverage pattern.
Are you still using a group B or have you upgraded to a log periodic
yet? I'm about 26 miles away and the change from a (supposedly) wideband
multibeam to a LP has made a world of change in signal stability on
32/34 and 56.

It is possibly that the standby aerial was put into use for some reason
- indeed it may have been put into service longer term for the 700MHz
clearance and your signal has not been affected. However put into the
path such horrendously heavy rain as was around last night and it could
have serious effects. In my limited experience of rain effects IMO it is
likely to affect the quality rather than the signal strength, and as we
all know with DTV it is the quality that matters.


--
Woody

harrogate three at ntlworld dot com
  #3  
Old September 21st 18, 10:01 AM posted to uk.tech.digital-tv
Ian Jackson[_7_]
external usenet poster
 
Posts: 187
Default Reception problems during heavy rain?

In message , Woody
writes
On Fri 21/09/2018 04:12, Bill Wright wrote:
My aerial has a clear sight of Emley Moor and my distribution system
normally delivers a perfect signal to all the TV sets and recorders.
However, during the freakishly heavy rain in the early hours of today
our reception suffered a long series of brief break-ups. This
observation is based on my recording of Horizon HD on BBC4 (com 7).
I've never seen evidence of heavy rain affecting terrestrial UHF
reception, though of course that doesn't mean it can't happen. I'm
musing about the mechanism.
1. Something wrong at the transmitter; weather-related or otherwise
2. The link between playout and the transmitter; weather-related or
otherwise
3. My aerial being effectively submerged; the raindrops merging
enough to behave almost like continuous water
4. Path loss caused by the raindrops merging enough to behave almost
like continuous water.
If anyone else recorded Horizon I'd be interested to know if they
had reception problems. COM7 is on much lower power from Emley than
the 'main' muxes', but even so we normally receive a signal with an
unmeasurably good s/n ratio.
Horizon was about black holes and quantum mechanics. My
understanding was superficial at best.


For a start, don't believe that any transmitter that in theory is omni
is actually that. Despite you being LoS it does not follow that you are
not in one of the many small reductions ('nulls') of the coverage
pattern.
Are you still using a group B or have you upgraded to a log periodic
yet? I'm about 26 miles away and the change from a (supposedly)
wideband multibeam to a LP has made a world of change in signal
stability on 32/34 and 56.

It is possibly that the standby aerial was put into use for some reason
- indeed it may have been put into service longer term for the 700MHz
clearance and your signal has not been affected. However put into the
path such horrendously heavy rain as was around last night and it could
have serious effects. In my limited experience of rain effects IMO it
is likely to affect the quality rather than the signal strength, and as
we all know with DTV it is the quality that matters.

Maybe the situation is not quite the same, but Chatton (north
Northumberland) is (or, at least, was when it came into service) a
high-power off-air relay off Pontop Pike (about 50 miles to the south).
It's about 8 miles inland from Seahouses, full LOS.

In Seahouses, while watching (analogue) TV one warm evening, a bank of
dense fog rolled in off the sea. It became increasingly apparent that
there was a growing amount of multipath ghosting on the picture. It
steadily got worse and worse, until the picture was barely viewable -
then after a momentary break, it suddenly became OK again.

The explanation given to me was that there were two receiving aerials -
one half way up the mast, and one near the top. It was the top one that
was normally in use - and the lower one was a standby (and they had
switched to it).

What had happened was that the fog had caused a sudden change in the
temperature of the air and on its density, and this had led to an
unstable ducting effect, which in turn had severely affected the
'high-up' path of propagation. Lower down had been less disturbed.

So if fog can cause this sort of effect, can rain do the same -
especially if it is sudden and torrential?
--
Ian
  #4  
Old September 21st 18, 12:18 PM posted to uk.tech.digital-tv
JNugent[_6_]
external usenet poster
 
Posts: 22
Default Reception problems during heavy rain?

On 21/09/2018 04:12, Bill Wright wrote:
My aerial has a clear sight of Emley Moor and my distribution system
normally delivers a perfect signal to all the TV sets and recorders.
However, during the freakishly heavy rain in the early hours of today
our reception suffered a long series of brief break-ups. This
observation is based on my recording of Horizon HD on BBC4 (com 7).
I've never seen evidence of heavy rain affecting terrestrial UHF
reception, though of course that doesn't mean it can't happen. I'm
musing about the mechanism.
1. Something wrong at the transmitter; weather-related or otherwise
2. The link between playout and the transmitter; weather-related or
otherwise
3. My aerial being effectively submerged; the raindrops merging enough
to behave almost like continuous water
4. Path loss caused by the raindrops merging enough to behave almost
like continuous water.

If anyone else recorded Horizon I'd be interested to know if they had
reception problems. COM7 is on much lower power from Emley than the
'main' muxes', but even so we normally receive a signal with an
unmeasurably good s/n ratio.

Horizon was about black holes and quantum mechanics. My understanding
was superficial at best.


Does the signal get to the transmitter site via a microwave link?
  #5  
Old September 21st 18, 02:27 PM posted to uk.tech.digital-tv
Terry Casey[_2_]
external usenet poster
 
Posts: 858
Default Reception problems during heavy rain?

In article , harrogate3
@ntlworld.com says...

Are you still using a group B or have you upgraded to a log
periodic yet? I'm about 26 miles away and the change from a
(supposedly) wideband multibeam to a LP has made a world of
change in signal stability on 32/34 and 56.


You must be a very brave man to doubt the aerial installation
quality of such an accomplished expert in the field as Bill!

--

Terry

---
This email has been checked for viruses by AVG.
https://www.avg.com

  #6  
Old September 21st 18, 02:47 PM posted to uk.tech.digital-tv
NY
external usenet poster
 
Posts: 1,579
Default Reception problems during heavy rain?

"Terry Casey" wrote in message
...
In article , harrogate3
@ntlworld.com says...

Are you still using a group B or have you upgraded to a log
periodic yet? I'm about 26 miles away and the change from a
(supposedly) wideband multibeam to a LP has made a world of
change in signal stability on 32/34 and 56.


You must be a very brave man to doubt the aerial installation
quality of such an accomplished expert in the field as Bill!


Yes, if there is anyone in the world that you'd expect to have a good aerial
delivering the best possible signal, it would be the esteemed Bill.

  #7  
Old September 21st 18, 03:16 PM posted to uk.tech.digital-tv
R. Mark Clayton[_2_]
external usenet poster
 
Posts: 756
Default Reception problems during heavy rain?

On Friday, 21 September 2018 04:12:55 UTC+1, wrote:
My aerial has a clear sight of Emley Moor and my distribution system
normally delivers a perfect signal to all the TV sets and recorders.
However, during the freakishly heavy rain in the early hours of today
our reception suffered a long series of brief break-ups. This
observation is based on my recording of Horizon HD on BBC4 (com 7).
I've never seen evidence of heavy rain affecting terrestrial UHF
reception, though of course that doesn't mean it can't happen. I'm
musing about the mechanism.
1. Something wrong at the transmitter; weather-related or otherwise
2. The link between playout and the transmitter; weather-related or
otherwise
3. My aerial being effectively submerged; the raindrops merging enough
to behave almost like continuous water
4. Path loss caused by the raindrops merging enough to behave almost
like continuous water.

If anyone else recorded Horizon I'd be interested to know if they had
reception problems. COM7 is on much lower power from Emley than the
'main' muxes', but even so we normally receive a signal with an
unmeasurably good s/n ratio.

Horizon was about black holes and quantum mechanics. My understanding
was superficial at best.

Bill


Water in the aerial cable?

Satellite reception drops off in heavy rain, UHF very slightly.
  #8  
Old September 21st 18, 03:42 PM posted to uk.tech.digital-tv
Bill Wright[_3_]
external usenet poster
 
Posts: 3,083
Default Reception problems during heavy rain?

On 21/09/2018 08:18, Woody wrote:
On Fri 21/09/2018 04:12, Bill Wright wrote:
My aerial has a clear sight of Emley Moor and my distribution system
normally delivers a perfect signal to all the TV sets and recorders.
However, during the freakishly heavy rain in the early hours of today
our reception suffered a long series of brief break-ups. This
observation is based on my recording of Horizon HD on BBC4 (com 7).
I've never seen evidence of heavy rain affecting terrestrial UHF
reception, though of course that doesn't mean it can't happen. I'm
musing about the mechanism.
1. Something wrong at the transmitter; weather-related or otherwise
2. The link between playout and the transmitter; weather-related or
otherwise
3. My aerial being effectively submerged; the raindrops merging enough
to behave almost like continuous water
4. Path loss caused by the raindrops merging enough to behave almost
like continuous water.

If anyone else recorded Horizon I'd be interested to know if they had
reception problems. COM7 is on much lower power from Emley than the
'main' muxes', but even so we normally receive a signal with an
unmeasurably good s/n ratio.

Horizon was about black holes and quantum mechanics. My understanding
was superficial at best.


For a start, don't believe that any transmitter that in theory is omni
is actually that. Despite you being LoS it does not follow that you are
not in one of the many small reductions ('nulls') of the coverage pattern.


No, but the signals levels are stable and very strong, and as far as I
know neither Emley Moor or my house were temporarily relocated last night.

But yes, 'omni' is a myth. In my rigging days it was quite noticeable
how signal levels varied between places the same distance from the tx
but on different bearings. Beam tilt is also a factor.

Are you still using a group B


Yes. I expected I'd have to change it but the out-of-band muxes seem to
be perfectly OK. We don't receive the Leeds mux. All muxes are levelled
by filters after a low gain preamp and before combining with other signals.

Bill
  #9  
Old September 21st 18, 03:44 PM posted to uk.tech.digital-tv
Bill Wright[_3_]
external usenet poster
 
Posts: 3,083
Default Reception problems during heavy rain?

On 21/09/2018 09:01, Ian Jackson wrote:

In Seahouses, while watching (analogue) TV one warm evening, a bank of
dense fog rolled in off the sea. It became increasingly apparent that
there was a growing amount of multipath ghosting on the picture. It
steadily got worse and worse, until the picture was barely viewable -
then after a momentary break, it suddenly became OK again.

The explanation given to me was that there were two receiving aerials -
one half way up the mast, and one near the top. It was the top one that
was normally in use - and the lower one was a standby (and they had
switched to it).

What had happened was that the fog had caused a sudden change in the
temperature of the air and on its density, and this had led to an
unstable ducting effect, which in turn had severely affected the
'high-up' path of propagation. Lower down had been less disturbed.


Interesting.

Bill
  #10  
Old September 21st 18, 03:48 PM posted to uk.tech.digital-tv
Bill Wright[_3_]
external usenet poster
 
Posts: 3,083
Default Reception problems during heavy rain?

On 21/09/2018 13:27, Terry Casey wrote:
In article , harrogate3
@ntlworld.com says...

Are you still using a group B or have you upgraded to a log
periodic yet? I'm about 26 miles away and the change from a
(supposedly) wideband multibeam to a LP has made a world of
change in signal stability on 32/34 and 56.


You must be a very brave man to doubt the aerial installation
quality of such an accomplished expert in the field as Bill!


Yes but I am very lazy. However I did a lot of work on my roof last
August. I checked the aerials for safety but didn't bother to change the
Group B for a log.

Bill
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Signal from converter box stops when there's a heavy rain John Ritchie High definition TV 3 November 7th 08 02:49 AM
Channel dropout - BBC channels and especially in heavy rain UK digital tv 10 February 10th 06 09:17 AM
Channel dropout - BBC channels and especially in heavy rain UK digital tv 0 February 9th 06 11:28 PM
Reception in rain Dave W. UK sky 3 November 21st 04 08:32 AM


All times are GMT +1. The time now is 01:56 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2004-2018 HomeCinemaBanter.
The comments are property of their posters.