reception problem

On 2009-08-19, Brian Gaff wrote:
Its amazing how much rubbish that old low loss stuff picks up. Of course I'm
not sure whether the aerial is of the correct group for digital in that
area, but I'd suggest talking to a good local firm and see what they suggest
as to where you need to go. Aerials of that age at the very least will
need attention I feel.

Crystal Palace - group A
Bluebell Hill - Group E
Dover - Group CD

All horizontal polarity. Yeah I agree, aerials of that age need
attention. The question atm is whether freesat is more worthwhile.

--
comp.john

In message , comp.john
wrote

Bluebell Hill - Group E

Until 2012 Bluebell Hill (digital) is Ch24 to Ch59, therefore wideband

--
Alan
news2009 {at} admac {dot} myzen {dot} co {dot} uk

In message , comp.john
wrote

Can you please decode what CP means?

Crystal Palace (transmitter)




--
Alan
news2009 {at} admac {dot} myzen {dot} co {dot} uk

In message , comp.john
wrote

I'm thinking of going down the freesat route because theoretically I can
take the dish with me, and it would be on a wall presumably rather than
the roof, and signal problems will go away. I wonder how it would cope
with interference though? or rain?


My cheap sky mini dish and LNB (£20 from Ebay), for Freesat, has only
failed once during rain. At that time the rain filled up a large water
butt in a couple of minutes and road outside was a river with water 6
inches deep.

If you fit a dish yourself then you may consider the value of the dish
not worth the bothering about when moving. If you have it fitted you
will have to get someone to remove it - the labour cost exceeds the cost
of the dish/LNB.

--
Alan
news2009 {at} admac {dot} myzen {dot} co {dot} uk

On Wed, 19 Aug 2009 10:36:03 +0000 (UTC), "comp.john"
wrote:

In terms of fiend strangth, is a larger number better? For example, I
looked up on the web.

Crystal Palace 61 dBuV/m
Bluebell Hill 52 dBuV/m

Have they dropped off the minus? Otherwise the converse is true. Which
is the best signal here?

No, they haven't omitted a minus. If you're comparing with my
figures, these are in different units. These are field strength in
dBuV/m, mine were power in dBm. However, note that the *relative*
ranking of the transmitters is the *same* in both sets of figures,
which is what is important.

CP is the best signal in both cases, but I suspect Sudbury should be
better still. What are the corresponding figures for Sudbury from
this source?

Where did you get these figures from? I presume they are also
predictions, rather than actual measurements? Whereas you are
interested in the reality of the situation at your home, which can
only be determined by measurement.

If you can get to the aerial yourself why not replace it if it's 19 years
old? What kind is it?

I can't get on the roof, it's a rented flat, I am on the 1st floor, and
I don't have ladders. It would need a professional in to do it, to get
access to the roof, as there is a floor above me, so it will need long
ladders.

Should not your landlord be providing a *workable* communal
arrangement for all his tenants?

I'm thinking of going down the freesat route because theoretically I can
take the dish with me, and it would be on a wall presumably rather than
the roof, and signal problems will go away. I wonder how it would cope
with interference though? or rain?

Freesat is certainly an option, but I suspect you will still need
permission of the landlord as it involves fixing something to the
outside of the house.

If you are considering satellite DIY, I have some pages on Satellite
TV, including DIY instructions and a settings calculator, he
http://www.macfh.co.uk/JavaJive/Audi...telliteTV.html

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comp.john wrote:
On 2009-08-19, Brian Gaff wrote:
Its amazing how much rubbish that old low loss stuff picks up. Of
course I'm not sure whether the aerial is of the correct group for
digital in that area, but I'd suggest talking to a good local firm
and see what they suggest as to where you need to go. Aerials of
that age at the very least will need attention I feel.

Crystal Palace - group A
Bluebell Hill - Group E
Dover - Group CD

All horizontal polarity. Yeah I agree, aerials of that age need
attention. The question atm is whether freesat is more worthwhile.

If you go the Freesat route, it would probably be worth having a dual/quad
LNB fitted and get a PVR which will allow you to watch one channel while
recording another, or record two channels while watching a recording.
--
^..^ This is Kitty. Copy and paste Kitty into your signature to help
her wipe out Bunny's world domination.

"comp.john" wrote in message
...
On 2009-08-18, Bill Wright wrote:
snip
I'm thinking of going down the freesat route because theoretically I can
take the dish with me, and it would be on a wall presumably rather than
the roof, and signal problems will go away. I wonder how it would cope
with interference though? or rain?
comp.john


Go for a Zone 2 60cm dish, only a couple of quid more than a Zone 1
the extra gain helps make up for rain attenuation
But they are harder to align

They are so cheap it's not worth removing

Steve Terry

"Java Jive" wrote in message
...
On Wed, 19 Aug 2009 10:36:03 +0000 (UTC), "comp.john"
wrote:

In terms of fiend strangth, is a larger number better? For example, I
looked up on the web.

Crystal Palace 61 dBuV/m
Bluebell Hill 52 dBuV/m

Have they dropped off the minus? Otherwise the converse is true. Which
is the best signal here?

No, they haven't omitted a minus. If you're comparing with my
figures, these are in different units. These are field strength in
dBuV/m, mine were power in dBm.

Pointless giving dBm figures when we are talking about reception, aerials,
and so forth. It's a broadcasters' thing that merely causes confusion at the
reception end of the job. Best to talk in tems of the signal level that will
appear across the terminals of a typical aerial -- say a 10 element yagi.

However, note that the *relative*
ranking of the transmitters is the *same* in both sets of figures,
which is what is important.

CP is the best signal in both cases, but I suspect Sudbury should be
better still. What are the corresponding figures for Sudbury from
this source?

Where did you get these figures from? I presume they are also
predictions, rather than actual measurements? Whereas you are
interested in the reality of the situation at your home, which can
only be determined by measurement.
Yes. I think the various methods of predicting field strength (and hence mV
on the aerial) are all pretty useless, except in the broadest of broad brush
senses. We've all had the strife caused by customers getting on the net and
confronting us with the 'fact' that all six muxes are good and strong where
they live, when in fact they are nothing of the sort. I've recently had a
residents' assn demand that the managers get a different aerial contractor
on the strength of incorrect predictions given as fact. All it needs is one
tree or one building in the way and the predictions are totally wrong.And
then there are the errors caused by the fact that the erps and radiation
patterns from the transmitters are often nowhere near what they are supposed
to be.

Bill

In article , Bill Wright
wrote:

Where did you get these figures from? I presume they are also
predictions, rather than actual measurements? Whereas you are
interested in the reality of the situation at your home, which can only
be determined by measurement.
Yes. I think the various methods of predicting field strength (and hence
mV on the aerial) are all pretty useless, except in the broadest of
broad brush senses.

Agreed. Unless you are posession of an extremely accuarate terrain data
bank, then predictions can fail dismally. all sorts of things can get in
the way that a predicted signal cannot know about. A single large tree, a
whole wood or forest, a tall building or even a not very tall one with a
metallic roof; none of these can be predicted. Nor can tidal fading or, and
terrible for analogue, multipath. It's only on site measuremenst that can
determine the strength and quality of signals.

--
From KT24

Using a RISC OS computer running v5.11

comp.john wrote:
Hello group,

I'm located in the SS0 area and reception of terrestrial freeview is
fair to poor. I live in a flat on a busy main road, and sometimes it
seems that certain vehicles (2-stroke motorbikes, tricked cars,
sometimes lorries) cause interference to the extent that it will cause
the picture to block, and then the box resets. I have a rooftop aerial
that looks like it is pointed to Dover, but some of the neighbouring
aerials seem pointed towards Crystal Palace. I'm roughly equidistant
between the two.

What I want to know is:

1. are there some freeview boxes better than others in handling marginal
signal situations and noise? Which are the best? I'm not looking for
mega features, just need to know if there is anything out there that can
make more of a limited signal. Like the difference between a Tandy
shortwave receiver and a Yaesu FRG-8800. My current noname freeview box
is pants


There where boxes with technology called Setpal, basically they were
dual conversion receivers that used an HF IF to enable better filters to
be made using cheap and non-adjustable components. Overall it was more
expensive but did offer significant improvements in sensitivity and
adjacent channel rejection. However significant is in the eye or
'meter' of the beholder and a better receiver will only help if you are
really marginal in which case the aerial guys here will say the aerial
system is defective. It did offer retailers a way to significantly
reduce returns, but at the end of the day the purchasing people don't
factor that into the buy price, and when they compared with cheap tat
from China they bought the cheap tat.

All the boxes on the market now are simple Super Het receivers and have
pretty much the same performance, of course you will get more
variability from the cheap tat as they use cheaper tuner suppliers, and
some even tweak up the gain at the expense of adjacent ch rej.


2. what can I do to eliminate electrical interference from vehicles? Not
every vehicle causes this, just a minority. Maybe they have failing or
broken interference suppressors in their ignition system. I dunno. When
they rev up, it gets worse.

thanks!