In article , scribeth
thus
On 12 Jun,
The Natural Philosopher wrote:

Oddly enough that is actually what suits many people: The transmitters
are in general not far away for TV, its the multipath

Multipath performance is much better on digital than analogue.

and the other stations that get collected that cause problems on digital
in my experience

The biggest problem (other than in group A areas) is that STBs can't
differentiate between weaker out of area stations on lower channels and the
correct local signals, as they scan the bands from low to high. This will
result in poorer reception, and as was found in the Winter Hill switchover,
reception of the wrong regional programmes. A workaround for this is to
remove the aerial until the auto tune has passed the lower channels. A better
solution would be for the firmware to ask for the postcode or local
transmitter, as some of the computer TV card software does.



Indeed!, Mr Wright Yorkshires finest rigger has summatt to mutter about
that too;!....


http://www.wrightsaerials.tv/article...at-retunes.pdf
--
Tony Sayer

tony sayer wrote:
In article , The Natural Philosopher
scribeth thus
tony sayer wrote:
In article , PeterC
scribeth thus
On Fri, 11 Jun 2010 11:19:49 +0100, Terry Casey wrote:

PeterC wrote:
On Fri, 11 Jun 2010 01:38:14 +0100, Bill wrote:

In message , Alan
writes
In message , spamlet
wrote

I think somebody mentioned transmitters: Crystal Palace in particular.
Don't know how to tell which one /ones I'm using anyhow.
Put you post code into
http://www.wolfbane.com/cgi-bin/tvd.exe?

Take the above as a guide only, it has a few strange ideas. For
instance it tells me I need an extra high gain amplified aerial to
receive a station that I can see on a screwdriver stuck in the serial
socket of the TV!
Same here (although a bigger screwdriver, at 43km). Only 5 is poor but
watchable on ~30yo aerial and co-ax.
The gain of a yagi aerial drops off very sharply above the highest
frequency it was designed for.

Group A used to stop at Channel 34, with several channels between Group
A and Group B being reserved for non-broadcast use.

It was eventually decided to release Channel 37 for use by (Channel) 5
but all the Group A aerials then installed didn't cover that channel!
(Modern Group A aerials now cover a wider span and DO include Ch37.)

Therefore, your 30 year old aerial (assuming we're talking about Gp A)
and my 40 year old Gp A aerial don't perform very well on 5.
Ah, I wondered why such an old aerial was so good (apart from the co-ax has
a lot of copper in it - better than so-called 'satellite' stuff).

Its more to do with the screening than the copper. Some very expensive
cables use copper plated ally inner conductors!...

I was impressed when the riggers fitted what looks like a good log-periodic
job next door and not bacofoil, so I'll get that company to do mine.
Logs are fine for very flat gain over the band .. but gain is what
there're not that good at;!..

Side rejection is very good tho..

Oddly enough that is actually what suits many people: The transmitters
are in general not far away for TV, its the multipath and the other
stations that get collected that cause problems on digital in my experience.

Usually in Digital reception they add together which is one of the good
things about digital transmission...

Ok I have a distribution booster, but the set top boxes always report
good signal levels, but poor signal quality when I have 'issues'


I ought to replace teh analogue with a good log wotsit in the loft..

May not be necessary unless you have a very wide band of frequencies to
deal with. I bet the "loft" has a load of chicken type wire therein?...

Nah. The aerial is under the tiled pseudo extension the bloody planners
made me put in..

straight through the tiles sideways to sudbury..

are in general not far away for TV, its the multipath and the other
stations that get collected that cause problems on digital in my experience.

Usually in Digital reception they add together which is one of the good
things about digital transmission...

Ok I have a distribution booster, but the set top boxes always report
good signal levels, but poor signal quality when I have 'issues'


I ought to replace teh analogue with a good log wotsit in the loft..

May not be necessary unless you have a very wide band of frequencies to
deal with. I bet the "loft" has a load of chicken type wire therein?...

Nah. The aerial is under the tiled pseudo extension the bloody planners
made me put in..

straight through the tiles sideways to sudbury..

Where did you get all these "ghosts" you referred to earlier?..





--
Tony Sayer

On Sat, 12 Jun 2010 14:52:37 +0100, tony sayer wrote:

In article , PeterC
scribeth thus
On Fri, 11 Jun 2010 18:43:35 +0100, tony sayer wrote:

Ah, I wondered why such an old aerial was so good (apart from the co-ax has
a lot of copper in it - better than so-called 'satellite' stuff).


Its more to do with the screening than the copper. Some very expensive
cables use copper plated ally inner conductors!...

Ouch! - I remember when the local 400kV line was renewed: compacted ally
and bloody noisy it was too (audibly).

I was impressed when the riggers fitted what looks like a good log-periodic
job next door and not bacofoil, so I'll get that company to do mine.

Logs are fine for very flat gain over the band .. but gain is what
there're not that good at;!..

Side rejection is very good tho..

Necessary here, as next door's roof is a few degrees off the line and half
a house-pitch to one side.

That side rejection referred to rejection of signals coming in from the
side like distant interfering transmitters or strong reflected (ghost)
signals...

OK, so log is still an option.

I'd love to have something in the loft, but at 43km (Oxford - Sandy is the
same distance but there's a bloody gert railway embankment 100m away in
that direction) and pointing through the gable wall...
--
Peter.
2x4 - thick plank; 4x4 - two of 'em.

tony sayer wrote:
are in general not far away for TV, its the multipath and the other
stations that get collected that cause problems on digital in my experience.
Usually in Digital reception they add together which is one of the good
things about digital transmission...

Ok I have a distribution booster, but the set top boxes always report
good signal levels, but poor signal quality when I have 'issues'


I ought to replace teh analogue with a good log wotsit in the loft..
May not be necessary unless you have a very wide band of frequencies to
deal with. I bet the "loft" has a load of chicken type wire therein?...
Nah. The aerial is under the tiled pseudo extension the bloody planners
made me put in..

straight through the tiles sideways to sudbury..

Where did you get all these "ghosts" you referred to earlier?..

In laws setup. somewhere else.


If you mean multipath

I suffer from other stations presumably sur le continent.

On 12 June, 14:40, The Natural Philosopher
wrote:
wrote:
On 12 Jun, *
* * *The Natural Philosopher wrote:

Oddly enough that is actually what suits many people: The transmitters
are in general not far away for TV, its the multipath

Multipath performance is much better on digital than analogue.

Not with waving trees it aint.

Indeed.
My STB picture quality runs in sympathy with the wind gusting. At a
wind/tree null point, the picture locks and blocks up like Sinclair
Spectrum graphics. On analogue there's no noticeable change in
picture quality.

In article
s.com, scribeth thus
On 12 June, 14:40, The Natural Philosopher
wrote:
wrote:
On 12 Jun, *
* * *The Natural Philosopher wrote:

Oddly enough that is actually what suits many people: The transmitters
are in general not far away for TV, its the multipath

Multipath performance is much better on digital than analogue.

Not with waving trees it aint.

Indeed.
My STB picture quality runs in sympathy with the wind gusting. At a
wind/tree null point, the picture locks and blocks up like Sinclair
Spectrum graphics. On analogue there's no noticeable change in
picture quality.

Thats more than likely the weaker digital signals suffering
attenuation..
--
Tony Sayer

In article , The Natural Philosopher
scribeth thus
tony sayer wrote:
are in general not far away for TV, its the multipath and the other
stations that get collected that cause problems on digital in my
experience.
Usually in Digital reception they add together which is one of the good
things about digital transmission...

Ok I have a distribution booster, but the set top boxes always report
good signal levels, but poor signal quality when I have 'issues'


I ought to replace teh analogue with a good log wotsit in the loft..
May not be necessary unless you have a very wide band of frequencies to
deal with. I bet the "loft" has a load of chicken type wire therein?...
Nah. The aerial is under the tiled pseudo extension the bloody planners
made me put in..

straight through the tiles sideways to sudbury..

Where did you get all these "ghosts" you referred to earlier?..

In laws setup. somewhere else.


If you mean multipath

I suffer from other stations presumably sur le continent.

If I lived where you do I'd have gone Freesat years ago;!..

Like we have here and fine it is too..





--
Tony Sayer

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember PeterC
saying something like:

I'd love to have something in the loft, but at 43km (Oxford - Sandy is the
same distance but there's a bloody gert railway embankment 100m away in
that direction) and pointing through the gable wall...

I recently mounted an old 90cm sq MMDS dish in my attic space, pointing
to a tx ~30 miles away. At the focal point is a looped dipole with a
300/75ohm matcher off the back of an old portable. It works bloody well
too, inside a lined roof, with digital signals coming in very cleanly
and strong.
This is the kind of thing...
http://tinyurl.com/mmds-90cm

On Mon, 14 Jun 2010 22:30:34 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember PeterC
saying something like:

I'd love to have something in the loft, but at 43km (Oxford - Sandy is the
same distance but there's a bloody gert railway embankment 100m away in
that direction) and pointing through the gable wall...

I recently mounted an old 90cm sq MMDS dish in my attic space, pointing
to a tx ~30 miles away. At the focal point is a looped dipole with a
300/75ohm matcher off the back of an old portable. It works bloody well
too, inside a lined roof, with digital signals coming in very cleanly
and strong.
This is the kind of thing...
http://tinyurl.com/mmds-90cm

As you mention the lined roof, was it pointing (can a dish 'point'?)
through the roof?
Mine would have to be straight through the gable wall - cavity wall+rock
wool.
--
Peter.
2x4 - thick plank; 4x4 - two of 'em.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember PeterC
saying something like:

As you mention the lined roof, was it pointing (can a dish 'point'?)
through the roof?
Mine would have to be straight through the gable wall - cavity wall+rock
wool.

Ah well. Possibly too much thickness. The roof here is a layer of
asbestos tiles and an inner lining of cementitious fibreboard. All at
45deg, so effectively thicker than it seems.

Otoh...

At first floor level, I find that a set top aerial is useable indoors
(same tx) inside 10" of solid block (rear wall), but an extra 5" of
block and re-inforcing rods (internal dividing wall) renders it all but
useless.

If you could lay hands on a dish (doesn't have to be MMDS, an old 90cm
sat dish will do) and give it a go for next to no cost.

My reasoning was that the extra gain of the dish will compensate for the
attenuation and so it's proven to be, at least on the roof structure.

On Tue, 15 Jun 2010 13:30:28 +0100, Grimly Curmudgeon wrote:

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember PeterC
saying something like:

As you mention the lined roof, was it pointing (can a dish 'point'?)
through the roof?
Mine would have to be straight through the gable wall - cavity wall+rock
wool.

Ah well. Possibly too much thickness. The roof here is a layer of
asbestos tiles and an inner lining of cementitious fibreboard. All at
45deg, so effectively thicker than it seems.

Otoh...

At first floor level, I find that a set top aerial is useable indoors
(same tx) inside 10" of solid block (rear wall), but an extra 5" of
block and re-inforcing rods (internal dividing wall) renders it all but
useless.

If you could lay hands on a dish (doesn't have to be MMDS, an old 90cm
sat dish will do) and give it a go for next to no cost.

My reasoning was that the extra gain of the dish will compensate for the
attenuation and so it's proven to be, at least on the roof structure.

Good tip, thanks. I'll see if I can find something - when I get a tuit!
(with the switchover next year it seems like ages yet).
--
Peter.
2x4 - thick plank; 4x4 - two of 'em.