On 21/07/2011 17:39, Terry Casey wrote:
In messagexaydnUEyjJtzp7XTnZ2dnUVZ7qmdnZ2d@brightvie w.com on Thu, 21 Jul
2011 15:42:44 +0100
wrote:

wrote in message news
In articleQY2dnQ7nn7MMsbXTnZ2dnUVZ8vKdnZ2d@brightvie w.com, MuddyMike
writes

wrote in message ...

Enter your postcode into http://www.wolfbane.com/cgi-bin/tvd.exe? and let
us know the transmitter, the distance to you, broadcast channel numbers
and whether it's been DSO'd. Don't worry, the .exe in the link is not a
downloadable, it executes on the server, not your comp. There's a good
link to the topography or your TX path on there too, very informative.


This is what I get, all meaningless to me. I can't make out the colour of
the endcap, will take a picture a little later then perhaps yopu can advise
if we have the right type.


That only appears to show the current situation.

http://tinyurl.com/3wfhf52

also includes the post DSO situation which shows that you will need a wideband
aerial, rather than a grouped one.

No, it shows a group K would be ideal (a K is in effect a Group A
tweaked to go up to Ch 48 rather than the typical cut off around Ch 40).
A group K will significantly outperform a wideband:

http://www.aerialsandtv.com/atvstock...ts.html#Kgroup



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In message on Sun, 24 Jul
2011 02:21:03 +0100
John Rumm wrote:

On 21/07/2011 17:39, Terry Casey wrote:
In messagexaydnUEyjJtzp7XTnZ2dnUVZ7qmdnZ2d@brightvie w.com on Thu, 21 Jul
2011 15:42:44 +0100

http://tinyurl.com/3wfhf52

also includes the post DSO situation which shows that you will need a wideband
aerial, rather than a grouped one.

No, it shows a group K would be ideal (a K is in effect a Group A
tweaked to go up to Ch 48 rather than the typical cut off around Ch 40).
A group K will significantly outperform a wideband:

http://www.aerialsandtv.com/atvstock...ts.html#Kgroup

While this thread has been under discussion, I noted that Java Jive reported on
uk.tech.digital-tv (which would have been a better place for this thread) that
he had updated his site with the latest Ofcom information.

This would appear to be one of the updates! When I checked earlier, it said K
pre DSO and W post DSO.

It now says K for post DSO as well so, assuming it is not an error, I would
agree with fitting a Group K aerial.

We are still awaiting confirmation from the OP of which group his aerial is ...

--

Terry

On 24/07/2011 18:52, Terry Casey wrote:
In messageupWdnazSiOca7rbTnZ2dnUVZ8oSdnZ2d@brightvie w.co.uk on Sun, 24 Jul
2011 02:21:03 +0100
John wrote:

On 21/07/2011 17:39, Terry Casey wrote:
In messagexaydnUEyjJtzp7XTnZ2dnUVZ7qmdnZ2d@brightvie w.com on Thu, 21 Jul
2011 15:42:44 +0100

http://tinyurl.com/3wfhf52

also includes the post DSO situation which shows that you will need a wideband
aerial, rather than a grouped one.

No, it shows a group K would be ideal (a K is in effect a Group A
tweaked to go up to Ch 48 rather than the typical cut off around Ch 40).
A group K will significantly outperform a wideband:

http://www.aerialsandtv.com/atvstock...ts.html#Kgroup

While this thread has been under discussion, I noted that Java Jive reported on
uk.tech.digital-tv (which would have been a better place for this thread) that
he had updated his site with the latest Ofcom information.

Yup, saw that...

This would appear to be one of the updates! When I checked earlier, it said K
pre DSO and W post DSO.

It now says K for post DSO as well so, assuming it is not an error, I would
agree with fitting a Group K aerial.

That would seem to concur with:

http://www.ukfree.tv/txdetail.php?a=SE553962

Low channel 23 high 46, post DSO - so a K will do it (and at that
distance be worth having)

We are still awaiting confirmation from the OP of which group his aerial is ...


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Terry Casey" wrote in message
...
In message on Sun, 24
Jul
2011 02:21:03 +0100
John Rumm wrote:

On 21/07/2011 17:39, Terry Casey wrote:
In messagexaydnUEyjJtzp7XTnZ2dnUVZ7qmdnZ2d@brightvie w.com on Thu, 21
Jul
2011 15:42:44 +0100

http://tinyurl.com/3wfhf52

also includes the post DSO situation which shows that you will need a
wideband
aerial, rather than a grouped one.

No, it shows a group K would be ideal (a K is in effect a Group A
tweaked to go up to Ch 48 rather than the typical cut off around Ch 40).
A group K will significantly outperform a wideband:

http://www.aerialsandtv.com/atvstock...ts.html#Kgroup

While this thread has been under discussion, I noted that Java Jive
reported on
uk.tech.digital-tv (which would have been a better place for this thread)
that
he had updated his site with the latest Ofcom information.

This would appear to be one of the updates! When I checked earlier, it
said K
pre DSO and W post DSO.

It now says K for post DSO as well so, assuming it is not an error, I
would
agree with fitting a Group K aerial.

We are still awaiting confirmation from the OP of which group his aerial
is ...


I did post this link to a couple of pictures of the aerial
http://share.ovi.com/album/Muddymike.Housechanges
a few days ago saying that I didn't know what it is.

Mike

In message on Mon, 25 Jul
2011 08:13:20 +0100
MuddyMike wrote:

"Terry Casey" wrote in message
...
In message on Sun, 24
Jul
2011 02:21:03 +0100
John Rumm wrote:

On 21/07/2011 17:39, Terry Casey wrote:
In messagexaydnUEyjJtzp7XTnZ2dnUVZ7qmdnZ2d@brightvie w.com on Thu, 21
Jul
2011 15:42:44 +0100

http://tinyurl.com/3wfhf52

also includes the post DSO situation which shows that you will need a
wideband
aerial, rather than a grouped one.

No, it shows a group K would be ideal (a K is in effect a Group A
tweaked to go up to Ch 48 rather than the typical cut off around Ch 40).
A group K will significantly outperform a wideband:

http://www.aerialsandtv.com/atvstock...ts.html#Kgroup

While this thread has been under discussion, I noted that Java Jive
reported on
uk.tech.digital-tv (which would have been a better place for this thread)
that
he had updated his site with the latest Ofcom information.

This would appear to be one of the updates! When I checked earlier, it
said K
pre DSO and W post DSO.

It now says K for post DSO as well so, assuming it is not an error, I
would
agree with fitting a Group K aerial.

We are still awaiting confirmation from the OP of which group his aerial
is ...


I did post this link to a couple of pictures of the aerial
http://share.ovi.com/album/Muddymike.Housechanges
a few days ago saying that I didn't know what it is.


The only way to determine that would be to measure the lengths of all the
elements - hardly practical from a picture. I thought you were going to try
getting a better view so that you could see the colour of the bung in the end
of the boom?

Ask the installer what he used - it will be interesting to see if he
understands the concept of grouped aerials. From the loops of cable visible in
your picture, it is obvious that he is not the most competent of installers ...

--

Terry

In article ,
MuddyMike wrote:
I did post this link to a couple of pictures of the aerial
http://share.ovi.com/album/Muddymike.Housechanges
a few days ago saying that I didn't know what it is.


Looks a pretty scruffy installation. Did they simply hack off an existing
aerial and fix the new one to what remained?

Brickwork can act as a reflector to RF, so ideally the aerial would be
well clear of it or anything else. My guess is they may also have used
cheap co-ax, given the standard of the workmanship.

A short pole to raise the aerial above the chimney pots and decent co-ax
(satellite stuff) would be my first thoughts. The actual lashing is poor -
the wires should take the shortest route round the stack and be parallel
to one another.

--
*Experience is something you don't get until just after you need it.*

Dave Plowman London SW
To e-mail, change noise into sound.

"Terry Casey" wrote in message
...
In message on Mon, 25
Jul
2011 08:13:20 +0100
MuddyMike wrote:

"Terry Casey" wrote in message
...
In message on Sun,
24
Jul
2011 02:21:03 +0100
John Rumm wrote:

On 21/07/2011 17:39, Terry Casey wrote:
In messagexaydnUEyjJtzp7XTnZ2dnUVZ7qmdnZ2d@brightvie w.com on Thu,
21
Jul
2011 15:42:44 +0100

http://tinyurl.com/3wfhf52

also includes the post DSO situation which shows that you will need
a
wideband
aerial, rather than a grouped one.

No, it shows a group K would be ideal (a K is in effect a Group A
tweaked to go up to Ch 48 rather than the typical cut off around Ch
40).
A group K will significantly outperform a wideband:

http://www.aerialsandtv.com/atvstock...ts.html#Kgroup

While this thread has been under discussion, I noted that Java Jive
reported on
uk.tech.digital-tv (which would have been a better place for this
thread)
that
he had updated his site with the latest Ofcom information.

This would appear to be one of the updates! When I checked earlier, it
said K
pre DSO and W post DSO.

It now says K for post DSO as well so, assuming it is not an error, I
would
agree with fitting a Group K aerial.

We are still awaiting confirmation from the OP of which group his
aerial
is ...


I did post this link to a couple of pictures of the aerial
http://share.ovi.com/album/Muddymike.Housechanges
a few days ago saying that I didn't know what it is.


The only way to determine that would be to measure the lengths of all the
elements - hardly practical from a picture. I thought you were going to
try
getting a better view so that you could see the colour of the bung in the
end
of the boom?

I have just been out with the binoculars and it looks like the plugs are
black.

Mike

"Dave Plowman (News)" wrote in message
...
In article ,
MuddyMike wrote:
I did post this link to a couple of pictures of the aerial
http://share.ovi.com/album/Muddymike.Housechanges
a few days ago saying that I didn't know what it is.


Looks a pretty scruffy installation. Did they simply hack off an existing
aerial and fix the new one to what remained?

Brickwork can act as a reflector to RF, so ideally the aerial would be
well clear of it or anything else. My guess is they may also have used
cheap co-ax, given the standard of the workmanship.

A short pole to raise the aerial above the chimney pots and decent co-ax
(satellite stuff) would be my first thoughts. The actual lashing is poor -
the wires should take the shortest route round the stack and be parallel
to one another.

The Aerial is about a foot away from the chimney stack, and the rigger did
re-use the existing lashing and pole. He pointed out the strange angle of
one lashing wire but said that as it was solid he saw no need to go to the
extra expense of replacing it all. He replaced the co-ax as far as the box
in the loft, see the new first picture at
http://share.ovi.com/album/Muddymike.Housechanges this shows the cable he
used.

Mike

In article ,
MuddyMike wrote:
Looks a pretty scruffy installation. Did they simply hack off an
existing aerial and fix the new one to what remained?

Brickwork can act as a reflector to RF, so ideally the aerial would be
well clear of it or anything else. My guess is they may also have
used cheap co-ax, given the standard of the workmanship.

A short pole to raise the aerial above the chimney pots and decent
co-ax (satellite stuff) would be my first thoughts. The actual lashing
is poor - the wires should take the shortest route round the stack and
be parallel to one another.

The Aerial is about a foot away from the chimney stack, and the rigger
did re-use the existing lashing and pole. He pointed out the strange
angle of one lashing wire but said that as it was solid he saw no need
to go to the extra expense of replacing it all. He replaced the co-ax as
far as the box in the loft, see the new first picture at
http://share.ovi.com/album/Muddymike.Housechanges this shows the cable
he used.

I'd personally not have done that. If the pole clamps were so rusty they
couldn't be undone I'd have replaced the mounting and pole so the aerial
was well clear of anything which could reflect the signal. Especially so
in a known low signal area.
The rest of the co-ax could well be introducing losses. And just because
the new co-ax is black doesn't guarantee it is decent stuff.

--
*Life is hard; then you nap

Dave Plowman London SW
To e-mail, change noise into sound.

In message on Mon, 25 Jul
2011 13:08:36 +0100
MuddyMike wrote:

"Terry Casey" wrote in message
...
In message on Mon, 25
Jul
2011 08:13:20 +0100
MuddyMike wrote:

"Terry Casey" wrote in message
...
In message on Sun,
24
Jul
2011 02:21:03 +0100
John Rumm wrote:

On 21/07/2011 17:39, Terry Casey wrote:
In messagexaydnUEyjJtzp7XTnZ2dnUVZ7qmdnZ2d@brightvie w.com on Thu,
21
Jul
2011 15:42:44 +0100

http://tinyurl.com/3wfhf52

also includes the post DSO situation which shows that you will need
a
wideband
aerial, rather than a grouped one.

No, it shows a group K would be ideal (a K is in effect a Group A
tweaked to go up to Ch 48 rather than the typical cut off around Ch
40).
A group K will significantly outperform a wideband:

http://www.aerialsandtv.com/atvstock...ts.html#Kgroup

While this thread has been under discussion, I noted that Java Jive
reported on
uk.tech.digital-tv (which would have been a better place for this
thread)
that
he had updated his site with the latest Ofcom information.

This would appear to be one of the updates! When I checked earlier, it
said K
pre DSO and W post DSO.

It now says K for post DSO as well so, assuming it is not an error, I
would
agree with fitting a Group K aerial.

We are still awaiting confirmation from the OP of which group his
aerial
is ...


I did post this link to a couple of pictures of the aerial
http://share.ovi.com/album/Muddymike.Housechanges
a few days ago saying that I didn't know what it is.


The only way to determine that would be to measure the lengths of all the
elements - hardly practical from a picture. I thought you were going to
try
getting a better view so that you could see the colour of the bung in the
end
of the boom?

I have just been out with the binoculars and it looks like the plugs are
black.


IIRC you said this is a new installation, so the colours should still be quite
clear, and I would expect you to be able to detect the difference between grey
(Group K) and black (Wideband) so that is fairly conclusive.

The various colours for each group can be seen he

http://www.aerialsandtv.com/aerials.html#aerialgroups

--

Terry

In article , MuddyMike
scribeth thus

"Terry Casey" wrote in message
...
In message on Mon, 25
Jul
2011 08:13:20 +0100
MuddyMike wrote:

"Terry Casey" wrote in message
...
In message on Sun,
24
Jul
2011 02:21:03 +0100
John Rumm wrote:

On 21/07/2011 17:39, Terry Casey wrote:
In messagexaydnUEyjJtzp7XTnZ2dnUVZ7qmdnZ2d@brightvie w.com on Thu,
21
Jul
2011 15:42:44 +0100

http://tinyurl.com/3wfhf52

also includes the post DSO situation which shows that you will need
a
wideband
aerial, rather than a grouped one.

No, it shows a group K would be ideal (a K is in effect a Group A
tweaked to go up to Ch 48 rather than the typical cut off around Ch
40).
A group K will significantly outperform a wideband:

http://www.aerialsandtv.com/atvstock...ts.html#Kgroup

While this thread has been under discussion, I noted that Java Jive
reported on
uk.tech.digital-tv (which would have been a better place for this
thread)
that
he had updated his site with the latest Ofcom information.

This would appear to be one of the updates! When I checked earlier, it
said K
pre DSO and W post DSO.

It now says K for post DSO as well so, assuming it is not an error, I
would
agree with fitting a Group K aerial.

We are still awaiting confirmation from the OP of which group his
aerial
is ...


I did post this link to a couple of pictures of the aerial
http://share.ovi.com/album/Muddymike.Housechanges
a few days ago saying that I didn't know what it is.


The only way to determine that would be to measure the lengths of all the
elements - hardly practical from a picture. I thought you were going to
try
getting a better view so that you could see the colour of the bung in the
end
of the boom?

I have just been out with the binoculars and it looks like the plugs are
black.

Mike





It looks like it nearer A group than anything else, don't reckon its a C
or that end of the band but as Steve sez very awkward to tell
accurately...
--
Tony Sayer

Although the 8 way distie amp is a good quality make, it does look dated and
it might actually be worth replacing this with a more up to date version
with F-connecotrs instead of Belling Lee and I would also replace all of the
cable between the taylor amp and the tv sockets in the house. I would expect
the wall plates will also be worth replacing with modern screened ones.

Our resident expert Bill Wright will be along one day to pass his
wisdom......

Stephen


"Dave Plowman (News)" wrote in message
...
In article ,
MuddyMike wrote:
Looks a pretty scruffy installation. Did they simply hack off an
existing aerial and fix the new one to what remained?

Brickwork can act as a reflector to RF, so ideally the aerial would be
well clear of it or anything else. My guess is they may also have
used cheap co-ax, given the standard of the workmanship.

A short pole to raise the aerial above the chimney pots and decent
co-ax (satellite stuff) would be my first thoughts. The actual lashing
is poor - the wires should take the shortest route round the stack and
be parallel to one another.

The Aerial is about a foot away from the chimney stack, and the rigger
did re-use the existing lashing and pole. He pointed out the strange
angle of one lashing wire but said that as it was solid he saw no need
to go to the extra expense of replacing it all. He replaced the co-ax as
far as the box in the loft, see the new first picture at
http://share.ovi.com/album/Muddymike.Housechanges this shows the cable
he used.

I'd personally not have done that. If the pole clamps were so rusty they
couldn't be undone I'd have replaced the mounting and pole so the aerial
was well clear of anything which could reflect the signal. Especially so
in a known low signal area.
The rest of the co-ax could well be introducing losses. And just because
the new co-ax is black doesn't guarantee it is decent stuff.

--
*Life is hard; then you nap

Dave Plowman London SW
To e-mail, change noise into sound.

Stephen wrote:

Our resident expert Bill Wright will be along one day to pass his
wisdom......

I can't remember whether Bill is resident here, or only notices
cross-posts to uk.tech.digital-tv, there have been a spate of TV threads
lately that would mostly have been better served there to start with
really ...

"Andy Burns" wrote in message
...
Stephen wrote:

Our resident expert Bill Wright will be along one day to pass his
wisdom......

I can't remember whether Bill is resident here, or only notices
cross-posts to uk.tech.digital-tv, there have been a spate of TV threads
lately that would mostly have been better served there to start with
really ...

I don't know that group, must check them out.

Mike

In message on Tue, 26 Jul
2011 07:55:33 +0100
MuddyMike wrote:

"Andy Burns" wrote in message
...
Stephen wrote:

Our resident expert Bill Wright will be along one day to pass his
wisdom......

I can't remember whether Bill is resident here, or only notices
cross-posts to uk.tech.digital-tv, there have been a spate of TV threads
lately that would mostly have been better served there to start with
really ...

I don't know that group, must check them out.


Strange - I made exactly the same comment and recommendation in an earlier
post!

As for the cables in your photograph, you can't judge the cable from the cover,
to misquote the old adage.

Take a look at this (from the afore mentioned Bill Wright):

http://www.wrightsaerials.tv/article...-quality.shtml

You might like to explore his site in depth - particularly the Rogues Gallery:

http://www.wrightsaerials.tv/roguesgallery/index.shtml

and DIY section:

http://www.wrightsaerials.tv/aerialp...iy/index.shtml

You might also find this site (in which Bill Wright also has a hand) a useful
resource as it explains the highly complex subject of Digital Switchover in
plain english:

http://www.paras.org.uk/

(Professional Aerial Riggers Against the Sharks)

--

Terry

In article , MuddyMike
scribeth thus

"Andy Burns" wrote in message
...
Stephen wrote:

Our resident expert Bill Wright will be along one day to pass his
wisdom......

I can't remember whether Bill is resident here, or only notices
cross-posts to uk.tech.digital-tv, there have been a spate of TV threads
lately that would mostly have been better served there to start with
really ...

I don't know that group, must check them out.

Mike



Yes Bill who is away IIRC at the moment, does post there but he will
tell you to make the most of what's coming off the aerial itself before
you bother with any extra amplification etc. I'd get the input signal
right i.e. correct aerial mounted up in the clear decent grade of cable
etc before bothering about the dist amp;!..
--
Tony Sayer

In message on Mon, 25 Jul
2011 22:45:29 +0100
Stephen wrote:

Although the 8 way distie amp is a good quality make, it does look dated and
it might actually be worth replacing this with a more up to date version
with F-connecotrs instead of Belling Lee and I would also replace all of the
cable between the taylor amp and the tv sockets in the house. I would expect
the wall plates will also be worth replacing with modern screened ones.

As has been said before, the greatest improvements can be obtained by starting
at the top: the correct aerial, as high as possible and connected with good
quality cable without kinks or loops, etc.

If the remainder of the installation is old, then Steve's comments are valid,
but I'd start with the cable first.

Consider trying this: buy some suitable cable - PF100 of similar (see other
posts cable types/quality) - and replace the feed to your primary outlet
except, for the moment, ignore the faceplate and connect it directly to the TV
or SetTop Box.

If you leave the old cable, faceplate, etc. in situ, with both connected to the
amplifier, you can now do a comparative test to establish the improvement
obtained from the new cable.

Now, using a back-to-back coupler, connect the aerial cable directly to the new
cable, thus bypassing the amplifier. If there is no further improvement, there
will be nothing gained by replacing the amplifier.

You could perform the amplifier check first, of course, as it is much easier to
do than running new cables ...


Our resident expert Bill Wright will be along one day to pass his
wisdom......


See other posts Bill Wright ...

--

Terry

In article ,
Terry Casey wrote:
As for the cables in your photograph, you can't judge the cable from the
cover, to misquote the old adage.

The pics show an installation done in the easiest/cheapest way for the
rigger. Not best practice especially in a low signal area. So I'd wonder
what other corners have been cut. Of course RF being a black art, you
can't guarantee how something will work by just the appearance.

However, the signal strength should have been measured at the actual TV
outlet and at the downlead.

--
*Verbs HAS to agree with their subjects *

Dave Plowman London SW
To e-mail, change noise into sound.

In message on Tue, 26 Jul 2011 10:46:05 +0100
tony sayer wrote:


Yes Bill who is away IIRC at the moment, does post there but he will
tell you to make the most of what's coming off the aerial itself before
you bother with any extra amplification etc.

From the picture, the amp only has 2dB overall gain - the rest is to compensate
for output splitter loss - so actual amp gain ~13db.

I'd get the input signal
right i.e. correct aerial mounted up in the clear decent grade of cable
etc before bothering about the dist amp;!..

Agreed!

--

Terry

In article , John
Rumm writes
On 21/07/2011 15:13, fred wrote:

The questions about DSO and grouped aerials are important. If your bod
stuck up a wideband one and the channels broadcast by your transmitter
are in the newly extended group B (low) then you have lost 4-6dB of
precious signal just like that cos wideband aerials aren't optimised
like grouped ones and favour the high end. (A wideband aerial will have
a black plug in the back of the aerial extrusion.)

Yup grouped aerials are particularly important for group A and B
transmitters - especially in difficult locations.

If you're pre-DSO then you'll be seeing a whacking improvement in signal
power when DSO happens in your area.

Indeed - we saw a rise of 19db overnight on the muxes that have just
gone full power.

Sadly not 'til Sept '12 in this case. COM3 on that transmitter is
currently on 1.5kW so at 28miles distant I doubt there's any realistic
chance of decent reception of the bemoaned missing Dave etc until DSO.

I skipped the group K suggestion as here seem to be so few about these
days and didn't think it would give enough lift anyway in this
situation.

The analogue transmitter is currently on 500kW and will become 100/50kW
at switchover so options should open up then.
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********

In article , Dave Plowman (News)
scribeth thus
In article ,
Terry Casey wrote:
As for the cables in your photograph, you can't judge the cable from the
cover, to misquote the old adage.

The pics show an installation done in the easiest/cheapest way for the
rigger. Not best practice especially in a low signal area. So I'd wonder
what other corners have been cut. Of course RF being a black art, you
can't guarantee how something will work by just the appearance.

Umm .. can I put me 'learned audio friend straight?.

RF is not a black art its just poorly understood. It obeys much the same
laws as every other thing in the universe...


However, the signal strength should have been measured at the actual TV
outlet and at the downlead.


--
Tony Sayer

In article ,
tony sayer wrote:
The pics show an installation done in the easiest/cheapest way for the
rigger. Not best practice especially in a low signal area. So I'd wonder
what other corners have been cut. Of course RF being a black art, you
can't guarantee how something will work by just the appearance.

Umm .. can I put me 'learned audio friend straight?.

;-)

RF is not a black art its just poorly understood. It obeys much the same
laws as every other thing in the universe...

It may do - but calculating accurately the effect of a nearby brick wall
might prove rather difficult. As will saying how much more loss a brown
cable has over a black one. ;-)

--
*Consciousness: That annoying time between naps.

Dave Plowman London SW
To e-mail, change noise into sound.

On 26/07/2011 12:35, fred wrote:
In article , John
Rumm writes
On 21/07/2011 15:13, fred wrote:

The questions about DSO and grouped aerials are important. If your bod
stuck up a wideband one and the channels broadcast by your transmitter
are in the newly extended group B (low) then you have lost 4-6dB of
precious signal just like that cos wideband aerials aren't optimised
like grouped ones and favour the high end. (A wideband aerial will have
a black plug in the back of the aerial extrusion.)

Yup grouped aerials are particularly important for group A and B
transmitters - especially in difficult locations.

If you're pre-DSO then you'll be seeing a whacking improvement in signal
power when DSO happens in your area.

Indeed - we saw a rise of 19db overnight on the muxes that have just
gone full power.

Sadly not 'til Sept '12 in this case. COM3 on that transmitter is
currently on 1.5kW so at 28miles distant I doubt there's any realistic
chance of decent reception of the bemoaned missing Dave etc until DSO.

Not hopeless necessarily, I am a similar distance from our transmitter
and we still have two muxes on 1.5 and 1.1kW - both of which we are
getting with decent quality.

I skipped the group K suggestion as here seem to be so few about these
days and didn't think it would give enough lift anyway in this situation.

At the lower end, a K will give a significant improvement over a wideband.

The analogue transmitter is currently on 500kW and will become 100/50kW
at switchover so options should open up then.

Indeed.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

tony sayer wrote:
In article , Dave Plowman (News)
scribeth thus
In article ,
Terry Casey wrote:
As for the cables in your photograph, you can't judge the cable from the
cover, to misquote the old adage.
The pics show an installation done in the easiest/cheapest way for the
rigger. Not best practice especially in a low signal area. So I'd wonder
what other corners have been cut. Of course RF being a black art, you
can't guarantee how something will work by just the appearance.

Umm .. can I put me 'learned audio friend straight?.

RF is not a black art its just poorly understood. It obeys much the same
laws as every other thing in the universe...

yes, but you have to see the world as if you 5 meter eyes with very poor
resolution working at very long wavelengths...:-)

And a pretty poor optic nerve that leaks..

I recall some interesting physics experiments with a giant wax 'lens'
and two microwave transceivers..



However, the signal strength should have been measured at the actual TV
outlet and at the downlead.

In article , Dave Plowman (News)
scribeth thus
In article ,
tony sayer wrote:
The pics show an installation done in the easiest/cheapest way for the
rigger. Not best practice especially in a low signal area. So I'd wonder
what other corners have been cut. Of course RF being a black art, you
can't guarantee how something will work by just the appearance.

Umm .. can I put me 'learned audio friend straight?.

;-)

RF is not a black art its just poorly understood. It obeys much the same
laws as every other thing in the universe...

It may do - but calculating accurately the effect of a nearby brick wall
might prove rather difficult. As will saying how much more loss a brown
cable has over a black one. ;-)

Well you can measure that...


--
Tony Sayer