whats the minimum seperating distance between two Freeview aerials?

I am about to mount my metallic tree against my new house's gable end.

I live in an area that is served by 4 different freeview transmitters..
I have proved this tonight by waving an aerial around in the loft and
getting reliable reception from all four Tx'es

So theoretically, I can put up a log periodic aerial on each of the 4
transmitters on the same pole. Now the question is whats the minimum
spacing between them in both the horizontal and vertical directions so
that they no not affect each other?

There are a number of houses here with 2 aerials, presumably from
analogue days and for picking up different BBC1 and/or ITV regions.

The aerials will be feeding a Televes Avant 5 which has three TV aerial
inputs and then the whole lot fed into a 16 output multiswitch.


Stephen.

On 09/07/2012 23:21, Stephen H wrote:
I am about to mount my metallic tree against my new house's gable end.

I live in an area that is served by 4 different freeview transmitters..
I have proved this tonight by waving an aerial around in the loft and
getting reliable reception from all four Tx'es

So theoretically, I can put up a log periodic aerial on each of the 4
transmitters on the same pole. Now the question is whats the minimum
spacing between them in both the horizontal and vertical directions so
that they no not affect each other?


If ye are going to all that to get alternative programmes, why not just
put up a freesat dish?

--
Adrian C

Stephen H wrote:
So theoretically, I can put up a log periodic aerial on each of the 4
transmitters on the same pole. Now the question is whats the minimum
spacing between them in both the horizontal and vertical directions so
that they no not affect each other?

It will depend on the antenna gain. You need to replace "do not affect"
by "have negligible affect".

Unfortunately the easiest figure to find will be for phased arrays,
where they all point to the same transmitter. The tolerable separation
for different directions is likely to smaller than that for a phased array.

"Stephen H" wrote in message
...
I am about to mount my metallic tree against my new house's
gable end.

I live in an area that is served by 4 different freeview
transmitters.. I have proved this tonight by waving an aerial
around in the loft and getting reliable reception from all four
Tx'es

So theoretically, I can put up a log periodic aerial on each of
the 4 transmitters on the same pole. Now the question is whats
the minimum spacing between them in both the horizontal and
vertical directions so that they no not affect each other?

There are a number of houses here with 2 aerials, presumably
from analogue days and for picking up different BBC1 and/or ITV
regions.

The aerials will be feeding a Televes Avant 5 which has three
TV aerial inputs and then the whole lot fed into a 16 output
multiswitch.



I know this might be a silly question, but why would you want
four different stations. I would suspect you are unlikely to get
more than two different regions so this suggests that two of the
four stations are relays. If their main feed station went off so
would they so what is the point.

Apart from the local news and weather and the odd opt-out there
is very little difference between regions these days anyway.

You could of course use a rotator?


--
Woody

harrogate three at ntlworld dot com

On 10/07/2012 08:04, Woody wrote:
"Stephen wrote in message

I know this might be a silly question, but why would you want
four different stations. I would suspect you are unlikely to get
more than two different regions so this suggests that two of the
four stations are relays. If their main feed station went off so
would they so what is the point.

Doesn't SH live near Northampton ?

Oxford
Sandy
Sutton C
Crystal P

That's four regions in my book :-)

Apart from the local news and weather and the odd opt-out there
is very little difference between regions these days anyway.

Quite !! and as pointed out why not just Freesat anyway ?

--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk

On Tue, 10 Jul 2012 08:07:53 +0100, Mark Carver
wrote:

On 10/07/2012 08:04, Woody wrote:
"Stephen wrote in message

I know this might be a silly question, but why would you want
four different stations. I would suspect you are unlikely to get
more than two different regions so this suggests that two of the
four stations are relays. If their main feed station went off so
would they so what is the point.

Doesn't SH live near Northampton ?

Oxford
Sandy
Sutton C
Crystal P

That's four regions in my book :-)

Apart from the local news and weather and the odd opt-out there
is very little difference between regions these days anyway.

Quite !! and as pointed out why not just Freesat anyway ?

In the 'good old days' of independent ITV companies it used to be an
interesting exercise to get different stations. Now it's pointless.
Still I expect the OP's new neighbours will admire his 'metallic
tree.'

On Mon, 09 Jul 2012 23:21:17 +0100, Stephen H
wrote:

I am about to mount my metallic tree against my new house's gable end.

I live in an area that is served by 4 different freeview transmitters..
I have proved this tonight by waving an aerial around in the loft and
getting reliable reception from all four Tx'es

So theoretically, I can put up a log periodic aerial on each of the 4
transmitters on the same pole. Now the question is whats the minimum
spacing between them in both the horizontal and vertical directions so
that they no not affect each other?

There are a number of houses here with 2 aerials, presumably from
analogue days and for picking up different BBC1 and/or ITV regions.

The aerials will be feeding a Televes Avant 5 which has three TV aerial
inputs and then the whole lot fed into a 16 output multiswitch.

Setting aside the other comments for a moment, if you really want to
do this the best way is to stack them vertically, not horizontally
spaced. If they are all pointing in different directions there will
not be a great deal of interaction between them.

In article , David Woolley
wrote:
Stephen H wrote:
So theoretically, I can put up a log periodic aerial on each of the 4
transmitters on the same pole. Now the question is whats the minimum
spacing between them in both the horizontal and vertical directions so
that they no not affect each other?

It will depend on the antenna gain.

I'd be interested to see what value for spacing Bill or other riggers
suggest. Failing that, here are ways to make a guess...

1) The gain of the antenna types normally used here tends to increase with
the length from reflector to the front director. So a spacing bigger than
the length might be a fair choice.

2) Look up the gain of the antenna. Then use that and the wavelength to
work out the effective area. Then take the sqare root of that to get a
diameter. Then use that as your scale length for minimum spacing.

Failing that, I'd go with 'use a rotator or just choose one TX' as others
suggest. :-)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article ,
lid scribeth thus
On Tue, 10 Jul 2012 08:07:53 +0100, Mark Carver
wrote:

On 10/07/2012 08:04, Woody wrote:
"Stephen wrote in message

I know this might be a silly question, but why would you want
four different stations. I would suspect you are unlikely to get
more than two different regions so this suggests that two of the
four stations are relays. If their main feed station went off so
would they so what is the point.

Doesn't SH live near Northampton ?

Oxford
Sandy
Sutton C
Crystal P

That's four regions in my book :-)

Apart from the local news and weather and the odd opt-out there
is very little difference between regions these days anyway.

Quite !! and as pointed out why not just Freesat anyway ?

In the 'good old days' of independent ITV companies it used to be an
interesting exercise to get different stations. Now it's pointless.
Still I expect the OP's new neighbours will admire his 'metallic
tree.'

The days of interesting differing regional TV are long gone much the
same for FM hardly worth the bother of a rotator anymore;(...

--
Tony Sayer

On 10/07/12 08:04, Woody wrote:
"Stephen wrote in message
...
I am about to mount my metallic tree against my new house's
gable end.

I live in an area that is served by 4 different freeview
transmitters.. I have proved this tonight by waving an aerial
around in the loft and getting reliable reception from all four
Tx'es

So theoretically, I can put up a log periodic aerial on each of
the 4 transmitters on the same pole. Now the question is whats
the minimum spacing between them in both the horizontal and
vertical directions so that they no not affect each other?

There are a number of houses here with 2 aerials, presumably
from analogue days and for picking up different BBC1 and/or ITV
regions.

The aerials will be feeding a Televes Avant 5 which has three
TV aerial inputs and then the whole lot fed into a 16 output
multiswitch.



I know this might be a silly question, but why would you want
four different stations. I would suspect you are unlikely to get
more than two different regions so this suggests that two of the
four stations are relays. If their main feed station went off so
would they so what is the point.

Apart from the local news and weather and the odd opt-out there
is very little difference between regions these days anyway.

You could of course use a rotator?

If he's high-up in Northamptonshire, he can probably pick up at least 3 or 4
of Crystal Palace, Waltham, Sandy Heath, Oxford and Sutton Coldfield. None of
those are relays as far as I know