whats the minimum seperating distance between two Freeview aerials?

Jim Lesurf wrote:

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

If it's just four logs, I'd try to have them in an order on the mast
that means no adjacent ones are pointing in similar directions. Then you
can have them about 18" apart and they'll be fine.

How are you combining the signals? If you are switching rather than
combining, put a low gain masthead amp on each aerial and you can then
use a simple rotary switch to select, because the lack of DC to the
aerial not in use will effectively isolate them and there will be no
phasing effects. If you use a really small wafer switch and do the
connections neatly and put it in a diecast box the losses are very low.

Bill

Just to add a couple of points not yet made.
Your additional regions will be added in the 800's, depends on the freeview
box, but the older ones like Thompson PVR are really difficult, they scan by
frequency and add the lowest first (a problem in North of Cumbria where
Scottish channels become the default !)
I have antenna's for Bilsdale and Pontop Pike (Analogue leftover to get Tyne
Tees North and South !) - I use Satellite now.
The point is that when my local (Caldbeck) chimney mounted antenna got water
in, and failed, I plugged in the combined analogue antenna feed, and get
great Caldbeck digital reception.
You might want to consider grouped aerials rather than wideband to reduce
potential interference.

Regards
Colin

"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.


Stephen.

On 10/07/2012 08:07, 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 ?


Crystal Palace is challenging here, but Waltham is OK.

Hannington does make an appearance here too.

But Mark is correct, I live in Northampton on a hill and I can now get
Waltham, Oxford, Sandy Heath and Oxford.

Dallington Park is a No- no here as my house despite being only 2 miles
away. Dally Park is a relay of Sandy Heath and my house is actually
geographically higher than the tip of the Dally park tower/mast

On 10/07/2012 10:38, tony sayer wrote:
In ,
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;(...


Well, The reason for an omni directional FM aerial is to get the local
radio from Oxford (BBC OXford etc), Northampton (BBC northampton etc),
Bow Brickhill ( BBC 3 counties and Bucks radio etc), Sutton Coldifeld
(BRMB etc) and Waltham (BBC Leicester etc)

On 10/07/2012 13:36, Bill Wright wrote:
Jim Lesurf wrote:

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

If it's just four logs, I'd try to have them in an order on the mast
that means no adjacent ones are pointing in similar directions. Then you
can have them about 18" apart and they'll be fine.

How are you combining the signals? If you are switching rather than
combining, put a low gain masthead amp on each aerial and you can then
use a simple rotary switch to select, because the lack of DC to the
aerial not in use will effectively isolate them and there will be no
phasing effects. If you use a really small wafer switch and do the
connections neatly and put it in a diecast box the losses are very low.

Bill

I am now the proud owner of 4 Televes Avant 5's. They were all sold to
be with pulsing PSU problems which was fixed by yours truly using 5p
worth of 22uF capacitor....

They can process 10 UHF channels over 3 UHF aerial inputs...... so use a
couple of these and combine theri outputs prior to feeding the 2
multiswitches.

Stephen

On 10/07/2012 17:23, cmwb wrote:
Just to add a couple of points not yet made.

Your additional regions will be added in the 800's, depends on the freeview
box, but the older ones like Thompson PVR are really difficult, they scan by
frequency and add the lowest first (a problem in North of Cumbria where
Scottish channels become the default !)

Yes I am aware of this, and am happy to have channels in the 800's

I have antenna's for Bilsdale and Pontop Pike (Analogue leftover to get Tyne
Tees North and South !) - I use Satellite now.

OK

The point is that when my local (Caldbeck) chimney mounted antenna got water
in, and failed, I plugged in the combined analogue antenna feed, and get
great Caldbeck digital reception.

Uh huh.

You might want to consider grouped aerials rather than wideband to reduce
potential interference.

All duly noted. I picked up 4 brand new Log periodics for just 4 quid in
total. I also picked up 4 UHF 10 channel processors\combiners (Televes
Avant 5) that can do the filtering and combining necessary with signals
coming in from 3 UHF aerials so I can use LP's rather than grouped aerials.

Stephen.

Regards
Colin

On 10/07/2012 18:36, Stephen H wrote:
On 10/07/2012 08:07, 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 ?


Crystal Palace is challenging here, but Waltham is OK.

Hannington does make an appearance here too.

But Mark is correct, I live in Northampton on a hill and I can now get
Waltham, Oxford, Sandy Heath and Oxford.

Dallington Park is a No- no here as my house despite being only 2 miles
away. Dally Park is a relay of Sandy Heath and my house is actually
geographically higher than the tip of the Dally park tower/mast


and Sutton Coldfield.

On 10/07/2012 18:50, Stephen H wrote:
But Mark is correct, I live in Northampton on a hill and I can now get
Waltham, Oxford, Sandy Heath and Oxford.

snip

and Sutton Coldfield.

Is that what the second Oxford was?

Andy

In article , Stephen H
scribeth thus
On 10/07/2012 17:23, cmwb wrote:
Just to add a couple of points not yet made.

Your additional regions will be added in the 800's, depends on the freeview
box, but the older ones like Thompson PVR are really difficult, they scan by
frequency and add the lowest first (a problem in North of Cumbria where
Scottish channels become the default !)

Yes I am aware of this, and am happy to have channels in the 800's

I have antenna's for Bilsdale and Pontop Pike (Analogue leftover to get Tyne
Tees North and South !) - I use Satellite now.

OK

The point is that when my local (Caldbeck) chimney mounted antenna got water
in, and failed, I plugged in the combined analogue antenna feed, and get
great Caldbeck digital reception.

Uh huh.

You might want to consider grouped aerials rather than wideband to reduce
potential interference.

All duly noted. I picked up 4 brand new Log periodics for just 4 quid in
total.

What make were they?.

I also picked up 4 UHF 10 channel processors\combiners (Televes
Avant 5) that can do the filtering and combining necessary with signals
coming in from 3 UHF aerials so I can use LP's rather than grouped aerials.

Stephen.

Regards
Colin




--
Tony Sayer

On 10/07/2012 20:04, tony sayer wrote:
In , Stephen H
scribeth thus
On 10/07/2012 17:23, cmwb wrote:
Just to add a couple of points not yet made.

Your additional regions will be added in the 800's, depends on the freeview
box, but the older ones like Thompson PVR are really difficult, they scan by
frequency and add the lowest first (a problem in North of Cumbria where
Scottish channels become the default !)

Yes I am aware of this, and am happy to have channels in the 800's

I have antenna's for Bilsdale and Pontop Pike (Analogue leftover to get Tyne
Tees North and South !) - I use Satellite now.

OK

The point is that when my local (Caldbeck) chimney mounted antenna got water
in, and failed, I plugged in the combined analogue antenna feed, and get
great Caldbeck digital reception.

Uh huh.

You might want to consider grouped aerials rather than wideband to reduce
potential interference.

All duly noted. I picked up 4 brand new Log periodics for just 4 quid in
total.

What make were they?.

Antiference, my workplace were having a clear out and staff were allowed
to purchase the surplus stock.....


I also picked up 4 UHF 10 channel processors\combiners (Televes
Avant 5) that can do the filtering and combining necessary with signals
coming in from 3 UHF aerials so I can use LP's rather than grouped aerials.

Stephen.

Regards
Colin