[OT] Best FM aerial?

In article , David W.E. Roberts
writes

"tony sayer" wrote in message
news snip
So If I were U I'd mount it horizontally as its much less fuss and
windload, especially on that mast you've got!..

One thing still puzzles me - I can't see much difference in the wind loading
if the dipole is horizontal or vertical.
I presume that sideways on there would be some more loading when the dipole
is vertical, and this would be enhanced by the long lever the dipole is
mounted on, but given the relatively slim profile of the dipole when the
wind is at right angles, is this going to be a major issue?


Well the stand-off arm is adding the overall load and you have a "twist"
element added in now with that load on the stand off adding a rotation
element. Thats may not have that much effect but its an added load on
the chimney mountings.....

--
Tony Sayer

In article , Kev
writes
tony sayer said the following on 14/01/2005 23:00:
The following are Vertical Only (The list is from March-2004 so some new
Vertical only may have come on stream, and some may now be mixed) :

90 BBC National TXs


Eh?, Which ones?..


Cirencester Town SP023021

Few stations demolished


Woolmoor SE457881


I must admit I'm surprised that there are that many still single
vertical only


I was referring to BBC stations. Most all of those in your list are
SALLIE licensees which are quite low power often 100 watts or less.
And a lot of these have now been very generously allocated another 100
watts in the Horiz

As i said the list was from 10 months ago (Same reason High Peak is
missing), quite possibly from month older OFCOM data too.

Yes almost all small ILR's have now been allocated some power in the
Horizontal. I know of Six in that list that have been or are being
converted to mixed.

Unless you are getting one of the three horizontal only BBC relays, need
the directional gain or there is some specific reason why you need
horizontal (i.e. at my former address BBC Sheffield 94.7 could only be
recived with the aerial mounted horizontally in the loft, at an address
before that BRMB was only listenable with the aerial horizontal due to
the higher powered Trent FM) vertical would give you the largest number
of stations wouldn't it? - espcially considering a number of Regionals
(Galaxy 105, Real Radio 106-108) are much higher powered in the vertical
plane than the horizontal.


Yes but one of the main reasons for having mixed is the reduction in
multipath fading this brings about in built up areas due to distortion
of the polarisation due to reflections etc.

Apart from that, show any small ILR manager that he's getting double the
power and their eyes immeaditly light up thinking that they will now
have double the coverage, and perhaps be turning in a profit!.

Not forgetting any RSL's that you might want to listen to.

I hope the last one round this way improves a shade from last year and
is not full of chav's wanting to give their mates a "SHOUT"....

--
Tony Sayer

On Fri, 14 Jan 2005 23:16:56 +0000, tony sayer
wrote:

In article , Marky P
writes
On Fri, 14 Jan 2005 21:54:03 -0000, Arthur wrote:

On Fri, 14 Jan 2005 20:49:40 -0000, David W.E. Roberts
wrote:

Why are you bothering to mount the FM folded dipole Vertical, is there
anything around your area thats worth listening to thats vertical
polarisation only then?....

Just following the instructions on the box :-)

So what is best?
Vertical, horizontal, sloping?

Not sure what benefit I would get from mounting it in any other
orientation
unless the signals are e.g. horizontal only.


It's fine the way it is, David

Arthur

It's a dipole, designed for omnidirectional reception & designed for
mounting vertically. I would only mount it horizontally if I was
trying to reject signals at 90 degrees to the desired Tx. The long
stand-off pole is unneccesary, but if it gives no problems, leave it.

Marky P.


A di-pole isn't designed for Vertical only at all. The directional
pattern is set by the polarisation and mounting method. The real problem
is when its mounted close to its support mast and the lack of a balun
compounds the problem even further. I've modelled these with an aerial
pattern designer and they ain't all that good when too close to a
support structure.

Having said that their much better than that "Halo" abortion!...

I'd be a bit concerned with the windload on the original posters piccy

What I really meant was that they are sold as being omnidirectional,
therefore being mounted vertically. Nothing stopping you mounting it
how you like, of course. Mine is too close to the mast, really. I
just stuck it on 'as is' using the short arm. Performs very well, but
wondered if it was worth extending the mounting arm or not.

Marky P.

What I really meant was that they are sold as being omnidirectional,
therefore being mounted vertically. Nothing stopping you mounting it
how you like, of course. Mine is too close to the mast, really. I
just stuck it on 'as is' using the short arm. Performs very well, but
wondered if it was worth extending the mounting arm or not.

Marky P.

Well at least you have an FM aerial Depends on what U want to pull in.
If its stuff from further afield then mounting a Yagi vertically is
rather more fun;(
--
Tony Sayer

On Sat, 15 Jan 2005 20:59:57 +0000, tony sayer
wrote:

What I really meant was that they are sold as being omnidirectional,
therefore being mounted vertically. Nothing stopping you mounting it
how you like, of course. Mine is too close to the mast, really. I
just stuck it on 'as is' using the short arm. Performs very well, but
wondered if it was worth extending the mounting arm or not.

Marky P.

Well at least you have an FM aerial Depends on what U want to pull in.
If its stuff from further afield then mounting a Yagi vertically is
rather more fun;(

Got bored of that a few years ago, when all ILR's were taken over by
GLR:-(
You may recall me mentioning before that I used to have a Ron Smith
Galaxie 26 on me roof, but that eventually threatened to bring the
wall down.

Anyway, my current dipole pulls in distant stuff quite well. I'm in
Bedford & get pretty good reception from Oxford, Northampton &
Cambridge (though the mast attenuates the Cambridge signals a bit) &
also BBC London ain't bad in mono.

Marky P.

tony sayer wrote:

I personally have only used cable ties once on airspaced coax, and after


that experience went back to duct tape which seems to last forever if
applied carefully. I note in Bill's recently posted picture about Emley
that he uses tape on his professional installations. No doubt he will
tell you what sort it is.




Tapes fine on domestic installs but pro ones where such as RG214 and
LDF4-50 etc are in use, cable ties are more the done thing....



No, thats not the case. "Pro installations" use one or two-part cable
clamps fixed to a stainless steel stud.
RG214 is never used as a feeder in these cases.
A

tony sayer wrote:
In article , Kev

The following are Vertical Only (The list is from March-2004 so some new
Vertical only may have come on stream, and some may now be mixed) :
90 BBC National TXs

Eh?, Which ones?..

Cirencester Town SP023021

Few stations demolished

Woolmoor SE457881


I must admit I'm surprised that there are that many still single
vertical only

Most of those in Kev's list have come on line in the last 10-15 years,
seems to be Beeb/CCI policy to use VP only on new FM relay stations.

Aerials are sometimes just a simple dipole like at Luddenden:-

http://tx.mb21.co.uk/gallery/luddenden.asp

Or a magnificent double stack log periodic beam here on my doorstep

http://tx.mb21.co.uk/gallery/basingstoke.asp

I really must get out more :-)

In article , Andy Dee
writes
tony sayer wrote:

I personally have only used cable ties once on airspaced coax, and after


that experience went back to duct tape which seems to last forever if
applied carefully. I note in Bill's recently posted picture about Emley
that he uses tape on his professional installations. No doubt he will
tell you what sort it is.




Tapes fine on domestic installs but pro ones where such as RG214 and
LDF4-50 etc are in use, cable ties are more the done thing....



No, thats not the case. "Pro installations" use one or two-part cable
clamps fixed to a stainless steel stud.
RG214 is never used as a feeder in these cases.
A

Well if thats coming down a 1000 foot tower or similar then yes, but
I've seen a lot of uses where cable ties only have been used. Depends on
who's looking over the aerial riggers shoulder.

Beg yer pardon RG213 is used in some instances, not all.....
--
Tony Sayer

In article , Marky P
writes
On Sat, 15 Jan 2005 20:59:57 +0000, tony sayer
wrote:

What I really meant was that they are sold as being omnidirectional,
therefore being mounted vertically. Nothing stopping you mounting it
how you like, of course. Mine is too close to the mast, really. I
just stuck it on 'as is' using the short arm. Performs very well, but
wondered if it was worth extending the mounting arm or not.

Marky P.

Well at least you have an FM aerial Depends on what U want to pull in.
If its stuff from further afield then mounting a Yagi vertically is
rather more fun;(

Got bored of that a few years ago, when all ILR's were taken over by
GLR:-(

Yep pity but its not local radio as we once knew it;(

You may recall me mentioning before that I used to have a Ron Smith
Galaxie 26 on me roof, but that eventually threatened to bring the
wall down.

Yes I had one of his 23's once but the Fuba UK8 outperformed it...

Anyway, my current dipole pulls in distant stuff quite well. I'm in
Bedford & get pretty good reception from Oxford, Northampton &
Cambridge (though the mast attenuates the Cambridge signals a bit)

Not boring olde waydio Cambs for the brain dead;?....
&
also BBC London ain't bad in mono.

Has its moments...

Marky P.


--
Tony Sayer

In article , Mark Carver
writes
tony sayer wrote:
In article , Kev

The following are Vertical Only (The list is from March-2004 so some new
Vertical only may have come on stream, and some may now be mixed) :
90 BBC National TXs

Eh?, Which ones?..

Cirencester Town SP023021

Few stations demolished

Woolmoor SE457881


I must admit I'm surprised that there are that many still single
vertical only

Most of those in Kev's list have come on line in the last 10-15 years,
seems to be Beeb/CCI policy to use VP only on new FM relay stations.

Aerials are sometimes just a simple dipole like at Luddenden:-

http://tx.mb21.co.uk/gallery/luddenden.asp

Or a magnificent double stack log periodic beam here on my doorstep

http://tx.mb21.co.uk/gallery/basingstoke.asp

I really must get out more :-)

I'm quite surprised that they still use single plane polarisation as
I've said in another post earlier mixed is much better for use in towns
and built up areas. Not all of those relays are just out in the sticks
ones.

Suppose its cheaper, one aerial instead of two;!. The way mast and tower
rental prices are going;((((

--
Tony Sayer