How do profesional riggers "point" an aerial.

Nick Yarrow wrote:
"soup" wrote in message .uk...
From here it is 226 degrees to the transmitter, if (when) I get the
"profesionals" in will they point the aerial at 226 using a compass
or do they have some sort of meter that measures maximum signal
and they wiggle the aerial (after roughly aligning it either with a
compass or even by just seeing what direction all the aerials about
point) until they get a max signal.

An amateur solution is to use a mobile phone (with free/ available
minutes!) One person sits and watches the TV (i.e. daughter in my
case) with one phone; me up ladder on my mobile (with hands-free)
turning aerial. Daughter then changes channels and reports on quality
of pictures. Only drawback is when she gets more interested in content
than quality (i.e. strongest signal.)

Simpler to take a TFT TV with you and rig it up so you can see it
while wiggling the aerial. In the case of Freeview you may even be
able to watch a signal strength bar while wiggling the aerial.

--
Chris Green

Simpler to take a TFT TV with you and rig it up so you can see it
while wiggling the aerial. In the case of Freeview you may even be
able to watch a signal strength bar while wiggling the aerial.


Sorry guys. I've been reading all this and I have to say that you can't align
an aerial properly by looking at the picture on a TV set. For analogue the AGC
hides most of the signal strength variations. If you really have to do this use
an 18dB attenuator. The trouble then is that enough signal can enter the TV set
directly to make your observations invalid.
Aligning an aerial is about finding the position and orientation that gives the
absolute best signal/noise ratio, even when lesser locations give an apparently
perfect picture.

Bill

Bill wrote:
Simpler to take a TFT TV with you and rig it up so you can see it
while wiggling the aerial. In the case of Freeview you may even be
able to watch a signal strength bar while wiggling the aerial.


Sorry guys. I've been reading all this and I have to say that you can't align
an aerial properly by looking at the picture on a TV set. For analogue the AGC
hides most of the signal strength variations. If you really have to do this use
an 18dB attenuator. The trouble then is that enough signal can enter the TV set
directly to make your observations invalid.
Aligning an aerial is about finding the position and orientation that gives the
absolute best signal/noise ratio, even when lesser locations give an apparently
perfect picture.

I did say (for FreeView) to "watch a signal strength bar". It may
well not be quite so easy/quick/accurate as a signal strength meter
but it certainly made the job possible for me. The Daewoo STB shows
signal strength, S/N ratio and 'digital quality' (whatever that may
be) on a single screen which makes watching what happens when you
wiggle the aerial fairly easy to see. There doesn't seem to be much
delay between moving the aerial and seeing any effect.

As I'm only setting up the aerial for use with said Daewoo STB it
matters not at all to me what the bars mean quantitively, as long as
the Daewoo box thinks it's good then that's all I need.

The only problem I found was optimising the aerial position across the
different multiplexes and, unless you have several signal strength
meters, I think that problem would be the same with a 'proper' meter.

--
Chris Green

I did say (for FreeView) to "watch a signal strength bar".

Oh yes, that's fair enough. You might find that an attenuator makes this
easier, since the signal strength/quality bars are most likely compressed at
the top, or don't register any difference at all above a certain level. I have
seen some that go into the green with any signal from mediocre to massive.

Bill

On 25 Oct 2004 11:42:44 GMT, o (Bill) wrote:

| Simpler to take a TFT TV with you and rig it up so you can see it
| while wiggling the aerial. In the case of Freeview you may even be
| able to watch a signal strength bar while wiggling the aerial.
|
|
| Sorry guys. I've been reading all this and I have to say that you can't align
| an aerial properly by looking at the picture on a TV set. For analogue the AGC
| hides most of the signal strength variations. If you really have to do this use
| an 18dB attenuator. The trouble then is that enough signal can enter the TV set
| directly to make your observations invalid.

But a TV set and a STB are all we have available. :-(

| Aligning an aerial is about finding the position and orientation that gives the
| absolute best signal/noise ratio, even when lesser locations give an apparently
| perfect picture.

Using equipment which we poor amateurs have not got and can not reasonably
afford :-(

--
Dave F

In message
Dave Fawthrop wrote:

On 25 Oct 2004 11:42:44 GMT, o (Bill) wrote:

| Aligning an aerial is about finding the position and orientation that
| gives the absolute best signal/noise ratio, even when lesser locations
| give an apparently perfect picture.

Using equipment which we poor amateurs have not got and can not reasonably
afford :-(

Er, that's why you hire a professional to come and do it for you...

--
Kevin Bracey, Principal Software Engineer
Tematic Ltd Tel: +44 (0) 1223 503464
182-190 Newmarket Road Fax: +44 (0) 1728 727430
Cambridge, CB5 8HE, United Kingdom WWW: http://www.tematic.com/

On Mon, 25 Oct 2004 16:14:30 +0100, Kevin Bracey
wrote:

| In message
| Dave Fawthrop wrote:
|
| On 25 Oct 2004 11:42:44 GMT, o (Bill) wrote:
|
| | Aligning an aerial is about finding the position and orientation that
| | gives the absolute best signal/noise ratio, even when lesser locations
| | give an apparently perfect picture.
|
| Using equipment which we poor amateurs have not got and can not reasonably
| afford :-(
|
| Er, that's why you hire a professional to come and do it for you...

But professionals cost *money* :-(

--
Dave F

On Mon, 25 Oct 2004 19:01:46 +0100, Dave Fawthrop wrote:

On Mon, 25 Oct 2004 16:14:30 +0100, Kevin Bracey
wrote:

| In message
| Dave Fawthrop wrote:
|
| On 25 Oct 2004 11:42:44 GMT, o (Bill) wrote:
|
| | Aligning an aerial is about finding the position and orientation that
| | gives the absolute best signal/noise ratio, even when lesser locations
| | give an apparently perfect picture.
|
| Using equipment which we poor amateurs have not got and can not reasonably
| afford :-(
|
| Er, that's why you hire a professional to come and do it for you...

But professionals cost *money* :-(

And you may well get a cowboy ;-(
--
Phil Cook looking north over the park to the "Westminster Gasworks"

Phil Cook wrote:

On Mon, 25 Oct 2004 19:01:46 +0100, Dave Fawthrop wrote:


On Mon, 25 Oct 2004 16:14:30 +0100, Kevin Bracey
wrote:

| In message
| Dave Fawthrop wrote:
|
| On 25 Oct 2004 11:42:44 GMT, o (Bill) wrote:
|
| | Aligning an aerial is about finding the position and orientation that
| | gives the absolute best signal/noise ratio, even when lesser locations
| | give an apparently perfect picture.
|
| Using equipment which we poor amateurs have not got and can not reasonably
| afford :-(
|
| Er, that's why you hire a professional to come and do it for you...

But professionals cost *money* :-(


And you may well get a cowboy ;-(

Watch out. I'm rapidly trying to reduce personal weight so that I can
safely climb peoples roofs. Is there a CAI recommended guideline on
this. What should I aim for? 10 Stone? :-)

--

Adrian C

"harrogate2" wrote in message
...

"Mat Overton" wrote in message
o.uk...
| Before doing it, just check that the aerial cable is not live
by some
| means or other... -esp. if using an aluminium ladder!
|
| On that point, what is the power output of a masthead amp power
supply.....
| ouch!

Only 12 V which will not kill you from electric shock, only kills
you if
it
makes you fall off a ladder.

Yes but the voltage isn't the issue, it's the wattage that hurts!



In that case I'll keep away from you and your place if you don't mind.

It is the CURRENT that hurts - 10mA will hurt, 30mA across the heart
will kill. Skin resistance varies according to person, skin moisture
level, etc etc. I once knew a chap who could get a minor shock off
24V, but for most people something rather higher - nearer four
figures - is needed under normal circumstances.


--
Woody






Out of interest, you have just made the point that it is the wattage that
matters! You can't get the amps without the volts. (Ohm's Law)

Rickey