Misguided installation

"-GB-Carpy" wrote in message
...

"Mike Henry" wrote in message
news
In , "-GB-Carpy"
wrote:

Good photos. I'm always trying to learn new things & improve, but quite
often I see things like in your photos and it amazes me how many
installers
are out there with poor knowledge. Even the basic rules of a good solid
installation seem to get ignored most of the time. Today I had to sort
out a
high gain aerial, on a 16ft mast, mounted on a single 6" chimney bracket
(welded at least - not pressed). Just silly......

For my untrained eye, could I tentatively ask what is wrong with the TV
aerial part? I can see that the radio aerial is wrong, but all I can
think
that's wrong with the TV aerial is that it's too close to the radio
aerial.

TIA :-)

Pity there's isn't a number 4, "after", picture!

TV aerial looks ok - certainly better than most!


I wonder what the metal paneling is doing to it's polar diagram, and I don't
fancy the impulses from the air conditioning motor directly underneath it.

wasn't it the birds nest and 20 deg misalignment, in conjunction with bad
tetra.
Paul T

"Doctor D" wrote in message
o.uk...

"-GB-Carpy" wrote in message
...

"Mike Henry" wrote in message
news
In , "-GB-Carpy"
wrote:

Good photos. I'm always trying to learn new things & improve, but quite
often I see things like in your photos and it amazes me how many
installers
are out there with poor knowledge. Even the basic rules of a good solid
installation seem to get ignored most of the time. Today I had to sort
out a
high gain aerial, on a 16ft mast, mounted on a single 6" chimney bracket
(welded at least - not pressed). Just silly......

For my untrained eye, could I tentatively ask what is wrong with the TV
aerial part? I can see that the radio aerial is wrong, but all I can
think
that's wrong with the TV aerial is that it's too close to the radio
aerial.

TIA :-)

Pity there's isn't a number 4, "after", picture!

TV aerial looks ok - certainly better than most!


I wonder what the metal paneling is doing to it's polar diagram, and I
don't fancy the impulses from the air conditioning motor directly
underneath it.

"Doctor D" wrote in message
o.uk...

"-GB-Carpy" wrote in message
...

"Mike Henry" wrote in message
news
In , "-GB-Carpy"
wrote:

Good photos. I'm always trying to learn new things & improve, but quite
often I see things like in your photos and it amazes me how many
installers
are out there with poor knowledge. Even the basic rules of a good solid
installation seem to get ignored most of the time. Today I had to sort
out a
high gain aerial, on a 16ft mast, mounted on a single 6" chimney bracket
(welded at least - not pressed). Just silly......

For my untrained eye, could I tentatively ask what is wrong with the TV
aerial part? I can see that the radio aerial is wrong, but all I can
think
that's wrong with the TV aerial is that it's too close to the radio
aerial.

TIA :-)

Pity there's isn't a number 4, "after", picture!

TV aerial looks ok - certainly better than most!


I wonder what the metal paneling is doing to it's polar diagram, and I
don't fancy the impulses from the air conditioning motor directly
underneath it.

Well I think we have to assume that's the only place to put the aerial so
can't really avoid being close to the metal panelling. Yes it could be moved
away from the aircon unit but this is unlikely to cause any problems. Yes a
different type of aerial (and lighter) would have been better in this
"enclosed" location. Yes the person looking out of that window won't be
happy if they are into feng-shui. Yes galvanised brackets would have been
better, and tape rather than cable ties, and stop using those awful coach
bolts - but in general the TV aerial part of this installation is fine -
better than most. They've got the basics right - 1.5" mast - 2 piece bracket
with adequate spacing, they haven't fixed it into the top coarse of bricks
as is normally the case, they've clipped the cables etc etc.

Yes, I quite agree that you wouldn't really choose to use an FM aerial
for DAB but the ones without a balun really do work quite well and in
this case I took analyser readings with a true DAB dipole and with the
FM one and they were so close as to make no difference. As the main
pont of the call was to sort out the TV reception and it was my idea
to improve the radio, the "upgrade" from the silly use of the halo was
more than worthwhile.
It is quite true that the FM ones with a balun are completely useless
for DAB.

As far as the TV aerial was concerned, there was essentially nothing
wrong with the aerial. A decent Triax, solidly mounted. It was just
that it was almost fully enclosed by the building and was facing
slightly into it. Fortunately it was not actually facing the right way
and faced away from the building when it was directed properly. I
would not have chosen to fit it so close to the metal cladding and
certainly not so close to the airconditioning units but apparently
they were fitted after the aerial.

The main problem with the TV reception was a mixture of tetra and
other local radio transmission which was cured with a mixture of tetra
filter, band filter and attenuators. I studied the analyser carefully
as the air conditioners cut in and out and there was no noticable
affect.

There is another "halo" aerial mounted in the same way (vertically),
on a bungalow about a mile from this one. It appeared about two years
ago as part of a complete new TV and radio erection on the chimney.
And then there is the "high gain" new TV aerial that has been added
under the existing aerial on the mast on the house almost opposite
mine, which is vertically polarised. Our transmitter is horizontally
polarised and so is every aerial in sight so heaven knows why the
installer thought it was right. I assume it came with the clamp
mounted that way and he didnt like to change it!

In article
,
wrote:
Vertical FM dipoles without a balun work so well on DAB it's not
always obvious which feed is which is you've fitted a DAB dipole as
well. But FM dipoles with baluns are crap for DAB.

I have a 4 element FM aerial with balun which was also feeding a DAB tuner.

Thinking it would be theoretically better vertical for both, swung it -
and got worse results on both. ;-) The DAB becoming unusable.

--
*Never miss a good chance to shut up.*

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

In message
,
widgitt writes


I studied the analyser carefully
as the air conditioners cut in and out and there was no noticable
affect.

I would have thought that air conditioner units would use induction
motors (or similar). If so, they shouldn't cause any interference.
--
Ian

they haven't fixed it into the top coarse of bricks
as is normally the case,

Yes, as I said, I have no real problem with the TV aerial apart from
it facing into the building.

Actually you mention the top course of bricks......if you look closely
at the middle picture you can see where the installer tried that first
and decided it was a bad idea. The bolt is still there.

....snip...

I noddy question but assuming the radio transmitted is in the same direction
as the Tv transmitter, presumably there would be no problem with mounting
the halo vertically. The problem would be that you would get nothing
off-axis.

Paul DS,