IAN, I WROTE TO ANDY AT TETRA WATCH BECAUSE I'VE BEEN PUZZLING MYSELF
AS TO WHAT A TETRA MAST ACTUALLY LOOKS LIKE. HERE'S MY QUESTION TO
HIM FOLLOWED BY HIS RESPONSE.
hi there, can you give me some clarification on what Tetra
masts look like.
I recognise the ones like the one at Shoreham Airport, with the 3
spindles in a CND-like shape, with sticks like TV aerials.
But i'm confused about others. I have looked up onto the roof of the
Police Station itself but cannot work out which is the TETRA mast.
Also, I've seen loads of plain white poles, sometimes just one pole,
and sometimes 2 white poles opposite each other. These aren't Tetra
are they? (They often seem to be near railways i've noticed) But i
think you've got a pic of these in one of your pictures.
-------------
yes, it is confusing. There is no such thing really as a "tetra
antenna", there are only different styles that can be used by various
systems for better or worse performance.<br>
<br>
The plain white poles are used by Airwave in threes, but you will
also see pairs, typically used by T-Mobile (ref. your final
question). These are not to be mistaken with sticks on the top of
panels, which can just be lightning conductors!<br>
<br>
The folded dipoles (sets of four loops on sticks) are used more by
Airwave (certainly in threes) than other systems.<br>
<br>
"Panel" or boxed antennae actually have folded loops inside, and
there are TETRA examples (eg Felpham), but these are directional,
unlike the dipole loops and poles that radiate all around.<br>
<br>
We identify them by their frequency using directional aerials on
meters, but for the ground based ones the easiest way to tell is to
see if there is an Airwave identifier plate on the compound. On
rooftops, Sitefinder will (should) show the legally-placed ones.<br>
<br>
Hope that helps<br>
<br>
Andy<br>
Tetrawatch<br>
--- In
[hidden email], SArjuna@a... wrote:
>
>
> > Sue & Ian wrote:
> > Would the short tower next to the police station be a Tetra
mast? I have
> > heard reports that this is the new network used by UK police and
is
> > particularly bad on emissions.
> >
> > I live in Wisconsin, USA. I have never heard anything to
indicate
> that our police have a special system of their own. Perhaps it
is so bad just
> because it is short, which increases the power density people
nearby are
> exposed to.
> Yes, the Tetra system is truly horrible. Barry Trower sent
me a copy
> of his report on it, and you can also find his work on the Web.
> Regards,
> Shivani
>
>
>
>
> [Non-text portions of this message have been removed]
>
Locked
