'DAT45' type aerials springing up in Bedfordshire
Marky P
'triple boom Televes type' aerials. Not only are these aerials
unneccessary in this area, they are also badly installed. One example
shown a thin 1" mast, 2"x"2 bracket, mounted part the way down the
gable end when the top was perfectly accessable, and excess coax cable
wrapped around the mounting bracket. The cable snaked down the front
wall of the house (clipped, but baggy between the clips) and into the
house with a big glob of unsightly white sealant. The other house I
saw was basically the same but no extra cable wrapped around the
mounting bracket. I will try and get pics if I can.
Marky P.
Robby
A 1" mast should be ok, as long as the reflectors fall off in time ;)
matthew...@gmail.com
For all the (technically no doubt correct) sneering at the DAT 45s and
DAT 75s, you have to give credit to Televes for introducing the kind
of product that Mr 42 inch TV would like to see on his house to
"prove" he's got a good aerial. You look at it and it "looks"
expensive, it "looks" as if it might be technically superior, it
"looks" better than your neighbours 16 element Antiference standard
aerial.
Pub conversation:-
"I see you got one of those digital aerials put up"
"Yeah, it was a few quid more than the others but it looks great
doesn't it"
"Who did you use - I think I need a digital aerial"
"XY Cowboy Aerial Fitters did it - one other guy (writesaerials (sic)
i think) just wanted to sell me one of those bog standard aerials and
even tried to tell me there was no such thing as a digital aerial!
And he wanted to charge me the same amount! You've gotta watch those
cowboys don't you!"
"Yeah"
Matt
Ian Jackson
<b3a58c4d-89e8-49a1...@q11g2000yqh.googlegroups.com>,
matthew...@gmail.com writes
had no TV) put up a TV aerial 'just for show'.
--
Ian
Bill Wright
"Ian Jackson" <ianREMOVET...@g3ohx.demon.co.uk> wrote in message
news:NuGDYdCL...@g3ohx.demon.co.uk...
> I understand that, in the early days of television, some households (who
> had no TV) put up a TV aerial 'just for show'.
Yes, my dad says they used to order the aerial, saying, "We want to get it
before the rush starts."
Bill
J G Miller
> I understand that, in the early days of television, some households
Rather like respectable middle class households who engaged the services
of a telephone sanitizing company.
JohnW
> On my travels around Bedford recently, I've noticed an influx of
> 'triple boom Televes type' aerials.
They've also reached St Neots. There is one near the station that must
be line of sight with Sandy Heath.
John
J G Miller
> On my travels around Bedford recently, I've noticed an influx of 'triple
> boom Televes type' aerials.
Are they genuine Televes DAT-45 with the black plastic support piece in
the approximate centre, or are they the copycat Nikkai Tri-Fold 43-Element
antenna with the black plastic support piece at the tip?
Bill Wright
"J G Miller" <mil...@yoyo.ORG> wrote in message news:123749...@vo.lu...
Ohhh, that's cheeky!
Bill
Robby
The model before the DAT 45 was called pro 45, apart from the dipole that
is identical to it. Televes used to be popular round here, but with the
reflectors falling off not so now. Popular choice amongst riggers now
seems to the Vision 32 & 48.
Dave Plowman (News)
Marky P <mark.p...@talktalk.net> wrote:
> On my travels around Bedford recently, I've noticed an influx of
> 'triple boom Televes type' aerials. Not only are these aerials
> unneccessary in this area, they are also badly installed.
Same round here - and you can almost touch the CP mast. ;-) I can only
assume they are sold as some type of status symbol, as the cheapest
contract ones are usually ok. They same their money on the FM one, though,
just a halo.
--
*The modem is the message *
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
tony sayer
<insertmybu...@f2s.com> scribeth thus
And some might think a Sky dish is ugly;!...
--
Tony Sayer
Doctor D
> sight to the local Ogbourne St. George relay.
>
> Presumably the offending antenna-bodger 'needed' the extra gain of the
> DAT75 to offset the loss he'd managed to engineer by installing the
> stupid thing horizontally-polarised.
> --
> Tanuki.
Are you sure it wasn't looking past the relay to a distant HP DTTV signal?
In saying that, I keep meaning to photograph a DAT45 within 1 mile and with
perfect LOS to the 1kw Brecon relay station.
Doctor D
"J G Miller" <mil...@yoyo.ORG> wrote in message news:123749...@vo.lu...
Labgear also market one http://tinyurl.com/cxfuyx which looks very similar
to that Nikkai one (dipole is different)
Lots springing up around here, although signal levels can be marginal and
sometimes a wideband (Lark Stoke & Ridge Hill) is required.
They look very odd when VP though!
Bill
<f6bbb1c6-ab38-44c2...@y13g2000yqn.googlegroups.com>,
JohnW <johnand...@hotmail.co.uk> writes
Also one on the back of the sports centre beside Ernulf School. 6 miles
at most from Sandy.
--
Bill
widgitt
>
> They look very odd when VP though!
Does anyone know what it does to the response pattern when one of
these is VP?
Marky P
Wow! I'm just down the road in the tiny village of Duloe. I'll look
out for that one :-)
Marky P.
Marky P
wrote:
They are the latter. I knew they weren't proper DAT45's, hence the
term I used in my OP. :-)
Marky P.
chunkyoldcortina
> In <9n70s4tckn5jtre1h...@4ax.com>, Marky P
> <mark.p...@talktalk.net> said
> sight to the local Ogbourne St. George relay.
>
> Presumably the offending antenna-bodger 'needed' the extra gain of the
> DAT75 to offset the loss he'd managed to engineer by installing the
> stupid thing horizontally-polarised.
If you mount one in a VP manner, are you effectively pointing in three
different directions?! :)
J G Miller
> They are the latter. I knew they weren't proper DAT45's, hence the term
> I used in my OP. :-)
Yes I did notice you had made the distinction, and I was trying to get
confirmation of what I thought you had seen.
But what will no doubt remain a mystery is, if the householders were
charged for the price of a genuine DAT-45, rather than the cheaper
copied style model price.
Bill Wright
"J G Miller" <mil...@yoyo.ORG> wrote in message
news:1237825...@vo.lu...
The difference would be small beer compared to the total invoice.
Bill
Paul Ratcliffe
>> Presumably the offending antenna-bodger 'needed' the extra gain of the
>> DAT75 to offset the loss he'd managed to engineer by installing the
>> stupid thing horizontally-polarised.
>
> If you mount one in a VP manner, are you effectively pointing in three
> different directions?! :)
Presumably the same applies to HP except in the vertical direction.
What is the function of the two outer booms? Seems like F all to me.
Alan
<insertmybu...@f2s.com> wrote
small beer? Surely you mean Red Bull?
--
Alan
news2006 {at} amac {dot} f2s {dot} com
Bill Wright
"Alan" <junk_...@amac.f2s.com> wrote in message
news:6c8B1ECt...@amac.f2s.com...
>>
>
> small beer? Surely you mean Red Bull?
Yes, of course.
Bill
Bill Wright
"Paul Ratcliffe" <ab...@orac12.clara34.co56.uk78> wrote in message
news:slrngsfsqn...@news.pr.network...
In your customarily succinct way Mr Radcliffe I think you have expressed a
great truth.
Bill
Paul Ratcliffe
wrote:
>> Presumably the same applies to HP except in the vertical direction.
>> What is the function of the two outer booms? Seems like F all to me.
>
> In your customarily succinct way Mr Radcliffe I think you have expressed a
> great truth.
Be interesting to perform surgery on one of these beasts and compare
measurements taken before and after.
Bill Wright
"Paul Ratcliffe" <ab...@orac12.clara34.co56.uk78> wrote in message
I guess it would be possible to remove the two outer director chains then
adjust the matching to compensate, and achieve much the same gain as before.
Bill
Paul S
"Tanuki" <mailer...@canismajor.demon.co.uk> wrote in message
news:nxdHHCAU...@demon.co.uk...
> In <slrngsfsqn...@news.pr.network>, Paul Ratcliffe <abuse@orac12.
> clara34.co56.uk78> said
>>What is the function of the two outer booms? Seems like F all to me.
>
s'obvious innit - it's to catch the signal reflections from the ground and
clouds. Also if it's a bit breezy as it waggles back and forth (what with
such a big aerial on the undersized pole) either the top or bottom ones will
be pointing at the transmitter so no probs there!
--
Paul S
Bill Wright
"Paul S" <morespam@nothanks> wrote in message
news:s-idnf19xOb1g1fU...@pipex.net...
The justification will be that they increase the capture area.
Bill
Ian Jackson
<insertmybu...@f2s.com> writes
consists of four insulated approximately halfwave elements. At the
tail end, the active element is usually still only a halfwave folded
dipole. How much more effective are the X-shaped directors compared with
single elements?
--
Ian
Marky P
None whatsoever.
Marky P.
Marky P
I've found a DAT 75 in a small village in cambridgeshire that's
attached to the wall using a small 2"x2" bracket. It is currently
falling off. I will take a pic sometime, if it's still there.
Marky P.
J G Miller
> I've found a DAT 75 in a small village in cambridgeshire that's attached
> to the wall using a small 2"x2" bracket. It is currently falling off.
Is that not a danger to those passing by underneath?
Bill Wright
"Ian Jackson" <ianREMOVET...@g3ohx.demon.co.uk> wrote in message
news:nClJjBFO...@g3ohx.demon.co.uk...
I'd say that for the same boom length the difference is about 1dB. If you
accept the extra boom length of a big high gain aerial versus a normal 18
element it is about 1.5dB.
I've always said that a major problem with aerials that are basically a yagi
but with elements of a more complex shape than a simple straight rod, is
that they tend to have less polarisation discrimination and often they have
polar response diagrams that show large unwanted lobes. These factors can
result in a c/n ratio that is worse than that from a straight 18 element,
despite the signal level being perhaps 1.5dB better.
Bill
Ian Jackson
the polar diagram etc. If there's so little advantage with this
configuration, I'm surprised that so many aerials use it (in its many
variants). It's possibly simply a case of 'styling' (ie 'that's what the
customer expects').
--
Ian
Bill Wright
>>I've always said that a major problem with aerials that are basically a
>>yagi
>>but with elements of a more complex shape than a simple straight rod, is
>>that they tend to have less polarisation discrimination and often they
>>have
>>polar response diagrams that show large unwanted lobes. These factors can
>>result in a c/n ratio that is worse than that from a straight 18 element,
>>despite the signal level being perhaps 1.5dB better.
>>
> That's interesting about the gain, and an interesting observation about
> the polar diagram etc. If there's so little advantage with this
> configuration, I'm surprised that so many aerials use it (in its many
> variants). It's possibly simply a case of 'styling' (ie 'that's what the
> customer expects').
It's a fact that large multi-element aerials are very often used because
they impress the customer, and allow the installer to extend the price scale
upwards. It's all about establishing 'product difference'.
Of course there are occasions when 'every microvolt counts', but given that
most urban locations are quite noisy, masthead amplifier noise (and thus
aerial gain) are often not as significant as might at first be thought. All
too often the installer gains a couple of dB that should in theory greatly
reduce pixellation, only to find that it doesn't, much. There are occasions
when a really big high gain aerial is called for, but they are few and far
between.
In any case, I can only repeat what I've been saying since 1978, that two 18
element aerials stacked or bayed will normally beat a high gain aerial that
has the same weight and windage, as long as they are installed with skill. I
see that Vision have finally agreed with me -- see their new product range.
Look forward to the Antiference response in a few months. Eventually we will
be back to the aerial that had more gain than any other, the quad MBM88 from
J Beam.
At the start of DTT I wrote
http://www.wrightsaerials.tv/topics/stacking-aerials.html
I don't agree with all of it now, but it gives an idea of what I'm on about.
A very import -- nay crucial -- factor is the present trend to use wideband
aerials for everything. Wherever possible use a grouped aerial. The
difference is considerable.
Bill