Ariel question

[Mongo82]

Any idea what this could be for, its on a communal roof and was not here 2 months ago. At first I thought it might be some sort of taxi ariel, but there is no service here, there is what seems to be an LNB link, not sure what the box above is. Electric broadband has recently been installed here but doubt its anything to do with that? Or is it? And this backs on to a an activity hub so maybe its to do with them.? Cheers Mongo

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[NOYB]

Might be community radio. Where exactly is it?

[Mongo82]

Hi, there has not been an FM community RSL here on the dial in a long while or new stations. Geographically there are better locations to get a link setup. And the receiver is pointing away from the highest ariel site where most ariels are for radio. Could be wrong though.The hub at the back does belong to local
authorities so its my suspicion it could belong to them, but this is a private block. Intriguing though.

[Mongo82]

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A bit of a better picture here.

[NOYB]

Maybe no RSL's but it could be a permament community radio station that is not on air yet. The link would be pointing back to the studio, not another transmitter site, especially existing broadcast site which would be far to expensive for a community station to operate from. The antenna at the top pole would be transmitting FM signal. Not sure what the box near the top of the pole is.

If we knew where it was we could role CR in or out!

[teckniqs]

It's hard to tell and I can't really see it properly but it does appear to look like an end-fed dipole or co-linear type monopole antenna and I've only ever seen a straight aerial like that with SHF receive dish(es) below it used for FM Broadcast applications.

....But I'm no expert and for all I know it could link to a local taxi firm.

What is the building that the aerial is on used for?

Sometimes I Google a building's address and type "antenna" or "dish" followed by "PDF" and see what comes up like a planning application for the radio equipment and find out a lot more details.

[Mongo82]

It's hard to tell and I can't really see it properly but it does appear to look like an end-fed dipole or co-linear type monopole antenna and I've only ever seen a straight aerial like that with SHF receive dish(es) below it used for FM Broadcast applications.

....But I'm no expert and for all I know it could link to a local taxi firm.

What is the building that the aerial is on used for?

Sometimes I Google a building's address and type "antenna" or "dish" followed by "PDF" and see what comes up like a planning application for the radio equipment and find out a lot more details.

Cheers Teckniqs, tried your tip out, not found anything as yet, would a scanner pick it up or an frequency meter? Not that i can get that close as its about 100ft away.

[Albert H]

It could be an "Aid Call" system for elderly and infirm people. These use radio pendants to summon help.

By the way Ariel is a washing powder! You mean "Aerial"

[Mongo82]

Cheers Albert yes my spelling is atrocious but i can spell antenna. So heres a thought just assuming i had a clean rig and this is just out there imagination right now, but say the old pirate in me wanted to fire 25w for a couple of hours every now and then assuming good modulation with a good matching jpole, good swr mounted 100 ft away, and just a bit lower, would i intefere with it? All hyperthetical ofcourse.

[radionortheast]

I thought it was a cb aerial when I first saw it dosen't explain the lnb thought

i've seen those tv aerials on top of a transformer building or water pumping station I don't know, no doubt used by pylon men or some other service to communicate whats happening back to base.

[THE GOVERNOR]

I think it's an Aid Call system for the elderly, I know that this is one

Screenshot_20190715-223100_Maps.jpg

[Mongo82]

I think it's an Aid Call system for the elderly, I know that this is oneScreenshot_20190715-223100_Maps.jpg

That would make sense, and there is someone who in the block that fits the description and possible need for that to be used.
I certainly would not want to cause the person interference, hence questions about the hyperthetical set up I mentioned above.

If that was not possible perhaps some sort of directional aerial? Also another question, would a lead flat roof act in some way as a ground plane if directly below the antenna? as You can see in the pics there is a flat roof. If not possible i'll have to put these wild theoretical ideas to bed.

Cheers Mongo

[Mongo82]

Hi, could someone please give us an informed opinion, such as setting an antenna up on, low power say 10 - 25 watts, about 80 - 100 ft away from the other antenna on the building. (I calculated the distance in leg strides which was about 42 so its roughly that far from the link fm dipole that is in the pics above. The calculation for a jpole which is just lets say 2m, and a support pole to give it another 2m. above the flat part of the roof (pic above) But think it would still be below the other antennas and perhaps just slightly over the apex of the roof.

I do like to set things up right. But if there is a slight chance of causing problems or overpowering the free-view TV or worst the link receiver (Possibly) aid system. Then I will have to forget the possible thought on this location. In the past there has never been things close such as amplification/ above aerials to interfere with, so is new territory. Its just an idea right now, but am sure some old heads will agree, once you have the radio bug, and an idea is in ya head its hard to shake off.

The Jpole as I understand radiates more to the horizon which is great but is still omni directional? and its simple and not as obvious as a dipole, so had set my mind on that. I had looked at the 7/8 for its its least conspicuousness but it would be flapping in the wind too much i think and difficult to tie it down. I also looked into the Hb9cv because of its directional attributes, looks easy enough to build, but looks like it could be a bugger to match properly and would stand out a mile and the size more awkward. Open to honest opinion good or bad.

Cheers Mongo.

[Albert H]

Mongo - Unfortunately, that's not a site that I'd ever consider using. Even if you didn't interfere with anything, if you were raided, the OFCOM idiots would always claim that there was interference, and that they were "acting on a complaint". Never give them a chance to make that claim!

Your transmitter could be entirely "clean" and you could still cause problems to nearby receivers, just by way of simple field strength - some poorly designed receivers simply freak out in proximity to even a couple of Watts! You can be sure that if that thing is an "Aid-Call" receiver, it will have the cheapest, shittiest, unscreened and unfiltered receiver that you've ever seen. They even house them in totally unscreened plastic waterproof boxes! They're made "down to a price" and their performance reflects that!

[Mongo82]

Thanks Albert, I sort of got the feeling that might be the case. And hearing Rf getting back into tge audio chain is a dead giveaway. 20 years ago i'd probably have chanced it but what you have said makes sense. Backburner for now it goes.

[LondonPirate]

Hi Mongo,
apologies for digging up a month-old thread but is this by any chance near a fire station? Looks quite similar to the pager alert system for retained firefighters.

[DoctorRadio]

Ive just been approached by a company to have something very similar on my roof; but theirs is for relaying smart meter and other low power stuff into the internet. The guy who tried to sell it didnt seem to know enough about what it was, and as we were hit by lightning some years ago we declinded the opportunity. (£40 a month rental for us hosting it though, so it must be worth their while.)

[Mongo82]

Hi Mongo,
apologies for digging up a month-old thread but is this by any chance near a fire station? Looks quite similar to the pager alert system for retained firefighters.

Hi, no not a firestation in the direction the LNB is pointing in, and quite a way from the nearest one.

Best Mongo