UHF reception issue

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Ultimate Geek
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#2043664 25-Jun-2018 16:50

Can you confirm you have your aerial correctly polarised? Mt Erin is vertically polarised meaning the elements should point up and down.

I've seen many clowns installing aerials on new builds facing Mt Erin mounted horizontally. In a high gain area they'll work OK but ultimately there will be some signal loss but in a low/poor gain area will mean there will be lots of signal loss. Every little bit helps.

Rikkitic

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#2043684 25-Jun-2018 17:24

At one point I had a photo on Geekzone but it has disappeared. Maybe they get deleted after a certain time. I will try to dig it out of the archives later. I don't have time right now.

The antenna is definitely correctly polarised. I made sure to check that at the time. It is vertical, not horizontal.

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Brunzy

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#2043701 25-Jun-2018 17:51

Fair point, but highly unlikely it would be the wrong polarity, you’d lose around 20dBuV which in a marginal area would leave you with nothing much usable.

nitrotech

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#2043717 25-Jun-2018 18:19

Having issues in Rotorua with DVB-T too, have put up new antenna, completely recabled - emailed freeview who said they don't deal with coverage issues - emailed JDA and no response.

All we pair shaped about 4-6 weeks ago before that had no issues for the previous several years

Apsattv

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#2043864 26-Jun-2018 06:43

Can you confirm you are using these frequencys?

all vertical
CH 29 k2
CH 33 mediaworks
CH 35 tvnz
CH 37 k1

A lot of the older style UHF fringe antennas out there are wide band covering channels 21 to to 69 which isn't needed these days and become a problem if there is 4G signals in the area.

Newer antennas are designed for the high end of the band being around channel 50 and filtered to prevent 4G interfearence. With the antenna designed more tuned for channels 26 to 50.

Since you are running 25M of cable the masthead amp may be worth a try. It goes as near to the balun as you can get it. Not 10 feet below the antenna.

Be sure to get a 4G filtered one.

Rikkitic

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#2043982 26-Jun-2018 10:39

Here is the antenna. I will check the frequency info later. The TV is in another room and isn't on during the day. The trees are not as much in the way as they appear in the photo, though they do partially obstruct LOS.

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Bung

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#2043985 26-Jun-2018 10:50

Seems to me that a lot of the height gained by the mast is lost by the aerial sagging forwards. I'd be working on next year's firewood ;-)

Rikkitic

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#2043988 26-Jun-2018 10:57

That's an illusion. It is pointing straight.

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Pumpedd

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#2043995 26-Jun-2018 11:15

As trees grow reception gets worse.

Bung

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#2043999 26-Jun-2018 11:21

Next thought, is the aerial still pointing as originally put up? I have enough trouble with the aerial twisting on the mast. That looks like the mast itself could twist where it is strapped to the flue.

Wiggum

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#2044000 26-Jun-2018 11:23

That antenna is sure to be shaky in even the slightest breeze. I don't see any Metal or cable stays in place. Perhaps you should think about adding some. Frankly I would be more concerned about that thing falling off and injuring somebody, opposed to freeview reception.

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Rikkitic

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#2044007 26-Jun-2018 11:39

No chance of it falling unless the house collapses. It is solider than it appears. It recently survived a gale force storm that did, for the first time ever, twist it around but did not damage anything. The correct orientation is marked and we put it back where it was. It was indeed the mast that spun and we have added something to prevent that. I have observed it in gale force winds and it hardly vibrates at all. I was impressed with the lack of movement. That is not an issue.

Now that I have posted images, I hope this thread is not going to become about what it looks like. My question is what I might be able to do to improve reception quality, which used to be perfect but has deteriorated for reasons I don't understand on the TVNZ mux only. I thought it might be related to frequency, but the mux is between others that do work fine. Would the transmission of that mux be weaker for any reason?

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Spyware

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#2044010 26-Jun-2018 11:45

All muxes are same power (too lazy to find out what exactly though).

To fix you would need a spectrum analyser and probably need to move antenna.

Rikkitic

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#2044014 26-Jun-2018 11:53

Thanks. That is useful to know.

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Wiggum

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#2044039 26-Jun-2018 12:39

Rikkitic:

My question is what I might be able to do to improve reception quality, which used to be perfect but has deteriorated for reasons I don't understand on the TVNZ mux only. I thought it might be related to frequency, but the mux is between others that do work fine. Would the transmission of that mux be weaker for any reason?

Install some metal or cable stays to keep it from moving. Even a 5mm movement in even the slightest breeze could have an effect on your signal quality. Especially if you are already on the fringe of reception. Making sure its properly aligned, and stays aligned is the first thing I would be concentrating on before doing anything else. Suprised you have created a new thread for this, because most of this has already been recommnded to you in your other thread.

Pixelation on TV NZ UHF

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