Do I need a new aerial?

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littleheaven

2120 posts

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#169659 22-Mar-2015 12:24

I'm on a crusade to get rid of Sky (just waiting for the Cricket World Cup to finish) and have bought myself the top-end Panasonic PVR to replace the MySky recorder, as all the shows I record are on the free channels anyway. I've discovered, however, that my Freeview reception is less than stellar. It seemed fine when I flicked through the channels on the telly (which has a Freeview tuner built in) but if I'd watched long enough I would have noticed intermittent pixelation, and over the last week channels 3 and 4 have dropped out completely. I can get improvement if I move the coaxial cable behind the TV unit around, but only at the expense of channels 1 and 2. There's no apparent sweet spot that works for all. I tried isolating sources of interference like power and speaker cables from the aerial cable, but that was actually worse.

I'm wondering if my signal is just not strong enough. On the PVR it shows the strength ranging from about 6-8 out of 10, but quality is sometimes 3-4 or less. The Freeview coverage map has me as "should be fine with high aerial" as I'm in a bit of a gully. The UHF one I have is the one that looks like an arrow, and was installed 19 years ago when we first got Sky (pre-satellite days) and that worked fine then, and later we got a dish and never worried about the UHF signal anyway. I'm the highest house in the street and the roof is 3 stories off the ground, but I don't quite have line of sight to the Sky Tower (I'm in Glenfield/Bayview area).

I've got a guy coming around after Easter to run some Cat6 cable under my floor so I can wire a network switch behind the TV unit, so I can get him to sort out the reception issues, but I'm curious to know what is likely to be required and how much it could potentially cost.

Geek girl. Freelance copywriter and editor at Unmistakable.co.nz.

richms

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#1264947 22-Mar-2015 13:08

If they have to go on the roof and they are a legit installer, it will be heaps.

Are you sure you dont have an amplifier on the antenna that you have discarded the power supply for? Often sky were taking them away when they did the UHF to Sat swaps as they were totally disconnecting the RF feed from the TV at the same time.

Unpowered amps will usually let enough signal thru to lock and sometimes work.

Richard rich.ms

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B1GGLZ

1961 posts

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#1265035 22-Mar-2015 14:26

Well if you have a 19 yr old sky UHF antenna it will be horizontally polarised and Sky Tower is Vertical so the very old antenna combine with wrong polarisation means you're fighting a losing battle to start with. In your area I'd suggest a new antenna and cabling and point it at Waiatarua. If Sky Tower is a better signal in your area then I'd say you still need a new antenna and cabling pointing at Sky Tower with the correct polarisation. Depending on your location there's also the infill Transmitter at Pinehill (horizontal) which may be better.

Edit. Perhaps you could post a picture of your antenna?

richms

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#1265039 22-Mar-2015 14:44

Its probably aiming at remuera if vertical, and at that distance would have had an amplifier for sure.

Richard rich.ms

littleheaven

2120 posts

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#1265058 22-Mar-2015 14:54

I don't recall having an amplifier - but it has been many years so it's possible I've forgotten about it now. When you say heaps, do you mean several hundred dollars? I don't mind shelling out a bit of money in order to make the accumulated savings of not paying $900 a year for Sky.

I did suspect the aerial is not really fit for purpose, as you suggest Bigglz. Here is a photo of it. It's pointing in the same direction (more or less) as others in the street of that design.

Edit: According to the compass in my phone, it's pointing approx 30 degrees NE (from Bayview).

Geek girl. Freelance copywriter and editor at Unmistakable.co.nz.

richms

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#1265061 22-Mar-2015 15:03

Well since its pointing the same way as the old VHF then it will be waitatrua that its going to, as nowhere else had VHF around the city really.
The box could be an amplifier, or just a passive diplexer.

Either case, it can come out. If you are confident getting up there then have a look inside it, at that age it probably is not F connectors so bypassing is harder than just buying a joiner.

Richard rich.ms

littleheaven

2120 posts

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#1265078 22-Mar-2015 15:21

richms: Well since its pointing the same way as the old VHF then it will be waitatrua that its going to, as nowhere else had VHF around the city really.
The box could be an amplifier, or just a passive diplexer.

Either case, it can come out. If you are confident getting up there then have a look inside it, at that age it probably is not F connectors so bypassing is harder than just buying a joiner.

Thanks - it's definitely in line with Waiatarua (non-arrow end pointing SE towards there), according to the Freeview coverage maps. I am totally not capable of getting on the roof, so I will leave it to the guy I have coming over in a fortnight to get up there and check the signal. Guess I'll just have to brace myself for the cost of some new cabling and maybe a new antenna.

Appreciate the advice.

Geek girl. Freelance copywriter and editor at Unmistakable.co.nz.

B1GGLZ

1961 posts

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#1265366 22-Mar-2015 21:56

littleheaven: I don't recall having an amplifier - but it has been many years so it's possible I've forgotten about it now. When you say heaps, do you mean several hundred dollars? I don't mind shelling out a bit of money in order to make the accumulated savings of not paying $900 a year for Sky.

I did suspect the aerial is not really fit for purpose, as you suggest Bigglz. Here is a photo of it. It's pointing in the same direction (more or less) as others in the street of that design.

Edit: According to the compass in my phone, it's pointing approx 30 degrees NE (from Bayview).

The antenna in the photo appears to be in good condition but the VHF antenna and diplexer are probably causing your low quality readings. Removing the VHF and diplexer and running co-ax direct to the UHF may help considerably. And a new phased array may help even more.

littleheaven

2120 posts

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#1265382 22-Mar-2015 23:55

B1GGLZ:The antenna in the photo appears to be in good condition but the VHF antenna and diplexer are probably causing your low quality readings. Removing the VHF and diplexer and running co-ax direct to the UHF may help considerably. And a new phased array may help even more.

Thanks for your advice. Some of the neighbours in the street who are further down the hill than me have the phased array kind, so I am assuming if theirs works okay, it should for me too. Hopefully whipping off the old rig and replacing it with a new one with nice new cables will result in much better reception. Prime and Choice TV come through great at the moment (strength and quality around 9/10) so I'm quite hopeful of greeting the others to match. For a while I panicked that I'd wasted my money on the Freeview recorder. When I arrange a time for the tech to come over I'll make sure to ask if he can come prepared to switch the antenna for me.

Geek girl. Freelance copywriter and editor at Unmistakable.co.nz.

Apsattv

2364 posts

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#1265384 23-Mar-2015 05:26

What are the actual frequencys that you are getting? this will confirm the site that you are getting signal from?

The UHF antenna is probably ok. But you can remove the diplexor and the VHF antenna and hopefully you have enough cable to pull up the main coax and connect directly to the UHF antenna. That should gain back enough signal to make it reliable.

Failing that get someone to come in and remove both antennas and do a full new cable run.

SATTV

1626 posts

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#1265424 23-Mar-2015 08:01

I am 99% sure that your aerial is pointing to Waitarua.
Glenfield is a interesting spot to get TV coverage, even in the old days we had some fun from time to time.

Rather than muck about, get yourself a reputable aerial installer, one who has a proper meter to survey your roof, install a few antenna, remove un-nessary components and possibley run new coax.

You are better off paying 200 - 300 to get it done properly, if you try yourself you could be up and down the ladder several times and maybe never resolve it.

Glenfield was one of the trial suburbs for the Telecom cable TV areas back in the mid 90's as there was such poor reception, there was also a trial area in Howick, I don't know why howick, possibly they could afford to pay more. The trail only lasted about six months and was gifted to another company, it never took off.

FYI to the others, there were two VHF transmitters off sky tower, TV3 and C4. TV3 was on channel 6 band III if I recall and C4 was Ch1 band I
I dont recall any analogue UHF TV up there.

John

I know enough to be dangerous

littleheaven

2120 posts

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#1265512 23-Mar-2015 09:53

I'm getting the following frequencies: 538 (TV1, TV2 - signal quality/strength out of 10 is 5/9), 570 (TV3, TV4 - 1/9), 602 (Maori, Prime, Choice 7/7) and 586 (Al Jazeera, TVSN, etc 4/6). So as you can see, reasonable strength on all but the quality of some is dreadful.

Glenfield is really hilly, and I'm halfway down a hill near Kaipatiki Creek, so blocked on one side by the ridge that Upper Harbour Drive runs along and on another by the one Glenfield Road runs along, but quite clear to the SouthWest so Waiatarua seems logical.

I can live with $300 to get it sorted properly. I'm a tiny little woman with a huge fear of heights so I'll leave it to the pros :o)

Thanks for all the responses.

Geek girl. Freelance copywriter and editor at Unmistakable.co.nz.

littleheaven

2120 posts

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#1279210 8-Apr-2015 19:19

Thanks to everyone who helped out with this topic - I had a tech over today and it was indeed the cabling and diplexer causing the issue. I was getting great signal through the antenna but terrible through the wall connection behind the telly. He removed the diplexer and old VHF antenna, trimmed the coaxial cable back to where it was sound and re-connected the UHF antenna. Now I have perfect signal strength and quality on all frequencies. Calling Sky tomorrow to cancel my subscription!

Geek girl. Freelance copywriter and editor at Unmistakable.co.nz.