638 replies to this topic

[mtv]

As mentioned, pics of the antennas, amps etc would be helpful.

Specs on the amps used and type of cabling too please.

Antenna type and mounting position is critical in difficult reception areas.

You MUST start with sufficient signal quality at the antenna, otherwise amplifying the signals won't help.

It would be good if we knew the installer's definition of 'OK' was in regard to your signals, as accurate signal measurements are needed to assist determining what's happening.  Eg: DCP, BER, MER, NM etc.

[gpaulid]

Hi, just need some advise.

I live in Kirrawee, Sydney (near the Royal National Park) - we have half down a valley in the area. We finished a complete renovation this time last year. Installed a new aerial (Matchmaster 01MM-DC21A). The installer also installed a amplifier in the roof cavity to booster the signal. We tend to experience bad reception on Channel 10 (as associated channels) as well as SBS (and associated channels).

Channel 7 is the strongest and ABC is good as well. Channel 10/SBS deteriorate when the weather is windy, cloudy or its raining - it may be okay on a good sunny day. Our TV is a Panasonic 55VT30A and it has a signal strength and signal quality reading in one of the menus. For SBS is shows a good signal strength and mostly poor signal quality. One would think that it should be the case but maybe this in-built meter is not very accurate.

I plan on getting the installer back but I am trying to understand what to look for? Is it a case of simply adjusting the position/direction of the aerial to improve reception for the bad channels. The previous aerial on the housse was twice the height - previous owners.

I seem to re-call reading somewhere that a amplifier can cause more problems with a signal? is that true. Any advise is appreciated. Thanks in advance.

George

[nbound]

If the problems have occured since the new system was installed its likely that you will either need to move the antenna to a better position, get a more powerful antenna, or get good separate antennas for VHF and UHF.

An amplifier is only good for boosting weak clean signals. So if the signal wasnt up to scratch by the time it hits the antenna, you are gonna get problems. It is likely the booster will need to be retained.



Of course nothing beats an installer with a meter which can tell you exactly why a problem is occuring.

[alanh]

George,
The installer should be able to accurately measure signal strength at all outlets and the Bit Error Ratio. The BER can indicate the presence of reflected signals which in analog appear as ghosts.

Do not spend a lot on UHF reception because SBS will move to channel 7 when analog channel 7 is switched off at the end of next year. TSN is also likely to be band 3 as well.

A Matchmaster 03-DR3010 is more sensitive and more directional than your new antenna for all channels except for the current SBS and TSN. If you have blocking terrain between you and Artarmon then a 03-Bigray may be required.

Put your address into www.digitalready.gov.au

nbound
"Of course nothing beats an installer with a meter which can tell you exactly why a problem is occuring " he is already paying an installer who has a meter.

Your generic answers are of little use as he has done what you recommend already and it has not worked.

AlanH

[nbound]

 alanh, on 10 December 2012 - 11:30 PM, said:

nbound
"Of course nothing beats an installer with a meter which can tell you exactly why a problem is occuring " he is already paying an installer who has a meter.

The reason why that sentence was put in was to tell him we dont exactly know the issue, but the installer should be able to tell him when he arrives. He hasnt actually tried what I suggested the technician would do, unless it was tried on a previous page or thread.

 alanh, on 10 December 2012 - 11:30 PM, said:

Your generic answers are of little use as he has done what you recommend already and it has not worked.

AlanH

And yet, you basically give the same advice (better antenna/location). Good one alanh!

Neither are my answers different from the generic answers you, or others give, as that is all anyone can give without the full information provided by a meter. Of course Ive stated similar to you before.

 alanh, on 10 December 2012 - 11:30 PM, said:

George,
The installer should be able to accurately measure signal strength at all outlets and the Bit Error Ratio. The BER can indicate the presence of reflected signals which in analog appear as ghosts.

Do not spend a lot on UHF reception because SBS will move to channel 7 when analog channel 7 is switched off at the end of next year. TSN is also likely to be band 3 as well.

A Matchmaster 03-DR3010 is more sensitive and more directional than your new antenna for all channels except for the current SBS and TSN. If you have blocking terrain between you and Artarmon then a 03-Bigray may be required.

Put your address into www.digitalready.gov.au

Finally, you push the band 3 antenna line once again (though you have finally appeared to have at least softened your stance - great! ).

George, most installers would recommend you continue using an antenna system capable of receiving all stations (incl SBS/TVS), unless you are certain you can go without for a whole year. A Band 3/4 antenna will continue to work if even if both SBS and TVS move to VHF.

Besides, the future channel allocation of TVS is currently unknown, while moving from UHF to VHF is a good possibility at some point after SBS's move it is not certain. Keep that in mind if you wish to retain the communtiy station in the mean time and into the future.

Please note, despite alanh's matter-of-factly posting style and high post count he is not an installer, and infact often quarrels with other installers here.

Edited by nbound, 11 December 2012 - 02:56 PM.

[debruis]

Hi George,

  When the installer returns ask him if he is getting reading of 50dbuv+ signal strength and 28-31db signal to noise ratio on each channels from the antenna. He may have to relocate or change antennas as suggested in other posts. If he has installed a mast head amplifier then ask him to replace it with a distribution amplifier as this will not affect the incoming signal as it will only compensate for splitter and cable losses. I have had success with this installation method in fringe signal areas.

[nbound]

Most distribution amps have worse noise figures than masthead amplifiers, it is likely to compound any noise related problems. Unless you meant the other way round? .

Edited by nbound, 11 December 2012 - 08:45 PM.

[mtv]

Self-noise level varies with amp design, so there's low-noise variants of both masthead and distribution amps.

Kingray have some excellent low-noise distribution amps which don't have high output levels (typically around 18dB) which I've found to offer good performance.

Naturally, as with all amps, they should only be used to compensate for distribution losses, not in an attempt to improve poor signal quality, the latter can only be improved successfully by installing the right antenna for the individual location and mounting it where there is good signal quality 'at the antenna'.

This can only be determined with a signal site survey..... testing different antennas at diferent locations and at different heights, using a digital meter/spectrum analyser... in the hands of a skilled operator.

I am very familiar with the Kirrawee area.

Most parts have excellent digital reception, providiing you don't have a blocked signal path from buildings, terrain, etc. (which it sounds like you do) so it's essential a full signal site survey is performed to determine the best combination of antenna type and mounting position.

Some parts of Kirrawee can receive the Kings Cross UHF translators.

From experience, I would not expect a Matchmaster 01MM-DC21A antenna to perform well in poor signal quality situations, however, as mentioned above, various antennas should be tested and the most effective one selected.

The mounting location and height can be critical.

[nbound]

It was never a blanket statement, but for the most part is quite true... Taking your example, if you are refering to the MDA20 its technically a masthead/pre-amp with its single output port, and would certainly be very low noise (Kingray do market them as dist amps aswell due to their great performance.) . If you are refering to the SA164/R then its noise figure is higher than than any of the MHW series. As are either the higher gain DW32 and DW42 and the older models (SAM224 etc)

Edited by nbound, 12 December 2012 - 07:01 AM.

[alanh]

Nbound,
It is the customer who should decide whether they want UHF or not, not the installer. The installer should tell the customer the situation and let the customer decide after all they know if they watch SBS and TVN or not. After all they are paying for an antenna which is going to be used for more than 12 months.  This is especially true in poor signal areas. Band 3 only antennas work much better than combos and are generally cheaper for the same band 3 gain.

This also applies to most of Canberra as well. SBS will also be going to band 3 leaving no UHF except for translators.

This is a similar argument used against me when I started recommending the use of band 3/4 antennals with no channel 2 elements years ago. The customer may wish to watch analog. Only ABC analog was affected.

As far as Kingray MDA20s go, only the MDA20H should be recommended except where UHF only is required. MDA20L covers analog channels 0 - 5A as well.

AlanH

Edited by alanh, 12 December 2012 - 08:00 PM.

[nbound]

 alanh, on 12 December 2012 - 07:58 PM, said:

Nbound,
It is the customer who should decide whether they want UHF or not, not the installer. The installer should tell the customer the situation and let the customer decide after all they know if they watch SBS and TVN or not.

I suggest you re-read my post:

 nbound, on 11 December 2012 - 06:37 AM, said:

George, most installers would recommend you continue using an antenna system capable of receiving all stations (incl SBS/TVS), unless you are certain you can go without for a whole year. A Band 3/4 antenna will continue to work if even if both SBS and TVS move to VHF.

That 2nd punctuation mark is a comma, not a full stop.

 alanh, on 12 December 2012 - 07:58 PM, said:

This also applies to most of Canberra as well. SBS will also be going to band 3 leaving no UHF except for translators.

Canberra has got nothing to do with this discussion. I already know the restack plans for Canberra.

 alanh, on 12 December 2012 - 07:58 PM, said:

This is a similar argument used against me when I started recommending the use of band 3/4 antennals with no channel 2 elements years ago. The customer may wish to watch analog. Only ABC analog was affected.

But of course in the real world, MATV systems with numerous analog sets (large residential complexes, some pubs/clubs), needed to be able to receive ABC analog. And if a person does not wish to upgrade their analog sets just yet, but wants good ABC reception, they have little other choice than a VHF-Low capable antenna.
These clients requiring such antennas have dwindled now (but not yet disappeared), but they dont really compare to this topic, as ABC digital was always available with the Band 3/4 antenna, and upgrading to digital could be put down as future proofing.

 alanh, on 12 December 2012 - 07:58 PM, said:

As far as Kingray MDA20s go, only the MDA20H should be recommended except where UHF only is required. MDA20L covers analog channels 0 - 5A as well.

The specs of all 3 MDA20 subtypes are on the packaging, and in trade catalogues, and again have little to do with the topic at hand.

Edited by nbound, 12 December 2012 - 09:02 PM.

[GoForMoe]

 alanh, on 12 December 2012 - 07:58 PM, said:

It is the customer who should decide whether they want UHF or not, not the installer. The installer should tell the customer the situation and let the customer decide after all they know if they watch SBS and TVN or not. After all they are paying for an antenna which is going to be used for more than 12 months.  This is especially true in poor signal areas. Band 3 only antennas work much better than combos and are generally cheaper for the same band 3 gain.

I'd strongly suggest that someone making a post saying that they can't get SBS and Ten wouldn't want to upgrade to an antenna for any cost that would only fix one of those problems. If the site test resulted in a situation where a VHF only antenna could fix the issues with Ten and a combination one couldn't, then perhaps there's a justification for the installer making a suggestion like that, but otherwise the cost difference is negligible and the loss of channels (even if you don't frequently watch them) is certainly not a good tradeoff - especially when there's no certainty that the antenna installed will perform well on the VHF7 SBS service or a theoretical TSN VHF10 service.

I would hope any antenna installer's first priority is getting an adequate and stable signal on all channels, not a hope of a signal in a year's time.

[nbound]

 GoForMoe, on 12 December 2012 - 09:01 PM, said:

I'd strongly suggest that someone making a post saying that they can't get SBS and Ten wouldn't want to upgrade to an antenna for any cost that would only fix one of those problems

Teeheehee , I was actually going to point that out too, but unfortunately the usual alanh argument sidetracked me.

[alanh]

Nbound,
Canberra is relevant because this is where you are and the same argument applies. I don't care if you know the restack plans for Canberra, the point is that UHF will not be used for SBS, just like in Sydney. More than that those unique VHF vertical and UHF horizontal polarised antennas will not be required

What has channel 10 got to do with it? Wouldn't ABC digital be worse on channel 12.

What has MATV systems got to do with it? This thread is about a single antenna installation. The complaints before were for single houses and how the performance differences are not noticeable. Well removing all channels below channel 6 in the Penrith area had a big reduction in signal breakups.

Goformoe, The SBS7 signal will be received just as well as all the other band 3 stations even on an old antenna.

So Nbound do you tell the customer the options and let them decide?

AlanH

[nbound]

 alanh, on 14 December 2012 - 07:55 PM, said:

So Nbound do you tell the customer the options and let them decide?

I install for all channels unless asked otherwise (as that is what people expect).

In the very very very rare situation that getting SBS would cost a massive amount to receive compared to just VHF services, I have mentioned going without SBS as an option, all customers excluding one (well outside of Canberra) have opted either to do what was required, or I have refocused onto an alternative transmitter or alternate installation strategy to obtain all channels.

And even that customer was still able to get SBS via Austar on some TVs.

People dont like going without channels, no matter how little they watch them.

Edited by nbound, 14 December 2012 - 08:41 PM.

[GoForMoe]

 alanh, on 14 December 2012 - 07:55 PM, said:

Goformoe, The SBS7 signal will be received just as well as all the other band 3 stations even on an old antenna.

Read the post that was made initially -

Quote

We tend to experience bad reception on Channel 10 (as associated channels) as well as SBS (and associated channels).

As there are currently issues with the TEN11 signal, 'just as well' could mean just as badly. If all channels on band 3 were received just as well, the problem would be exclusive to SBS - the problems on Ten mean that there are issues with receiving particular channels in the particular location, not a broad issue with the UHF band, and the modern antenna and good reception of ABN12 means it isn't an issue of the antenna being unsuited to the upper end of the VHF band.

You can't guarantee reception of a channel not on air.

Quote

So Nbound do you tell the customer the options and let them decide?

The customer wants SBS fixed - the decision is already made for the installer.

I'll also point out that for one stockist I've been able to find so far with both in stock, you've again suggested a more expensive VHF only antenna over a VHF/UHF combination - so again, less channels and more cost - what customer would make that choice if offered to them?

[Tiny400]

Hi guys,
New to the forum and finding lots of very interesting info!
Thank you to everyone in the industry for being so helpful to the rest of us!

We have recently moved in to a house near Sutherland, it has an older antenna installed which has been bent by some fat cockatoos.....
The down cable is only twin shield cable, and I have cables the entire house in quad shield. There is approximately 11 outlets (every single room... And then some... Just in-case!) and we can only receive channel 9 (and its digital partners) reliably.
Abc is flaky, seven and ten are basically impossible.

Matchmaster website recommends an antenna and masthead amp, but I'm a little worried about amplifying a poor signal.

Could anyone in the area please suggest what may help, and/or suggest a local installer who could give us a quote to fix up the system please!

Thanks in advance,
Tiny.

[debruis]

Hi Tiny400,

   I have sent you a message with an estimate. You could also try these installers who are members CharlesC, MTV & StormAV as they work more on the south side of the Harbour Bridge.

[Storm AV]

Message sent.

Cheers debruis, the recommendation will always be returned mate.

[itguyaus]

I am in Beaumont Hills NSW and generally have good TV reception during the day using a Matchmaster with mast heas amplifier that has been working well for the past 12 years. From around the middle of last year onwards, often at night starting some time after 5:00pm and before 6:30pm  and often right up until 11:00pm or midnight, most digital channels immediately become unwatchable exept SBS, ABC, TVS and a few other minor channels.  Right up until this time when picture is clear the TV reports signal strength around 8.5/10 and Quality around 8.5/10.  At night I observe on Channel 9 and Channel 7, that the quality instantlys drops to around 1/10 when the interference period starts, but the signal strength remains at around 8.5/10.

The guy next door has exactly the same problem, and has had a TV guy come out several times, and has replaced his arial and mast head amp, moved his antanae. The installer doesnt come at night when the problem actually happens so he has never has really resolved the problem.

I'm thinking it must be some kind of local interference between where we are and the Sydney tv tower to mess with the quality of the signal so drastically and instantly.

On the dtv switchover site I see a new digital tower will be available at Kurrajong in Late January 2013 to service north west sydney.  I am keen to try it out. I got up on the roof today and rotated the antanae toward Kurrajong, but the only digital station I could receive was TVS, so I'm assuming the Kurrajong tower is not transmitting yet.

The information on the switchover site is confusing. In places it says December 2012, other places Jan 2013 and last week when I checked there was a mention of December 2013.
Does anyone know what date it will be turned on?

Thanks - Steve

[nbound]

New transmitters are notorious for being pushed back, Late Jan is still the latest I have heard, but dont be surprised if it doesnt happen until sometime in Feb. Sometimes, you may catch test transmissions before the official startup date.

[debruis]

Hi itguyaus,

  The reception where you are located should be fine. I have done installation out your way without call back for reception problems.  Reception quality is very dependant on antenna height and position on the roof. Some installations to get good reception the antenna is located just above the eaves. Also you may require seperate UHF and VHF antennas for good reception.  I generally do not need to use a masthead amplifier. If have also found with masthead amplifier that they can be tricky and sensitive to set up when amplifying VHF signals. If your antenna is as old as the masthead amplifier then I believe that is where the problem may lay. This is hard to diagnose without site survey and reading from a digital field strength meter.

[Storm AV]

Do you get the same problem every night or is it intermittent?

Do any of your nereby neighbours have a large cb antenna on their roof?

Chat with other neighbours if you can and see how far the issue is spread.

Best option get a experienced reputable installer to assess and correct the fault-Debruis would be the man!

[nbound]

Given the hours, Id lean more towards a fluorescent light, or some other evening only device.

[itguyaus]

Thanks guys,
My antannae is on a pole about 2 metres above the roof on the centre peak in the middle of my single story house with a few hundred metres clear line of sight before trees and hills.

It does not have to do with lighting at my house. I have tried turning off all lighting at the fuse box.
The problem does not happen every night, probably about 75% of the time though.

Most of the immediate neighbours i have asked so far have foxtel so are unaware of any issues. I may need to survey more to see where the problem ends.

Good point re Cb radio's I can't see any but may need to look wider around the area.

My next steps are:
1. Try the kurrajong tower when it is operational
2. Wait for my next door neighbours tv installer to solve the problem and learn from that (seems to be a lot of guesswork so far as the problem is never there during business hours when he has the measuring equipment out)
3. Get my own expert in to look at the problem, or start by replacing the antannae +amp with newer equipment.

Cheers, Steve