169 replies to this topic

[geesey]

Here's the thing.
I can view all channels perfectly from 6am to 7am most days.
Then after 7am Ch 10 (digital 36) starts breaking up, followed by SBS digital 37) and Ch 7 (digital 3 progressively throughout the day. Ch 10 is always the worst for most of the day.
I have tried to get comments from other Townsville viewers on the DTV forum but haven't had much luck so far.
I am not so sure now that it is an equipment problem. More like some interference coming into play.

[steveinqld]

steveinqld, on Jan 8 2007, 10:50 PM, said:

Heavy Rain? Hah, that's not something we've had to worry about here for about a year!

Would you believe it?
I got home early from work to install a new UHF antenna, only to notice a storm coming.
35mm of rain and 15 minutes later I can confirm that when it rains I get NO digital channels.
8:30pm now, everything still wet, still no channels, still lightning around and my UHF antenna is still on the ground!

At least there will be some happy farmers around.

Steve

[wahroonga farm]

geesey, on Jan 9 2007, 09:42 AM, said:

Here's the thing.
I can view all channels perfectly from 6am to 7am most days.
Then after 7am Ch 10 (digital 36) starts breaking up, followed by SBS digital 37) and Ch 7 (digital 3 progressively throughout the day. Ch 10 is always the worst for most of the day.
I have tried to get comments from other Townsville viewers on the DTV forum but haven't had much luck so far.
I am not so sure now that it is an equipment problem. More like some interference coming into play.

Like I said earlier something has changed (and it's certainly not the commercial provider).

Maybe the old antenna/connection/feeder/connectors has corrosion problems (Townsville's 'by the sea')-> increased interference.

Suspect it's time for a antenna/feed  upgrade.

[Tahoma]

geesey, on Jan 9 2007, 08:42 AM, said:

Here's the thing.
I can view all channels perfectly from 6am to 7am most days.
Then after 7am Ch 10 (digital 36) starts breaking up, followed by SBS digital 37) and Ch 7 (digital 3 progressively throughout the day. Ch 10 is always the worst for most of the day.
I have tried to get comments from other Townsville viewers on the DTV forum but haven't had much luck so far.
I am not so sure now that it is an equipment problem. More like some interference coming into play.

Hi geesey.

I live in Townsville (West End), let me know your suburb and I may be able to help you.

Regards,   Tahoma

[geesey]

Tahoma, on Jan 10 2007, 07:37 AM, said:

Hi geesey.

I live in Townsville (West End), let me know your suburb and I may be able to help you.

Regards,   Tahoma

Thanks Tahoma,
I live in Cranbrook with a direct line of sight to Mount Stuart.
I have had a look at the aerial and it is only 7 elements, is rusted in places and the cable attachment is suspect. I think I need to upgrade the coax cable as well as the antenna.
I only get decent reception on ABC and WIN. (I think the antenna isn't even made to tune digital channels 36,37 and 38 - Ten, SBS and Seven).

I have contacted Townsville Electronics  who replied

"You must have a problem somewhere as the reception in your area is usually very good.
There may be a fault on the antenna where the cable attaches. There may be a problem with moisture getting into the cable and causing corrosion.
You usually must have good reception on analogue to be able to get good reception on digital. Digital will only improve a ghosty signal. It will still have problems with a weak signal.
To be able to split the signal to go to two other rooms you will need three times the amount of signal that is required for on TV plus a bit more for cable and splitter losses.
I would say that you will need a new antenna and the coax cable replacing."

[Tahoma]

geesey, on Jan 10 2007, 08:04 AM, said:

Thanks Tahoma,
I live in Cranbrook with a direct line of sight to Mount Stuart.
I have had a look at the aerial and it is only 7 elements, is rusted in places and the cable attachment is suspect. I think I need to upgrade the coax cable as well as the antenna.
I only get decent reception on ABC and WIN. (I think the antenna isn't even made to tune digital channels 36,37 and 38 - Ten, SBS and Seven).

I have contacted Townsville Electronics  who replied

"You must have a problem somewhere as the reception in your area is usually very good.
There may be a fault on the antenna where the cable attaches. There may be a problem with moisture getting into the cable and causing corrosion.
You usually must have good reception on analogue to be able to get good reception on digital. Digital will only improve a ghosty signal. It will still have problems with a weak signal.
To be able to split the signal to go to two other rooms you will need three times the amount of signal that is required for on TV plus a bit more for cable and splitter losses.
I would say that you will need a new antenna and the coax cable replacing."

Hi geesey,

Sounds  like an antenna + coax cable upgrade might be the answer. The Townsville Electronics reply is correct, your location should have all signals booming in, but the antenna  and cable are the key to good reception. Townsville Electronics have a good reputation, I've had a number of repairs done by them.
I"m sure they do antenna installations.

Regards,   Tahoma.

[geesey]

Tahoma, on Jan 10 2007, 08:27 AM, said:

Hi geesey,

Sounds  like an antenna + coax cable upgrade might be the answer. The Townsville Electronics reply is correct, your location should have all signals booming in, but the antenna  and cable are the key to good reception. Townsville Electronics have a good reputation, I've had a number of repairs done by them.
I"m sure they do antenna installations.

Regards,   Tahoma.

Thanks Tahoma,
A few people have recommended Townsville Electronics, so Iwill go with them to supply and install.
Cheers

[alanh]

geesey,
If you are getting signals from Mt Stuart ask for a band 4+ antenna. This will give all digital channels with better signals and analog except for ABC and WIN. If you use Yarrawonga or Parlington then you want a high gain band 5 antenna with an attenuator if there is too much signal. This is because a single frequency network is on already for ABC digital and will be used for all other stations.

AlanH

[Tahoma]

alanh, on Jan 10 2007, 10:00 PM, said:

geesey,
If you are getting signals from Mt Stuart ask for a band 4+ antenna. This will give all digital channels with better signals and analog except for ABC and WIN. If you use Yarrawonga or Parlington then you want a high gain band 5 antenna with an attenuator if there is too much signal. This is because a single frequency network is on already for ABC digital and will be used for all other stations.

AlanH

geesey,

Your only choice is Mt.Stuart, Yarrawonga is directional (25 watts) and sends no signal towards your suburb.

Also Partington only has ABC digital (Ch.54,  50 watts directional) to date and is a low powered site to cover  a small area shadowed by Mt.Stuart.

I've also heard that the commercial broadcasters would perfer not to go digital from there. It was a poor choice
from the start (on top of a lighting tower in the railway yards).

A small correction alanh, it's analog ABC VHF 3  and SC Ten VHF 7 that a band 4 + antenna would not do well from Mt.Stuart.

Analog SBS (28) Seven Qld (34) and WIN (40) would be well received on a uhf band 4 + antenna, along with the digitals 31, 36,37,38,& 41

Regards.

Tahoma.

[geesey]

Tahoma, on Jan 11 2007, 04:57 PM, said:

geesey,

Your only choice is Mt.Stuart, Yarrawonga is directional (25 watts) and sends no signal towards your suburb.

Also Partington only has ABC digital (Ch.54,  50 watts directional) to date and is a low powered site to cover  a small area shadowed by Mt.Stuart.

I've also heard that the commercial broadcasters would perfer not to go digital from there. It was a poor choice
from the start (on top of a lighting tower in the railway yards).

A small correction alanh, it's analog ABC VHF 3  and SC Ten VHF 7 that a band 4 + antenna would not do well from Mt.Stuart.

Analog SBS (28) Seven Qld (34) and WIN (40) would be well received on a uhf band 4 + antenna, along with the digitals 31, 36,37,38,& 41

Regards.

Tahoma.

Thanks again,
Townsville Electronics are recommending a Antenna type Matchmaster DG27.

"01MM-DG27 Digital compatible UHF/VHF X Type Colinear Ch(6-12) (21-69)27 Element Antenna Best suited to metropolitan & regional areas to receive VHF Channels(6-12)(21-69)"

[wahroonga farm]

Should be a shoe in 4 your location.

http://www.matchmast..._DG27_specs.pdf

[alanh]

Wahroonga Farm,
I do not agree with you. My main objection is that the UHF section goes from channel 21-69. Townsville's main transmitters only need from channel 27-49 or less. Restricting the frequency range increases the sensitivity of the antenna to the channels specified. Also it less likely pick up UHF CB, two way radios and mobile phone base stations.

On my selection link for band 3 & 4+ there is no matchmaster, but there are other manufacturers.

AlanH

[wahroonga farm]

Hi Alan,

I agree from a purist point of view you need a Band 3, 4+ rather than a Band 3, 4+5, say a Hills SMX14B4+ or even a SMX24B4+ VHF (6-12), UHF (28-50),  .... but in reality in a prime reception location ...... the addition of Ch 51-69 .... ????

It's really a sad indictment of the local (expert) providers (who haven't automatically sourced the most appropriate antenna's).

[alanh]

Wahroonga Farm,
True but it atleast does not have band 1. Look around and see where band 1 is still being installed in digital installations. There is no regulation of the installation industry to see that the installers actually have to know anything technical.

AlanH

[geesey]

alanh, on Jan 10 2007, 10:00 PM, said:

geesey,
If you are getting signals from Mt Stuart ask for a band 4+ antenna. This will give all digital channels with better signals and analog except for ABC and WIN. If you use Yarrawonga or Parlington then you want a high gain band 5 antenna with an attenuator if there is too much signal. This is because a single frequency network is on already for ABC digital and will be used for all other stations.

AlanH

(Townsville, Qld - Mt Stuart).
Thanks Alan,
We have had some fairly overcast days as well as heavy rain on and off in the past week.
Surprisingly my reception is best when it is raining and I can view all digital channels perfectly.
I still think there is something going on between me and Mt Stuart that is interfering with my signal and I still say that the Channel 10 signal is very poor (compared to others) from their end (judging by some other comments to this post).
I will try to get a Band 4+ antenna installed. Will that still pick up the analogue channels?.
Installers here seem to recommend multi band antennas.

[Tahoma]

geesey, on Jan 21 2007, 02:03 PM, said:

(Townsville, Qld - Mt Stuart).
Thanks Alan,
We have had some fairly overcast days as well as heavy rain on and off in the past week.
Surprisingly my reception is best when it is raining and I can view all digital channels perfectly.
I still think there is something going on between me and Mt Stuart that is interfering with my signal and I still say that the Channel 10 signal is very poor (compared to others) from their end (judging by some other comments to this post).
I will try to get a Band 4+ antenna installed. Will that still pick up the analogue channels?.
Installers here seem to recommend multi band antennas.

Hi geesey,

A band 4 + UHF antenna covers channels 28 - 50 (approx) and a alanh  says a band selective antenna will have the highest gain. RG6 Quadshield coax is also a must, including fly leads.
Regarding the analog channels. SBS channel 28
                                              Seven Qld    34
                                              WIN            40
will also be covered, but not SC Ten VHF 7 or ABC VHF 3.
The digital channels from Mt Stuart are:-
ABC   UHF 31
SC Ten     36
SBS          37
Seven Qld 38
WIN          40

Also make sure you don't have a VCR or an Austar tuner in the system with it's  RF output anywhere near the above channels.
I receive Mt Stuart also any have not seen any problems with SC Ten.
A job I did yesterday had one of those older VCR's that had a small screw adjustment for it's RF out, tweeking this slightly I was able to obtain all analog channels cleanly, whereas previously Seven Qld. was unwatchable.
Good luck.

Tahoma.

[alanh]

Tachoma,
Thanks,
I normally assume that the VCR/Foxtell modulators are not used and AV inputs are used instead. I should check the channels to see if they are around channel 35-37 next time

AlanH

[Tahoma]

alanh, on Jan 22 2007, 10:27 AM, said:

Tachoma,
Thanks,
I normally assume that the VCR/Foxtell modulators are not used and AV inputs are used instead. I should check the channels to see if they are around channel 35-37 next time

AlanH

Hi alanh,

Just noticed my error, WIN digital from Mt Stuart is Channel 41.


Tahoma.

[geeorama]

Tahoma, on Jan 21 2007, 04:51 PM, said:

Hi geesey,

A band 4 + UHF antenna covers channels 28 - 50 (approx) and a alanh  says a band selective antenna will have the highest gain. RG6 Quadshield coax is also a must, including fly leads.
Regarding the analog channels. SBS channel 28
                                              Seven Qld    34
                                              WIN            40
will also be covered, but not SC Ten VHF 7 or ABC VHF 3.
The digital channels from Mt Stuart are:-
ABC   UHF 31
SC Ten     36
SBS          37
Seven Qld 38
WIN          40

Also make sure you don't have a VCR or an Austar tuner in the system with it's  RF output anywhere near the above channels.
I receive Mt Stuart also any have not seen any problems with SC Ten.
A job I did yesterday had one of those older VCR's that had a small screw adjustment for it's RF out, tweeking this slightly I was able to obtain all analog channels cleanly, whereas previously Seven Qld. was unwatchable.
Good luck.

Tahoma.

Sorry to be stuck on this but:
It is absolutely pouring rain at the moment and I am getting the best reception I have ever had on all digital channels including SC Ten digital from Mt Stuart.
I still need the analogue channels so I will have to get a multi band antenna not just BAND 4+.?
I don't have any Austar or VCR connected and tuning in the system, my DVD/VCR just simply feeds from my STB signal (the way it has always without problems until lately).

[wahroonga farm]

geeorama, on Jan 31 2007, 01:23 PM, said:

Sorry to be stuck on this but:
It is absolutely pouring rain at the moment and I am getting the best reception I have ever had on all digital channels including SC Ten digital from Mt Stuart.

Possibly interference that's cut out in the rain?? Maybe a stretch but cud be Analogue TV from Cairns?

Where r u?

geeorama, on Jan 31 2007, 01:23 PM, said:

I still need the analogue channels so I will have to get a multi band antenna not just BAND 4+.?

Yes gets a bit messy, so you'll need a Band 2, 3, Band 4+. Mt Stuart Channels

So if your current analogue reception is fine, I'd suggest that you purchase a new Band 4+ and diplex it with your existing antenna. This will take VHF (only) from the old antenna and UHF (only) from the new antenna.

Of course the old antenna may be the source of digital interference, so with two antennas, you could disconnect the old one (VHF component) to test this.

geeorama, on Jan 31 2007, 01:23 PM, said:

I don't have any Austar or VCR connected and tuning in the system, my DVD/VCR just simply feeds from my STB signal (the way it has always without problems until lately).

Worth disconnecting the VCR in any case to see if anything changes

[mtv]

Before deciding what is required to provide the best reception, first you must know what signal levels and quality are present at a given location.

The key to digital reception is obtaining signals of adequate power and quality At THE ANTENNA.

Amplifiers should only be used to compensate for distribution losses, not to try and increase signals which are too low/not present.

Over-use of amplifiers without prior knowledge of signal power and Bit Error Rates is almost guaranteed to not only amplify existing problems, but to also create new ones.

Selection of the correct antenna for a particular location, together with accurate digital measurements to locate the best mounting location for the antenna are things which make every installation unique.

A "blanket post" across every regional area DTV forum recommending such bad practice may be considered 'trolling'.

As you are a new member, having only joined the forum today, burnoutking2 perhaps you could share with us your location, what channels you are receiving and from where, and what antennas and amplifiers you are using to achieve this.

I have my suspicions this poster is closely related to recently suspended troll, tyrewarmer20/dodgy

[dajodan]

Alan,

I live in Hervey Bay, Qld. I am a bit lost with what is "poor signal" for digital tv.  We have an LG LCD 82cm TV with a built in HD set top box.  We still have an old analogue airiel on the roof which is pointed at Mt Goonanaman and our cabling from the antenna to our splitter is the original cabling.  Airiel and cabling are both about 10 years old. We also have a booster on the airiel which is the same age as the airiel.   We do have a lot of trees around the yard and we were told that these would cause reception problems.  We were also told that the airiel may need replacing.

My problem is this.  We can have perfect picture on each channel some days and other days it is crap.  Some days channel 9 and ABC are crap and channel 7 is perfect, then for some reason it will reverse and channel 7 is crap and channel 9 and ABC are perfect.  Then just to complicate things both 7 and ABC will be crap and channel 9 good.

We can have picture break up on some channels but at the same time other channels are perfect.  We have had days where there is absolutely no breeze (to blow the tree branches aound) and we still have crap picture.  We have days where it is blowing a gale and there is no picture break up at all.    

Why is there:

Picture break up on some channels but not all.  If the digital signal was being interrupted wouldn't the break up occur on all channels?

Such a vast range in signal quality.  I can be looking at the signal strength which is showing "good" then in the blink of an eye it has dropped to "bad" and no signal?

There just does not appear to be any consistency with the problems we are having.  We have considered changing the aerial but if it was the aeriel and/or cabling are causing the problem, wouldn't the problem be there all the time and not spasmodically as at present?

If you can offer any explanation as  why these problems are occurring and what the best remedies are it will be appreciated.  We are happy to change the airiel and cabling if it is necessary but it is the inconsistency of the problem/s that worries us about spening $300 or $400 and seeing nothing improve.  We are getting very frustrated with the whole concept of digital tv.

Edited by dajodan, 02 October 2007 - 10:02 PM.

[charlesc]

dajodan, on Oct 2 2007, 09:52 PM, said:

...I am a bit lost with what is "poor signal" for digital tv.
...We do have a lot of trees around the yard and we were told that these would cause reception problems.  We were also told that the airiel may need replacing.

First of all, thanks for the detailed brief of what your problems are .  That does help.  There are some docs in my signature below which may better help with explaining certain aspects of digital reception.

Quote

Why is there:  Picture break up on some channels but not all.  If the digital signal was being interrupted wouldn't the break up occur on all channels?

No, some channels are quite likely to be affected more than others, depending on reception problems (echoes, interference, cable/antenna losses) etc.

Quote

Such a vast range in signal quality.  I can be looking at the signal strength which is showing "good" then in the blink of an eye it has dropped to "bad" and no signal?

Measurements by TVs/STBs/PVRs are not very reliable.  They can be quite changeable, and are often not very reliable even as a guide.  A digital field strength meter would be more accurate in showing what is really going on.  This is particularly true if the signal is fairly poor and close to the 'digital cliff' (ref docs).

Quote

There just does not appear to be any consistency with the problems we are having.  We have considered changing the aerial but if it was the aeriel and/or cabling are causing the problem, wouldn't the problem be there all the time and not spasmodically as at present?

If your system is operating very close to the 'digital cliff', then your reception would be doing the sort of things you appear to be seeing.

To receive reliable digital reception you need to have sufficient margin in both signal strength and signal quality (ref docs).  Without that, you are likely to see problems.

As is often said, digital reception has three main states.  Perfect picture, no picture, or a picture that is breaking up (pixellating vision and popping sound).  The latter situation happens as you enter the digital cliff zone. What is needed is sufficient margin in reception to keep clear of that zone.

Edited by charlesc, 02 October 2007 - 11:01 PM.

[i hate tv]

dajodan, on Oct 2 2007, 09:52 PM, said:

Alan,

I live in Hervey Bay, Qld. I am a bit lost with what is "poor signal" for digital tv.  We have an LG LCD 82cm TV with a built in HD set top box.  We still have an old analogue airiel on the roof which is pointed at Mt Goonanaman and our cabling from the antenna to our splitter is the original cabling.  Airiel and cabling are both about 10 years old. We also have a booster on the airiel which is the same age as the airiel.   We do have a lot of trees around the yard and we were told that these would cause reception problems.  We were also told that the airiel may need replacing.

My problem is this.  We can have perfect picture on each channel some days and other days it is crap.  Some days channel 9 and ABC are crap and channel 7 is perfect, then for some reason it will reverse and channel 7 is crap and channel 9 and ABC are perfect.  Then just to complicate things both 7 and ABC will be crap and channel 9 good.

We can have picture break up on some channels but at the same time other channels are perfect.  We have had days where there is absolutely no breeze (to blow the tree branches aound) and we still have crap picture.  We have days where it is blowing a gale and there is no picture break up at all.    

Why is there:

Picture break up on some channels but not all.  If the digital signal was being interrupted wouldn't the break up occur on all channels?

Such a vast range in signal quality.  I can be looking at the signal strength which is showing "good" then in the blink of an eye it has dropped to "bad" and no signal?

There just does not appear to be any consistency with the problems we are having.  We have considered changing the aerial but if it was the aeriel and/or cabling are causing the problem, wouldn't the problem be there all the time and not spasmodically as at present?

If you can offer any explanation as  why these problems are occurring and what the best remedies are it will be appreciated.  We are happy to change the airiel and cabling if it is necessary but it is the inconsistency of the problem/s that worries us about spening $300 or $400 and seeing nothing improve.  We are getting very frustrated with the whole concept of digital tv.

Hi mate, I live in Bundy and recently had major issues with digital reception.

We went to Jaycar agent here in bundy and bought a new aerial and coax and just ripped the old stuff out (it still looked good).   Changed to quad shielded coax (15mtrs at about $1.15/mtr) and a 1MM-DG27 Digital compatible UHF/VHF X Type Colinear Ch(6-12) (21-69)27  aerial ($96), a few really good conectors and a few hours, Tv is now perfect.

Im pretty sure that this aerial would be great for you as we both source TV from the same hill, and roughly the same distance.

http://www.matchmaster.com.au/

[i hate tv]

Ps: When we replaced the whole lot, I also removed the masthead amp completely and receive all digital chanels perfectly.

Good connections, low loss cable and antenna are a must!  

You may not see it but a film of aluminium oxide from the salt air will create a massive barrier for your signal to penetrate.