315 replies to this topic

[andrewlace]

Hi Alan,
1/10000 what somt of ber is that?

Next point, a ber of e03 will work provided the actual number of uncorrected errors coming through is basically non existant (this is the point where the picture breaks up).

read about cliff edge in relation to ber, go look it up and then post.

suggest that some instruments are more sensitive than others hence I have an ap01, which is of course more senstive on lower signals than the t40 I have.

Not to mention reed solomon uncorrected, these are the actual errors.  Furthermore there are pre and post viterbi ber.

alanh, on Feb 2 2005, 09:54 PM, said:

All,

Analog TV switchoffs are;
Mildura/Sunraysia between 1^st January - 30^th June 2010
The rest of regional Victoria between 1^st January - 30^th June 2011

Follow the sequence below to determine what you need to do. This applies to new and existing installations, in which pixellates (picture breaks up into blocks) and the sound chirps.

Antenna Selection

1. Determine the most appropriate transmitter site
Most regions have a main transmitter shown in bold and some translators. Translator is of lower power than the main transmitter for the region. Translators are used to fill in a shadow area caused by the local terrain. A translator converts the signal from one channel to another to prevent interference.
Click on Transmitter List to find you likely transmitter site(s)

Open on another screen
Coverage Area Maps and select the state and your DTV transmitter. If present this will give you a coverage area map to determine which site is best for you.

If an antenna technician can provide evidence that there are no signals at your site, you can get the ABC, SBS, two commercial stations and some radio channels directly from a satellite. Go to the end of this post.

2. Select the antenna type
From the spreadsheet use the antenna type to select the link below

H3
H4+
H5
H3Wb
V4
V4+
V5
H34

Caravans/Marine
Band 3, 4 - 5

Indoor Antennas

Antenna Type Drawings

“Antenna Replace”
Red background, white print.
Digital TV will never use channels 0 – 5A. This is due to the problem of impulse noise from electrical switching and arcing. You can minimise this problem if you antenna is not designed for these channels. Channel 0 – 5A antennas are very wide and are more liable to get bird and wind damage as well.

The best antenna is one designed for the TV channels to be received in your area. This is because all of the metal work will get used. This gives greater sensitivity to the channels you want and less to the unwanted ones.

“Antenna Replace”
Pale Blue background, red print.
A change in UHF band. Only replace antenna if the signals break up which may be weather dependent.

All analog channels within the antenna channel range will be receivable. This means that ABC1 analog is not received in Upper Murray, Orbost, Myrtleford, Central Victoria (Bendigo), Colac, Cobden, Murray Valley (Swan Hill), Nhill, Coleraine, NWarnambool and Western Victoria.

Cabling
It should be quad shielded RG6 with F connectors at any joins.
This is to minimise the pick up of electrical switching and TV signals other than picked up by the antenna.

Masthead amplifiers Should only be considered if the measured digital signals show there is too little signal. If that is not an option try the above techniques first.

Recognising interference
Better Television & Radio Reception
If you are within 6 km of the guyed lattice towers at Horsham. Please report his on this strand for further advice.

Please note this is general information. Use an antenna installer who can measure and error rates of digital signals (They should be able to give you Bit Error Rates (BER) figures of less than 1 in 10 000.) If they cannot do this, get someone else.

Apartments and retirement villages use Master Antenna TV systems (MATV)

Remember that analog transmitters will be switched off between Dec 2009 Metro, and 2013 in the last regional areas.

Australian Building Codes Board Digital TV Antenna Systems

These systems contain amplifiers for individual channels. In any non-digital installations you will generally find some digital channels are not receivable due to this filtering. Prior to upgrading or installing an MATV system make sure all receivers are digital or have a set top box. This will mean that the channel amplifiers can be retuned or replaced rather than installing another set of 5 amplifiers. Then specify that the installation must conform to Australian Standard 1367-2007. This will ensure that all digital channels will be available, including HD and surround sound when available.

Radio – FM, DAB and DRM
FM
None of the antennas listed above are designed to receive FM radio. The best way is to have an independent system Please read FM Antennas

DRM is another type of digital radio which will replace AM radio and will not use any of the above equipment.

More Information
How to get into Digital TV Pt 2 -What to do about the antenna "Silicon Chip" April 2008
For TV Antenna Basics +
For Radio Thread


If an antenna technician can prove no TV signals are available, then a free to air satellite receiver is an option.
Stations available


The programs are transmitted through the satellite in digital form, but in some towns are then retransmitted in analog. A home satellite receiver will receive the signal in digital, however there is none of the enhancements such as multi channel, wide screen etc.


To obtain reception read the following link
Out of area  reception

AlanH
Please post any queries in this geographic viewer's forum

[andrewlace]

Issues generally come down to the poor quality power supplies inside cheaper tvs, that said seldom have I seen a set that had that reception does not work.

The only set I've ever seen that bad was two teacs.

That said settop boxes (and tvs) can fail after a few years when the capacitors go bad.

that said, if you've on the cliff edge signal wise, and the sharp works but breaks up from time to time, likely it is the difference in quality between the two sets.  Two tvs can even come off the one production line, one super sensitive, the next one's a dog (even with big companies which shall remain nameless).

If you have no sbs and unstable reception, it's time to get a dude out there.

MTV seems to know his stuff and I also do antenna work too based in Frankston.  So I know the area (Pakenham can be ... not always a bad reception spot (it's quite hilly).

bobsi18, on Oct 1 2008, 10:43 PM, said:

Sorry - newbe - am not sure where to post this, so here goes:

Am just out of Pakenham 3810.  Over the years, on our old tv, we have had good reception on channels 7 and 9, decent reception on 10, ok reception on 2 and poor (sometimes none) reception on channels 28 and 31.

We have just bought 2 new tvs: a sharp 42" aquos (lc-46d63x) and a "pangoo"  lcd (LT22s18) [clive peters new cheapo brand].

On the sharp, channels 7 and 9 (both digital and analog) are great - we can't get any of the other channels on digital, the analog channel's are coming in a bit better than they used to.

On the pangoo, we can only get channel 7 on digital, and extremely poor analog reception for channels 7, 9 and 10.  Channel 2, 28 and 31 don't appear at all.

So - first off, why the difference between the sharp and the pangoo?  They are in the same place, I'm just using the same aerial - I'm just switching the cabel between the two.

Secondly, should we be looking at a new antenna?  Any recommendations for brands/types and installers around this area (south east melbourne).  (Forgive me for the next bit, I really am a newbe...).  I've heard about boosters and amplifiers - would something like that do the trick?

Thanks for any advice all

[DAVID HAYES]

S0 MUCH INFO AVAILABLE HERE AND I DONT HAVE THE NOUSE TO UNDERSTAND MOST OF IT . IF I AM NOT IN THE CORRECT SECTION I AM SORRY. WE ARE MOVING TO ST.ARNAUD SHORTLY AND NEED TO FIND OUT WHAT SORT OF ANTENNA WE NEED TO PURCHASE. THE LOCAL  ELECTRICAL STORE HAS SHUT SO THE INSTALLER HAS MOVED ON. ENQUIRIES AROUND THE TOWN HAVE NOT HELPED MUCH. CONTACT FROM HORSHAM  / BALLARRAT AND BENDIGO  REVEALS LOCAL KNOWLEDGE REGARDING LOCAL AREA AND TOPOGRAPHY ARE IMPORTANT AND WAS UNABLE TO GAIN ANY POSITIVE INFO. WOULD BE GRATEFUL FOR ANY ASSISTANCE . PLEASE KEEP INFO BASIC AS MY KNOWLEDGE IN THIS AREA IS LIMITED .   THANK YOU.

[mtv]

David,

You will need a wideband UHF antenna like the Fracarro PU4A, Hills Hunter/Ultimax or similar phased array.

Wideband UHF yagi antennas may also be suitable, but with variable terrain in the St Arnaud area, I'd recommend a phased array, which will be suitable for either Ballarat or Bendigo signals.

Most parts of St Arnaud can receive both, but ultimately, it depends on what signals are available at your particular location.

You can be be lucky with a DIY installation, but best results are obtained from a pro installer using digital signal measuring equipment to locate the best spot for mounting the antenna and accurate alignment.

[alanh]

David,
You have a clear view path of 74 km. The direction is due south to the Ballarat transmitter at Lookout Hill.

The antenna could be a highest value of band 5 Yagi See the first post and click on the link H5. The amplfier should be a GME Kingray MHU44G. For the actual channels look at the transmitter link on the first post in this strand and check out South Central Victoria.

AlanH

[mtv]

David,

Don't buy an amp before seeing how the antenna works without one, or at least without having your available signals measured.

The masthead amp recommended by alanh is too powerful and may cause overloading, which causes dtata errors in the signal stream, resulting in NO reception.

[jrickta]

AlbyZ, on Feb 11 2009, 09:57 AM, said:

Gents,

   I have now had as close to perfect reception as I could have hoped for, living in Tyaak (3658) and receiving my signal from Bendigo.  This is my setup, in summary consists of a UHF 21-69 Phased Array (Horizontal Polarisation), MHU34F (shielded) Amplifier and a shielded passive splitter, using RG6 and F-Connectors everywhere.

  The problem I am having is that an electric fence unit is causing picture breakup everytime it zaps.  If I turn the unit off, the picture returns to being perfect.  I have already moved the unit 100 meters away, made sure its grounded well (3 x 1 meter earth stakes, 5 meters apart.  On even goes into moist soil where a water trough leaks onto the ground.  I made sure all fence connections are secure (using bolt on connectors) and the fence doesn't short out anywhere.

I have even resorted to using Ferrite cores around the TV/Media Center/Antenna connectors (Not sure how effective they would be since the RG6 quadshield would prevent the RFI from penetrating the shield. so really I would be only effective on the power cables.  The thing is that if I play CD/DVD or Hardrive media, there is no breakup, which is why I suspect the antenna is picking up the signal.

Is there a way to put a filter (I've heard of low pass, etc filters) to help with the situation?  how would I go about measuring where the signal is present (ie/  I have a Oscilloscope, could I measure it with that to give me a meanful answer to gauge what type of filter would be effective?

I have also heard of a product which has its own antenna, picks up the RFI, and injects the opposite signal into the line to remove the RFI spike.  Are these options?

Thanks,

Albert

Even though your UHF antenna is a UHF antenna it still can pick up signals out of its designed bandwidth, but with a lower signal strength.
You could try using a f type 75 ohm terminator to the VHF Input of the MHU34F and placing the jumper lead on the amp from combined to seperate, this should effectively wipe out any VHF or low freq signals going thru the amp. You should be able to get one from your local electrical wholesaler.
From my understanding, you want to try and increase your signal to noise ratio, but this will not improve your reception if the impulses are too strong causing errors in the signal. It depends where the electrical impulse noise is being induced from. Try moving your antenna to a different location.
It is hard to fault find though without proper test equipment as it mostly can be guesswork which leads to time and money spent. Even with test equipment it can be difficult, as if the impulses are intermittent and quick, can be hard to trace.
Also make sure all your connections between the wallplate and components is rg6 Quadshield with f type connections and pal plug adaptors. Or you could just use RG6 Pal plug crimps.
Also try a yagi antenna as this will have less gain in the top and bottom areas, which could further reduce the noise being picked up. Depends on your location thou as you may need a phased array to get good reception.
It depends on where the noise is being received or induced into you antenna system, and how strong the impulses are.

Anyway thats all I can suggest, just still hope u read it as your post was in feb,

Cheers,

James

[alanh]

James,
It is better to have a high gain amplifier and insert an attenuator either at the input of a masthead amplfier or if not present the input of the receiver. This is because the highest signal level down the cable makes it much more immune to the pick up of impulse noise.

MTV,
The path length of 74 km and being on the edge of the fringe area, tell me why 34 dB of gain is too much.

AlanH

[jrickta]

alanh, on Jul 27 2009, 01:23 PM, said:

It is better to have a high gain amplifier and insert an attenuator either at the input of a masthead amplfier or if not present the input of the receiver. This is because the highest signal level down the cable makes it much more immune to the pick up of impulse noise.

James said:

From my understanding, you want to try and increase your signal to noise ratio...

Having the gain up too high can also lead to low MER. Fitting an Attenuator after the amp is not going to stop the upset in signal quality, if the gain is high -> intermod distortion.
Having atten at input would over come this but then why dont you just turn the gain down? Same signal should result @ output in theory.

I was stating thou if he simply switches the amp to seperate and inserting a 75 ohm terminator to the vhf input, then this should attenuate anything in the vhf bands, which should include the electrical impulses picked up by the antenna - in theory IMO.

[alanh]

James,
It depends where the gain control is. If there is amplfication prior to the gain control then overload of the first stage of amplification may occur despite the existance of a gain control.

AlanH

[DAVID HAYES]

alanh, on Jul 27 2009, 01:58 AM, said:

David,
You have a clear view path of 74 km. The direction is due south to the Ballarat transmitter at Lookout Hill.

The antenna could be a highest value of band 5 Yagi See the first post and click on the link H5. The amplfier should be a GME Kingray MHU44G. For the actual channels look at the transmitter link on the first post in this strand and check out South Central Victoria.

AlanH

THANK YOU BOTH VERY MUCH , YOU HAVE GIVEN ME A STARTING POINT I DIDNT HAVE BEFORE. IF I MAY ASK ONE MORE QUESTION THAT WOULD BE IF A TECHNICIAN IS KNOWN TO EITHER OF YOU WHO WOULD BE UP TO DOING THE INSTALL. IF NOT WHAT SHOULD I BE ASKING OF A PERSON WHO MAY DOWN THE TRACK BE RECOMENDED TO ME . I DONT MIND PAYING TO GET THE JOB DONE BUT LIKE EVERY ONE ELSE I WOULD LIKE IT DONE RIGHT THE FIRST SO THAT A RETURN VISIT WOULD NOT BE NEEDED . ONCE AGAIN THANK YOU.

Edited by DAVID HAYES, 27 July 2009 - 06:19 PM.

[mtv]

SPAM reported

[mtv]

David,

I can do the installation for you if you wish.

You can PM (private message) me with contact details, but you'll need a minimum of 5 posts before the PM feature will work for you.

You can get your post count up HERE.

If you wish to use another installer, ensure they have a digital field strength meter/spectrum analyser that can display channel power, BER and MER (and know how to interpret the information of course)

[mtv]

alanh, on Jul 27 2009, 01:23 PM, said:

MTV,
The path length of 74 km and being on the edge of the fringe area, tell me why 34 dB of gain is too much.

AlanH

Local knowledge, Alan.

It beats theory-only information from someone who is not an antenna installer and is located 3,200 km's from the area that they are giving advice about.

[Kosana]

mtv, on Jul 29 2009, 10:39 AM, said:

Local knowledge, Alan.

It beats theory-only information from someone who is not an antenna installer and is located 3,200 km's from the area that they are giving advice about.

Col,
I need your help with my reception again.
Can you give me a call on (03)54226783

Thanks,

Clive

[Honle]

Hi everyone!
I used to lived in Melbourne for 10 years, now i living in Vietnam. I'd like to ask if i can watch Australia channel such as channel 9,7, SBS from out side Australia, and can i get it . I'm using sattelite for my TV now (80 cm). Any of you guys know the frequency of any channel from australia that i can get from outside Australia. Email me if any of you guys knew it Honle@yahoo.com
  Thanks

[mtv]

Honle, on Aug 20 2009, 03:20 PM, said:

Hi everyone!
I used to lived in Melbourne for 10 years, now i living in Vietnam. I'd like to ask if i can watch Australia channel such as channel 9,7, SBS from out side Australia, and can i get it . I'm using sattelite for my TV now (80 cm). Any of you guys know the frequency of any channel from australia that i can get from outside Australia. Email me if any of you guys knew it Honle@yahoo.com
Thanks

The Australian satellite footprint does not extend north of the equator.

You can see the footprint HERE.

The metro commercial networks are only available off satellite in Australia via a valid Foxtel subscription anyhow.

ABC and SBS are available freely off satellite, but once again, not in Vietnam.

So to sum it up.... can you receive them in Vietnam?... No.

[alanh]

Honie,
Australia Television

AlanH

[eleceng]

[quote name='alanh'
[/quote]

Reception case study Tarnagulla

My parents complained of break up of Prime only, especially at night but quite variable. They had bought their first digital TV, a Sanyo 37" from Woolies. Tarnagulla is 50km from Mt Alexander. In this case, there is hills and trees in the line of site.
They had bought a new antenna, band 4/5 I think, long yagi with corner reflector. It was mounted about 10m off the ground onto the roof. RG6 all the way and a Kingray masthead amp. Don't know the model, sorry. I have a Tektronix spectrum analyser so I measured signal at wall socket. It was 61-62 dBuv at 550MHz and this is with amplifier operating. I hooked up a temporary antenna, a small Phase-Link on a poll so I could try and locate a better signal strength in the vicinity of the other antenna. I found not much difference in horizontal position but gained about 6dB in a position exactly 2 metres lower than the fixed antenna.
So it was out with the angle grinder to trim the pole.

After this was done, sure enough we had about 68dBuv into the TV and a rock steady picture. Found another 3dB with amplifier trimpot and re-guyed the mast.

No complaints now.

Moral of the story, consider heights lower too. If I did not have a spectrum analyser I don't know how we would have possibly diagnosed this.

[mtv]

eleceng,

A perfect example of how critical antenna mounting location can be, when even small adjustments to antenna position (including up/down) can make a huge difference.

Without instrumentation, that 'sweet-spot' usually can't be found.

Remember though, that the most important measurements with digital reception are BER/MER, which directly relate to the signal quality, which determines the reliability of reception.

Whilst signal strength is still important with digital, low BER and high MER is the most important.

Edited by mtv, 10 September 2009 - 05:29 PM.

[eleceng]

Remember though, that the most important measurements with digital reception are BER/MER, which directly relate to the signal quality, which determines the reliability of reception.

Whilst signal strength is still important with digital, low BER and high MER is the most important.
[/quote]

I fully agree, that is good advice. In my case, I only had access to a non-specialised general purpose RF spec-an, so BER measurements were out of the question.
I knew that at least maximising the signal would mean a probable improvement, The ground in the area is full of ironstone too, making reception even harder, including reflection risks.

I am an engineer, not an installer and I believe people in these ultra fringe areas should engage the services of reputable installers. Yes, it will cost a bit more than a city installation but done once done right is much more satisfying in the long run.

Of course there is the problem I have seen in country towns where installers from say Bendigo won't come out unless they have at least two jobs.

BTW, do you know a dBuv level into the tuner that is considered standard for digital video?

Edited by eleceng, 10 September 2009 - 08:14 PM.

[charlesc]

eleceng, on Sep 10 2009, 08:13 PM, said:

BTW, do you know a dBuv level into the tuner that is considered standard for digital video?

A level around 55dBµV for digital is generally considered OK.  For analogue it was higher, more like 60-65dBµV.

The dba.org Guide docs in my signature below expand a bit on this, and cover what is generally required for reliable digital reception.

Extract:-
"The rule of thumb developed with experience in analog reception of 1mV or 60dBµV as an aim for a  successful  analog  installation,  has  a  potential  equivalent  for  digital  TV  reception  of  0.5mV  or 54dBµV as a rule of thumb for a successful digital installation.
This guide for the digital signal level is ONLY OK IF the analog service in the presence of the digital service is of fair quality. That is, the analog service only has moderate ghosting and little interference".


Note also that a 6dBµV change gives a doubling or halving of the signal level, depending whether it is increasing or decreasing.

[mtv]

eleceng, on Sep 10 2009, 08:13 PM, said:

BTW, do you know a dBuv level into the tuner that is considered standard for digital video?

55dBuV is considered a 'standard' digital level, but I prefer 65dBuV for a greater margin.

[charlesc]

eleceng, on Sep 10 2009, 08:13 PM, said:

...dBuv level into the tuner ..

And not to forget the other end of the scale that is important too.  The 'maximum' level.

Again, generally considered to be around 77dBµV into a digital receiver.  
And this applies to any signal, analogue or digital.  Culprits here often include ABC CH2 analogue, and FM radio.

Receivers have an operating window within which they are designed to work.  Not too strong, not too weak.


Personally I'd also probably go with a higher level of 'preferred' signal towards 65dBµV as mtv mentioned.
STBs certainly perform differently, and some may well perform better when there are signal impairments if they have a stronger signal going into them.  Just watch the overload situation.


The figures above are guidelines only.  They can and will vary for quite a few reasons.

[countrychick]

Hello Country Vic!!

I live in Kerang. I have a set top box that worked fine. Then it jammed on sbs. so I would retune  the set top box and every thing was fine. I added GO with no problems. I have been away for several weeks. No channel works. I can get very and I mean very weak pics on the tv without the set top box.

how do I know if the issue is my set top box ~ which cannot find a station or my antenna ( can't spel the other word) if it is my reception then does the techno wiz need to come inside the house to fix it?

Thank you