Page 1 of 3 123 LastLast
Results 1 to 20 of 48

Thread: wierd channel 7 problem in perth HELP please

  1. #1
    Senior Member
    carjackma's Avatar
    Join Date
    Oct 2009
    Location
    perth
    Posts
    596
    Thanks
    914
    Thanked 336 Times in 217 Posts
    Rep Power
    232
    Reputation
    4350

    Default wierd channel 7 problem in perth HELP please

    Is there any one here who is in the antenna business to help me with advice ?
    I have been having problems with the channel 7, 7two etc for no reason it will have no signal
    this has been going on for about 6 or so weeks until I got p****d off with it decided to change cables fine one day gone the next bought a fancy italian antenna from sciteq peaked it got 90% sig 100% quality thought YAHOO fixed it no yesterday it did it again all other channels are fine just poxy 7 and its the channel thats recorded the most,and whats wierd when it plays up the other channels still have exactly the same sig/quality nothing changes..
    I know its not the set top box because the tv does it as does the other tvs in the house. I am open to any suggestions please?? is there anything that could interfere with it? its freq is 177.500 .



Look Here ->
  • #2
    Administrator
    mtv's Avatar
    Join Date
    Apr 2008
    Posts
    18,028
    Thanks
    5,299
    Thanked 11,732 Times in 5,778 Posts
    Rep Power
    4149
    Reputation
    170331

    Default

    Without being there looking at the spectrum analyser, it's almost impossible to tell as the signal measurements you have mean very little as they have no benchmark. eg: what is 90% signal strength equal in dBuV? The same with signal quality... what is 100% in BER and MER?

    There can be numerous causes of why one frequency is affected more than others.

    Firstly, which suburb are you in?

    What antenna are you using and where and how is it mounted?

    How many outlets are in the house (incl any not being used)?

    Are there any signal amplifiers or powered splitters used?

    Is the coax well-shielded.. eg: RG6 Quadshield?

    Are the TV's all different brands?.... any LG or Samsung?

    Here's an odd one.... do you have a computer case with an Antec brand fan or power supply?

  • The Following User Says Thank You to mtv For This Useful Post:

    carjackma (16-09-11)

  • #3
    Premium Member

    Join Date
    Jan 2008
    Location
    Central Tablelands of NSW
    Age
    77
    Posts
    13,824
    Thanks
    1,242
    Thanked 3,803 Times in 2,523 Posts
    Rep Power
    1745
    Reputation
    56926

    Default

    Have you checked around you to see if those close to you are experiencing any reception problems?
    Are you in a house,unit,caravan or a thatched hut (sorry) but all info helps.

    MTV just made me think, have you tried each TV on its own, disconnect the others (coax & power lead) and IF that one works, add a TV one at a time and see what happens.
    Consider doing this with other appliances too.
    You have nothing to lose but your temper trying this.
    Last edited by gordon_s1942; 16-09-11 at 01:31 PM.
    I stand unequivicably behind everything I say , I just dont ever remember saying it !!

  • The Following User Says Thank You to gordon_s1942 For This Useful Post:

    carjackma (16-09-11)

  • #4
    Senior Member
    carjackma's Avatar
    Join Date
    Oct 2009
    Location
    perth
    Posts
    596
    Thanks
    914
    Thanked 336 Times in 217 Posts
    Rep Power
    232
    Reputation
    4350

    Default

    Quote Originally Posted by mtv View Post
    Without being there looking at the spectrum analyser, it's almost impossible to tell as the signal measurements you have mean very little as they have no benchmark. eg: what is 90% signal strength equal in dBuV? The same with signal quality... what is 100% in BER and MER?

    There can be numerous causes of why one frequency is affected more than others.

    Firstly, which suburb are you in?

    What antenna are you using and where and how is it mounted?

    How many outlets are in the house (incl any not being used)?

    Are there any signal amplifiers or powered splitters used?

    Is the coax well-shielded.. eg: RG6 Quadshield?

    Are the TV's all different brands?.... any LG or Samsung?

    Here's an odd one.... do you have a computer case with an Antec brand fan or power supply?

    Firstly, which suburb are you in? Camillo WA 6111

    What antenna are you using and where and how is it mounted?

    and its mounted on a pole on the roof

    How many outlets are in the house (incl any not being used)? this antenna had 3 outlets and splitter its now only on one tv splitter removed

    Are there any signal amplifiers or powered splitters used? no

    Is the coax well-shielded.. eg: RG6 Quadshield? rg6 quad

    Are the TV's all different brands?.... any LG or Samsung? yes soniq, lg ,panasonic and a fetch tv box

    Here's an odd one.... do you have a computer case with an Antec brand fan or power supply No


    I had a guy come with a meter last weak he didnt give me the BER etc but said signal was well within requirements.
    the signal i am quoting is on the tvs signal meter

  • #5
    Senior Member
    carjackma's Avatar
    Join Date
    Oct 2009
    Location
    perth
    Posts
    596
    Thanks
    914
    Thanked 336 Times in 217 Posts
    Rep Power
    232
    Reputation
    4350

    Default

    Quote Originally Posted by gordon_s1942 View Post
    Have you checked around you to see if those close to you are experiencing any reception problems?
    Are you in a house,unit,caravan or a thatched hut (sorry) but all info helps.

    MTV just made me think, have you tried each TV on its own, disconnect the others (coax & power lead) and IF that one works, add a TV one at a time and see what happens.
    Consider doing this with other appliances too.
    You have nothing to lose but your temper trying this.
    Hey there,
    Yes I have tried all the normal stuff each tv on its own add them one at a time
    still no joy.
    The funny thing its intermittent , its fine now (and its raining)
    and its only channel 7.
    when the tv guy came out it wouldnt play up.
    asked the neighbor hes having a similar problem but with abc channel 2 etc

  • #6
    Senior Member
    carjackma's Avatar
    Join Date
    Oct 2009
    Location
    perth
    Posts
    596
    Thanks
    914
    Thanked 336 Times in 217 Posts
    Rep Power
    232
    Reputation
    4350

    Default

    Quote Originally Posted by carjackma View Post
    Hey there,
    Yes I have tried all the normal stuff each tv on its own add them one at a time
    still no joy.
    The funny thing its intermittent , its fine now (and its raining)
    and its only channel 7.
    when the tv guy came out it wouldnt play up.
    asked the neighbor hes having a similar problem but with abc channel 2 etc
    Had a chat with my brother (he lives around the corner) he to is having a prob with abc ?
    me its channel 7

  • #7
    Junior Member
    Join Date
    Mar 2009
    Age
    59
    Posts
    76
    Thanks
    0
    Thanked 4 Times in 3 Posts
    Rep Power
    135
    Reputation
    30

    Default Same Thing Here

    Seven seems to have this problem every now and then for me as well. I'm in West Perth.

    It's not all the time, but some days the signal for seven is just worse than the others. Doesn't seem to correlate with the weather, time of day or anything else as far as I can tell.

  • The Following User Says Thank You to dogknees For This Useful Post:

    carjackma (16-09-11)

  • #8
    Administrator
    mtv's Avatar
    Join Date
    Apr 2008
    Posts
    18,028
    Thanks
    5,299
    Thanked 11,732 Times in 5,778 Posts
    Rep Power
    4149
    Reputation
    170331

    Default

    Having a look at the signal path, it may be blocked between you and the transmitters.

    The LP34 is a great antenna and generally fine for good signal areas.

    Did the installer perform a full site survey to determine the best mounting location and height for the antenna?

    Did the installer test various antennas before deciding on the LP34?

    It's possible you (and your brother) have multipath signals (reflections).

    It's a pity you didn't have the pre-viterbi BER, MER and RS measurements.

    Ho do your analogue channels look.... ghosting? (the LP isn't designed to receive ABC Ch2 analogue, so I expect that channel to be poor)

  • The Following User Says Thank You to mtv For This Useful Post:

    carjackma (16-09-11)

  • #9
    Senior Member
    carjackma's Avatar
    Join Date
    Oct 2009
    Location
    perth
    Posts
    596
    Thanks
    914
    Thanked 336 Times in 217 Posts
    Rep Power
    232
    Reputation
    4350

    Default

    Quote Originally Posted by mtv View Post
    Having a look at the signal path, it may be blocked between you and the transmitters.

    The LP34 is a great antenna and generally fine for good signal areas.

    Did the installer perform a full site survey to determine the best mounting location and height for the antenna?

    Did the installer test various antennas before deciding on the LP34?

    It's possible you (and your brother) have multipath signals (reflections).

    It's a pity you didn't have the pre-viterbi BER, MER and RS measurements.

    Ho do your analogue channels look.... ghosting? (the LP isn't designed to receive ABC Ch2 analogue, so I expect that channel to be poor)
    no I installed it myself and prior to that I installed the previous one ,
    I only replaced it because of the 7 issue until 6 weeks ago I had no probs,I called a antenna guy to test thats all not to install.
    I have clear line of sight to the transmitter and believe it or not I have a good picture on analog (not abc though) got me buggered .
    are there any alarms remotes etc that may use 177.500 ish freq? causing me grief as I said its not all the time.
    what I did find out today is they are using a new transmitter in rolystone and 7 is transmitted on that repeater around 477mhz so if I am within its range I might spin the antenna around and give it a go.

  • #10
    Administrator
    mtv's Avatar
    Join Date
    Apr 2008
    Posts
    18,028
    Thanks
    5,299
    Thanked 11,732 Times in 5,778 Posts
    Rep Power
    4149
    Reputation
    170331

    Default

    There's nothing else on 177.500MHz, however, any strong out of band signals may interfere, which is why it's important to measure all RF. especially high-power broadcast signals in the area.... something a lot of installers overlook.. they just measure the digital TV signals and nothing else.

    With line-of-sight to the main transmitters (at approx 14km away from you) it's even possible your digital signals may be too strong.

    Some LG, Samsung and Panasonic tuners have difficulty decoding overly-strong signals, both in and out of band, so if that's the case, you need to attenuate the levels.

    Once again, without accurate signal measurements, it's impossible to tell exactly what's happening.

    Antenna mounting location can be critical, not so much with line of sight, but if there are strong reflected signals reaching the antenna, they can be minimised with careful antenna placement, which needs to be done whilst checking all signals as you move the antenna around the roof.

    Higher isn't always the answer either.

    The Roleystone translators are located approx 7 km away from you, but are very low power. eg: 75 watts, compared to the main TX which are up to 200 kilowatts.

    They Roleystone channels are all in the UHF band 5 range, so you would require an antenna that covers that band. The Fracarro LP34F is only band 3 & 4. It may work, but performance would be degraded compared to an antenna designed for the frequency range.

    Only one way to find out.

    The Roleystone translators are on the following channels/frequencies:

    SBS53 704.500MHz

    ABW56 725.500MHz

    TVW59 746.500MHz

    STW62 767.500MHz

    NEW65 788.500MHz

  • The Following User Says Thank You to mtv For This Useful Post:

    carjackma (16-09-11)

  • #11
    Senior Member johnwinger's Avatar
    Join Date
    Feb 2011
    Location
    Melbourne
    Age
    37
    Posts
    942
    Thanks
    232
    Thanked 222 Times in 156 Posts
    Rep Power
    169
    Reputation
    1473

    Default

    Quote Originally Posted by mtv View Post
    Here's an odd one.... do you have a computer case with an Antec brand fan or power supply?
    What can an Antec fan or PSU cause?

  • #12
    Member
    Join Date
    Jan 2008
    Posts
    343
    Thanks
    82
    Thanked 64 Times in 44 Posts
    Rep Power
    170
    Reputation
    620

    Default

    I have/ am still having problems similar to you. To make sure it was not the antenna I put up another antenna and pointed it at another transmitter. One on vertical the other on horizontal.Using two different PVR's , I recorded the same program,same time( 7 two ). Picture broke on both at exactly the same place. Would appear that Channel 7 is transmitting the fault. Now try getting them to do something about it, I've tried and have had no luck so far.

  • #13
    Administrator
    mtv's Avatar
    Join Date
    Apr 2008
    Posts
    18,028
    Thanks
    5,299
    Thanked 11,732 Times in 5,778 Posts
    Rep Power
    4149
    Reputation
    170331

    Default

    Quote Originally Posted by johnwinger View Post
    What can an Antec fan or PSU cause?
    I Had a client a few years ago who had an issue with Ch 7 being lost totally, but on one screen only.

    All signal measurements were excellent, but 7 was wiped out, regardless of integrated tuner, or when 3 different STB's were connected.

    Eventually found the computer in the same room as the TV was the culprit.

    The case fan was multi-speed and used a pulsed-encoder to monitor/control the speed. On a particular speed, the pulses were radiating, causing interference to any DVB-T tuner nearby.

    The client was not quite convinced, even when the computer was turned off and the issue ceased. Moving the computer to another room where another TV had been working perfectly, when it too lost Ch7 was sufficient proof for the client to believe his new and expensive computer was the culprit.

    The fix was to alter the fan speed.

    It's likely it was still generating spurious emissions, but no-longer affecting the frequencies in use.

    Antec use/d the same fans in cases and power supplies.

    I had discovered a problem that had plagued TV viewers worldwide who had these fans.

    Antec were notified and hopefully, rectified the design.

  • The Following User Says Thank You to mtv For This Useful Post:

    mkhannah (28-09-11)

  • #14
    Administrator
    mtv's Avatar
    Join Date
    Apr 2008
    Posts
    18,028
    Thanks
    5,299
    Thanked 11,732 Times in 5,778 Posts
    Rep Power
    4149
    Reputation
    170331

    Default

    Quote Originally Posted by dixons View Post
    I have/ am still having problems similar to you. To make sure it was not the antenna I put up another antenna and pointed it at another transmitter. One on vertical the other on horizontal.Using two different PVR's , I recorded the same program,same time( 7 two ). Picture broke on both at exactly the same place. Would appear that Channel 7 is transmitting the fault. Now try getting them to do something about it, I've tried and have had no luck so far.
    One can never rule out a transmission problem.

    The transmission chain can (and does) have problems from time to time, so it's not always the receiving end.

    Your issue may be unrelated, dixons.

    What's your location and which two transmission sites did you point your antennas at?

    What makes/models of antennas did you try?

    The interesting thing is that carjackma's brother (living just around the corner from him) does not experience Ch 7 reception problems, but does with ABC.

    This tends to suggest the issue is with reception, more than transmission.

    I've had a few people monitoring in various Perth areas and none are reporting any transmission issues, with excellent reception from the main TX.

  • #15
    Member
    Join Date
    Jan 2008
    Posts
    343
    Thanks
    82
    Thanked 64 Times in 44 Posts
    Rep Power
    170
    Reputation
    620

    Default

    Discussed this in a previous post a while back.I live near the latrobe valley in victoria.
    Two transmitters, one in Churchill and one near Yinnar. I've been told that that they both re-transmit the signal from mount tassie and the Churchill tower re-transmits that signal to the Yinnar transmitter and another transmitter at Boolarra.Using phased array on one and Yagi on the other.Have tried the experiment a couple of times, as it appears to be getting worse, with the same results.

  • #16
    Administrator
    mtv's Avatar
    Join Date
    Apr 2008
    Posts
    18,028
    Thanks
    5,299
    Thanked 11,732 Times in 5,778 Posts
    Rep Power
    4149
    Reputation
    170331

    Default

    Quote Originally Posted by dixons View Post
    Discussed this in a previous post a while back.I live near the latrobe valley in victoria.
    Ah yes.... completely unrelated to transmission/reception in Perth WA.

  • #17
    Premium Member

    Join Date
    Jan 2008
    Location
    Central Tablelands of NSW
    Age
    77
    Posts
    13,824
    Thanks
    1,242
    Thanked 3,803 Times in 2,523 Posts
    Rep Power
    1745
    Reputation
    56926

    Default

    I think these sort of reception problems are going to occur everywhere untill the changeover is finaly completed in 2013 (Metro areas) which is why I asked if you had checked with your neighbours to see if they are experiencing problems too.
    Just because they are the Broadcasters, it doesnt mean there cant be problems either with the actual program or the transmission of the signal.
    Because it seems your getting it 'Perfect One Day, Zilch the Next' (sorry Qld) I am leaning heavily towards the problem being theirs rather than yours.
    This is where I wish these damn FSM's were both cheaper and more User Friendly to have one sitting In Line to watch (and Record) the signal over a given period.

    Although my area has had full digital for the last 2 years in tandem with the analog, who knows what alterations or adjustments will occur when the changeover begins next January.
    I believe my local translator has a seperate mast and antennea for Digital already (ACMA list) and I hope that the turning off and removal of the analog equipment will have no affect but because I am in an extreme fringe location, any variation to the signals will be very noticable to me.
    Last edited by gordon_s1942; 17-09-11 at 03:36 PM.
    I stand unequivicably behind everything I say , I just dont ever remember saying it !!

  • #18
    Administrator
    mtv's Avatar
    Join Date
    Apr 2008
    Posts
    18,028
    Thanks
    5,299
    Thanked 11,732 Times in 5,778 Posts
    Rep Power
    4149
    Reputation
    170331

    Default

    Quote Originally Posted by gordon_s1942 View Post
    Just because they are the Broadcasters, it doesnt mean there cant be problems either with the actual program or the transmission of the signal.
    Because it seems your getting it 'Perfect One Day, Zilch the Next' (sorry Qld) I am leaning heavily towards the problem being theirs rather than yours.
    Perfect one day, zilch the next is a 'perfect' example of threshold 'digital cliff' reception, or impulse noise interference, etc, not so much a transmission issue.

    Whilst it's certainly not impossible for transmission/link issues to be involved, I think it's highly unlikely as I've checked with a few people in various areas around Perth and they are not experiencing any reception problems with any of the digital channels from the main TX.

  • #19
    Premium Member

    Join Date
    Jan 2008
    Location
    Central Tablelands of NSW
    Age
    77
    Posts
    13,824
    Thanks
    1,242
    Thanked 3,803 Times in 2,523 Posts
    Rep Power
    1745
    Reputation
    56926

    Default

    A friend is experiencing just this with the ABC from Orange NSW but if we have done the maths, he is a good 60 miles from the transmitter and as MTV knows my signal is a joke but oddly I seem to be having better reception generaly than many others.
    I stand unequivicably behind everything I say , I just dont ever remember saying it !!

  • #20
    Senior Member
    carjackma's Avatar
    Join Date
    Oct 2009
    Location
    perth
    Posts
    596
    Thanks
    914
    Thanked 336 Times in 217 Posts
    Rep Power
    232
    Reputation
    4350

    Default

    Just want to say thanks to all it turned out to be too much signal.
    I have reinstalled my splitter without the booster and all is well.
    when I had only one tv or all tvs with a booster I had probs .now its installed without the booster all is good
    anway thanks again to all for your advice

  • The Following User Says Thank You to carjackma For This Useful Post:

    Aurora8 (31-10-11)

  • Page 1 of 3 123 LastLast

    Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •