Audie Posted March 12, 2007 Posted March 12, 2007 Hi all, A question from my parents Allawah area low down south side and the signal on 7 and 9 progressively gets worse every Sat and Sun night from around 18:00 to 20:00. ONLY Ch 7 and 9. ABC seems fine and they don't watch Ch10 except for the early evening news Any suggestions? Airport interference maybe? - could it be local if it gets worse then terrible for over an hour then progressively better? I looked at the analogue picture in the middle of the problems and I'd rate it a 2 [where 0 = unviewable and 10 = perfect picture]. All help appreciated.
wahroonga farm Posted March 12, 2007 Posted March 12, 2007 R we talking analogue or digital reception? Have a look here for picture descriptions of typical analogue interference. In any case, the interference affects both transmission forms (albeit a bit differently and some more than others). As in all good signal area, it comes down to antenna selection, antenna location, and possibly selective filtering/attenuation to eliminate/minimise any interference source. Then comes cabling, splitters, stb selection and so on ......
Audie Posted March 13, 2007 Author Posted March 13, 2007 There is no digital reception on 7 or 9 during the times I quoted above. Outside of those times it's perfect. While the problem occurs, I know that ABC digital is fine. I also checked the analogue picture on 7 and 9 when the problems occured and it was about 90% snow. I'll get them to check the analogue picture against the ABC site you noted above again this Sat/Sun when it occurs. Just confirming the digital service is perfect outside of those 2 time blocks, so I'd have thought there is no major issue with their setup - more likely interference only on Sat/Sun in that time block [??].
sydney2218 Posted March 13, 2007 Posted March 13, 2007 There is no digital reception on 7 or 9 during the times I quoted above. Outside of those times it's perfect. While the problem occurs, I know that ABC digital is fine.I also checked the analogue picture on 7 and 9 when the problems occured and it was about 90% snow. I'll get them to check the analogue picture against the ABC site you noted above again this Sat/Sun when it occurs. Just confirming the digital service is perfect outside of those 2 time blocks, so I'd have thought there is no major issue with their setup - more likely interference only on Sat/Sun in that time block [??]. I am in Allawah , been Digital for 3 years . There are no local interference problems.The reception issues you have are to do with a combination of antenna, amplifier/splitter etc . As mentioned in these forums many times to receive a proper digital signal at the monitor requires a specific signal stength between 2 levels , neither too much or too little.IF you are close to too high or too low any change in atmospheric conditions, power load etc will tip off your "COMPUTER " in the STB & it will give a black screen or pixellate/break up the picture.You need to determine the relative strengths of the LCNS on VHF & UHF, as Seven is on 6 & 48 RF channels .Depending on your antenna you chose the best one .I have found the UHF from KIngs Cross is ok on Ten & Seven but not on ABC & Nine.I pick up the Artarmon VHF signals thru our Apartment block amplifier/splitter at acceptable levels.It depends on the antenna & the old amplifier settings.I need to split Seven to attentuate , a little.With a bit of luck i now get all networks at 85% + signal strength & 90%+ quality , Abc goes to 100% but does not break up.Actually i am the only one in our block who gets good digital reception .The body corporate will not upgrade the the amplifier.So as many have done in our block & nearby they watch crappy analogue on their $3000 sets!!!.Years ago they had a UHF band 5 put up for reception off the UHF at Kings Cross as GHOSTING on VHF was really bad but the Digital UHF reception from the Elan Building is not as good .Luckily the old battered VHF antenna was left in place.I wanted to reset the amplifier in the roof but not allowed.The new UHF frequencies are listed on this site & DBA website.The LCN strengths can be seen thru the Stb menu , usually in the installation section . Delete the duplicate Lcns in the favourites list , you create .If you dont delete the weak/strong LCN THAT CAUSES ISSUES i have found you risk the STB defaulting to it.Again Seven is on 6 & 48 RF .The full list is in the pinned topic.In my 3 set top boxes & PC tuner it is obvious which are the duplicates after a scan.
Audie Posted March 16, 2007 Author Posted March 16, 2007 Sydney2218: If there is no local interference in the Allawah area, any suggestions what could be causing the problems just at those 2 blocks of times? Outside those 2 blocks of times [roughly Sat and Sun 6pm-8pm] the picture is indeed free of interference. Anything you can think of locally I should follow up for them? Wahroongafarm: They followed the link you gave and they reckon 'Weak Signal' is the closest match. But why only 4 hours out of every week? Hmmm.
sydney2218 Posted March 17, 2007 Posted March 17, 2007 Sydney2218: If there is no local interference in the Allawah area, any suggestions what could be causing the problems just at those 2 blocks of times? Outside those 2 blocks of times [roughly Sat and Sun 6pm-8pm] the picture is indeed free of interference. Anything you can think of locally I should follow up for them?Wahroongafarm: They followed the link you gave and they reckon 'Weak Signal' is the closest match. But why only 4 hours out of every week? Hmmm. The problem , like many others who have posted similar problems related to a drop off at a particular time, are still to do with the signal strength & quality levels required by the STB & Digital standards.You are on the LCNS in question close to the drop off point & any slight variation in signal strength cuts off the STB PROCESSING. You need to get a professional installer to do readings & adjust your gear as advised....
Audie Posted March 17, 2007 Author Posted March 17, 2007 They're getting Tele-right out during the week [same guys did our place and VERY happy with them]. I'll be interested in their reaction to why the analogue picture also goes from great to 90% snow at those times also, and whether the readings/adjustment will fix that also at just those 2 time blocks. It's just a pity the digital signal is so strong outside of those 2 time blocks also. Thanks to you both for comments/suggestions - it's a strange one this problem.
alanh Posted March 18, 2007 Posted March 18, 2007 Audie, Is this problem related to the weather? If the antenna is old, the moisture gets into the plastic insulators and short out the signal. AlanH
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