Reply With QuoteAntennas inside roofs suffer from a lot of reflections, which degrades signals (increases BER & lowers signal level).
They can work 'sometimes'.
They don't work with metal roofs or if there is foil insulation under tiles.
You guys sure know your stuff!
Thanks mtv and the rest of you. I will purchase the Variable Attenuator for starters and fingers crossed this resolves the issue otherwise perhaps my own aerial inside roof would be the next step?
Have a good weekend chaps.
Antennas inside roofs suffer from a lot of reflections, which degrades signals (increases BER & lowers signal level).
They can work 'sometimes'.
They don't work with metal roofs or if there is foil insulation under tiles.
So, from mySwitch, it looks as though the signal you have posted details for comes from possibly Noosa/Tewantin: (with a 5Hz frequency error.SIGNAL: [.................................] (100%) BER: 138 FREQ: 627499995 Hz LOCKED: YES BW: 7 Mhz)
I'd be trying a variable attenuator first as well in lieu of any system measurements, although, depending on how well engineered the distribution system is, this may not prove much. As already mentioned, were a competent tech to whack a meter on your signal at the outlet, they would be able to work out what was happening straight away.404233/Optus/Broadcast Site Sunrise Rd TEWANTIN
SSQ 7 627.5 42 V DA 1160447
I have seen poorly designed distribution systems operating in areas of multiple transmitter activity, where all channels, wanted & unwanted, are allowed to be distributed around the site. This can cause the issue you have encountered. Ideally, only the channels of interest should be selected by filtering, & then sent through the distribution system.
It looks like you might be doing some kind of automatic tune based on the number of channels you are receiving. You may need to manually tune for the transmitter of interest - is there someone you can ask as to which transmitter you should be tuning to? Methinks it should be the closest one located Peregian Beach. (However, I don't know when this transmitter started operation, so it could be your signal is coming from another transmitter solely because of historical conditions.)
I mention this, as there are transmitter sites operating on the same frequency where you are located, this in itself can lead to a whole raft of issues in itself. The frequency you posted is available from 2 transmitter sites (Noosa/Tewantin & Gympie) where you are - this in itself would be ringing cautionary alarms in my head even before I started to take measurements if I came across it in my travels.
Never stand under a shadow that's getting bigger
Ok now im a bit lost. All of a sudden the local terrestrial channels are working perfectly and i have not done anything since Friday! I was going to purchase on of the suggested Variable Attenuator's today but wonder if i will still require one?
Is it possible my signal frequancy jumps from (Noosa/Tewantin & Gympie) automaticall and i need to manually tune into one or the other for each of the local channels? I will not touch it for a couple day to see what happens and let you guys know. Should i run any tests as previously to check frequencies currently in use?
Chat soon.
May I suggest that if all is working 'normally' leave it be because you wont find any problems to fix.
Here I would err to the old adage of 'If it aint Broke, dont Fix it' and fingers crossed it will stay so.
I would also put off buying the attenuator for the time being but if the problem occurs again, you know where to start at least.
I would follow MTV's advise about not placing any antennas inside a roof as he and antennaman are both qualified in this field as they do it for a living and they have forgotten more than this bum amateur will ever know.
I stand unequivicably behind everything I say, I just dont ever remember saying it !!
Signals vary all the time, so what you have now may not stay that way.
Yes, it's possible with signal variation that one transmission site becomes better than another, especially when they share a SFN (Single Frequency Network).
SFN's can be very tricky to manage at times, even for professionals.
The correct antenna, aligned accurately to maximise only one transmission site is crucial.
Digital signals have an operating 'window' and any deviation above or below that operating window can cause issues.
It remains unknown what your signals are doing and what, if any, other signals on the distribution system are contributing.
It's impossible to know without professional signal measuring equipment connected to 'see' exactly what is happening.
With the right gear (and operator) you get a very fast diagnosis.
Never stand under a shadow that's getting bigger
how good is the connector on your antenna lead?Originally Posted by skimitchell
or maybe the cable was routed alongside power cables before at the back of the cabinet and is now separated.
Might have been just enough interference to play up
I have not touched a thing to se how things go.
All does seem fine for the most part however yesterday around 7:30pm (yes during The Bachelor) "my wife!" noticed pretty bad pixels. I did have a cloud backup running on one of my computers but this should not effect the terrestrial channels so think it must have just been the frequency jumping (Noosa/Tewantin & Gympie). It came good about 15 min later before The Bachelor rose ceremony so i am safe and wife rather understanding! :>
If it happens again i will spend the $10 and test out one of the Variable Attenuator.
Posting Permissions
Bookmarks