All posts by Derek Green
Below are all of Derek Green's postings, with the most recent are at the bottom of the page.
Stevem
I think Canford Heath is further inland than where I am, Canford Cliffs? People have often been surprised that we are almost within sight of the IOW but our road has notoriously bad reception from Rowridge.
I agree it is bad that the BBC multiplex seems now to be the one that suffers from French station interference.
I am contemplating trying to remove one or more boosters after Wednesday. Like you, I hope the power boost will be enough to minimise co-channel interference. I have FreeSat in our main viewing room, so I am luckily not too dependant upon Freeview. However, some rooms have Freeview standalone sets and not FreeSat.
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I wasn't aware until I re-read the switchover details that the Rowridge transmitter will be unusual in that it will transmit the boosted power Freeview transmissions with both Vertical and Horizontal polarisation. It would have been nice to know about that from BBC/ITV etc i.e Freeview authorities. This means that all of us who have had problems might also try mounting our aerials with either horizontal or vertical orientated elements. This is new to me and I thought I was technically aware (ex BBC engineer! long time ago!).
So try removing boosters, and also try re-orientating your aerial elements (the metal bars) to be horizontal or vertical and check the signal strength on a few stations across the range. Do it after March 21st.
Question for Freeview authorities (won't read this?) is "Was this mixed polarisation designed to minimise French co-channel interference under high pressure weather zones over Northern France?"
I hope people are reading this. This post seems to be a long way down the Rowridge page!
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Thanks to Stevem for pointing me to the A.T.V Aerials site. This is the first time I have seen the timetable so clearly produced. I will now wait until 18 April for the vertical test. It was also nice to see that the "unique" polarisation was indeed for minimising co-channel interference, just as I presumed! But it would have been nice if those in the Rowridge are had been told, or is it only the trade who find out about such things?
Thanks to Dave Lindsay for pointing out the timing too. And in answer to your question. I can get a weak analogue signal from the Parkstone relay, but it is not transmitting Freeview yet. I presume it will transmit Freeview "lite" after switchover???? Is there another Poole relay? Please enlighten me?
Kim V. Today I have had virtually perfect BBC MUX signals from Rowridge. Just a few brief bits of pixellation at lunchtime. The high pressure zone has moved away from the critical area of northern France that causes the "lifts" and co-channel interference. You may have variable gain from different frequencies from your aerial system? The move of the BBC MUX may have caused you to get a lower signal. Again, waiting until Wednesday and, now thanks everyone, April 18 for the extra power and other MUXes on vertical polarisation, will be the time to try to get things working properly?
Oh what fun!?
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Mike
I will not be able to claim any kudos, but might I be the first in Poole to have a VP aerial in my loft (unverifiable unless I give you permission to go in my loft!)?
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Nicholas
I think your answer is here
http://www.digitaluk.co.u….pdf
You have to scroll down a bit....
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Sorry to hear some of you have problems, but I am a very happy bunny!
I took my masthead and two boosters OUT and connected a portable TV to the aerial in our loft and got 61% signal strength on all stations and 100% quality. I then rotated the aerial to vertical polarisation and got 91% strength and 100% quality.
Then I wired the distribution amp back in to feed all rooms and wow all Freeview receivers work well (100+ channels). The 4 Freeview HD channels on our Sony Bravia 40inch is perfect, no breakups, solid signal.
Why have we been waiting so long?
I hope others sort out their problems soon. Try vertical polarisation? I did not expect it to be that much better. The April 18th changes will just help on some minor channels. I will not notice any difference.
Whooppeeee..........
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Quite a few have asked about changing from horizontal to vertical polarisation. I am lucky in that I have a loft aerial. It is a wideband, although this is not recommended, however, it works and if it it ain't broke it doesn't need fixing! I get enough signal now anyway.
I rotated my wideband aerial through 90 degrees so that the elements are now vertically aligned but obviously the whole thing still points towards Rowridge. All it took was to release the clamp holding the bar (which points to Rowridge)on which all the elements and reflectors (at the back) are mounted. As it is easily accessible in my loft, it took a few moments with an adjustable spanner to release the clamp, pull out the bar, twist through 90 degrees and push back in the clamp and retighten the two bolts on the clamp. All the elements are now vertical. As I said in a previous posting my personal signal strength went from 61% to about 91%, with 100% quality. I will be watching to see if the co-channel interference will be less than it used to be from the French transmitters. There seem to be some high pressure areas floating around. It may not be too long before we can all see the improvements or not?
From my background any aerial can be rotated simply in this way. I changed from roof mounted aerials to loft many years ago, having had rusting and bird damaged aerials too many times before, despite having a slightly lower signal. It is worth it because you avoid having to use a ladder or any aerial company's engineers!
Engineers should not charge much at all for rotating the aerial from horizontal to vertical polarisation if roof or chimney mounted. It should be very easy indeed. If in the loft, do it yourself?
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Sunday 18 March 2012 11:07PM
Hi Kim V,
I am in Canford Cliffs and have had problems since the first change made on 7 March. The BBC channels all have had problems, however, unusually part of this is for another reason. There has been a high pressure zone over Northern France around this time that has caused co-channel interference and break up/pixellation on BBC channels. Although theoretically I should always have had a reasonable signal, I have always had to have 3 boosters in a chain to get Freeview reception from Rowridge. The BBC changes and the weather situation caused me additional headaches, like you.
I think you should try a "factory reset" on your TV and also your TopUp box. Then try a re-scan of the Freeview channels. You should be able to find how to do the reset in manuals for the TV and box. This reset will take your equipment back to the situation when you first unpacked them from their boxes. I think you will get back a lot of your missing channels. I did. The weather situation is changing, with the troublesome high pressure zone becoming more diffuse. (You will get interference from French digital channels that use the same frequencies but only when the high pressure is south of our coast.)
You should perform the factory reset again on March 21 and another rescan for stations.
Let us know how you get on, please?