Full Freeview on the Rowridge (Isle Of Wight, England) transmitter
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The symbol shows the location of the Rowridge (Isle Of Wight, England) transmitter which serves 620,000 homes. The bright green areas shown where the signal from this transmitter is strong, dark green areas are poorer signals. Those parts shown in yellow may have interference on the same frequency from other masts.
Are there any planned engineering works or unexpected transmitter faults on the Rowridge (Isle Of Wight, England) mast?
Rowridge transmitter - Rowridge transmitter: Possible effect on TV reception week commencing 27/11/2023 Pixelation or flickering on some or all channels 
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Digital television services are broadcast on a multiplexes (or Mux) where many stations occupy a single broadcast frequency, as shown below.
64QAM 8K 3/4 27.1Mb/s DVB-T MPEG2
DTG-12 QSPK 8K 3/4 8.0Mb/s DVB-T MPEG2
H/V: aerial position (horizontal or vertical)
Which Freeview channels does the Rowridge transmitter broadcast?
If you have any kind of Freeview fault, follow this Freeview reset procedure first.Digital television services are broadcast on a multiplexes (or Mux) where many stations occupy a single broadcast frequency, as shown below.
64QAM 8K 3/4 27.1Mb/s DVB-T MPEG2
DTG-12 QSPK 8K 3/4 8.0Mb/s DVB-T MPEG2
H/V: aerial position (horizontal or vertical)
Which BBC and ITV regional news can I watch from the Rowridge transmitter?
BBC South Today 1.3m homes 4.9%
from Southampton SO14 7PU, 26km north (354°)
to BBC South region - 39 masts.
ITV Meridian News 0.9m homes 3.6%
from Whiteley PO15 7AD, 24km north-northeast (20°)
to ITV Meridian (South Coast) region - 39 masts.
All of lunch, weekend and 50% evening news is shared with all of Meridian plus Oxford
Are there any self-help relays?
| Portsmouth Docks | Transposer | 2 km N city centre | 50 homes Estimate. Group of houses' |
How will the Rowridge (Isle Of Wight, England) transmission frequencies change over time?
| 1950s-80s | 1984-97 | 1997-98 | 1998-2012 | 2012-13 | 2 May 2018 | ||||
| VHF | A K T | A K T | A K T | A K T | W T | ||||
| C3 | BBCtvwaves | ||||||||
| C21 | C4waves | C4waves | C4waves | +BBCB | BBCB | ||||
| C22 | +ArqA | ArqA | |||||||
| C24 | BBC2waves | BBC2waves | BBC2waves | BBCA | BBCA | ||||
| C25 | SDN | SDN | |||||||
| C27 | ITVwaves | ITVwaves | ITVwaves | D3+4 | D3+4 | ||||
| C28 | ArqB | ArqB | |||||||
| C29 | LSO | ||||||||
| C31 | BBC1waves | BBC1waves | BBC1waves | com7 | |||||
| C37 | com8 | ||||||||
| C55tv_off | com7tv_off | ||||||||
| C56tv_off | COM8tv_off |
tv_off Being removed from Freeview (for 5G use) after November 2020 / June 2022 - more
Table shows multiplexes names see this article;
green background for transmission frequencies
Notes: + and - denote 166kHz offset; aerial group are shown as A B C/D E K W T
waves denotes analogue; digital switchover was 7 Mar 12 and 21 Mar 12.
How do the old analogue and currrent digital signal levels compare?
| Analogue 1-4 | 500kW | |
| PSB1||, PSB1≡, PSB2||, PSB2≡, PSB3||, PSB3≡ | (-4dB) 200kW | |
| COM4≡, COM4||, COM5≡, COM5||, COM6≡, COM6|| | (-10dB) 50kW | |
| com7≡ | (-13.1dB) 24.4kW | |
| Mux 1*, Mux 2*, Mux A*, Mux B*, Mux C*, Mux D* | (-14dB) 20kW | |
| com8≡ | (-14.3dB) 18.4kW | |
| LSO≡ | (-17dB) 10kW |
Local transmitter maps
Rowridge Freeview Rowridge DAB Rowridge TV region BBC South Meridian (South Coast micro region)Which companies have run the Channel 3 services in the Rowridge transmitter area
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Tuesday, 19 February 2013
Roy Barton: Yagis and logs work on different principles.
See:
Aerials, TV Aerial and Digital Aerial
The yagi focuses the signal onto the "active" element (the dipole).
With a log, each element acts to receive at a different frequency.
Google log periodic antenna. There are two booms and they are parallel and perhaps a centimeter apart.
Log-periodic antenna - Wikipedia, the free encyclopedia
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J
jb389:25 PM
Roy Barton: With regards to the test you have carried out, although I do not wish to appear as a prophet of doom but I can tell you if the quality of the signal regularly takes a dive in the evenings then this is NOT the type of problem that's easily rectified as it indicates that the signal received is dependant on a level of atmospheric reflection.
That said, its absolutely essential that you alter the polarity of your aerial as a proper assessment of the situation cannot be made unless this is carried out, because the atmospheric induced aspect might not be so evident if the aerial is orientated to suit the higher powered signal from Rowridge.
By the way, the bursts of quality that you get now and again is caused by the main beam of the signal being reflected off some distant moving object that happens to be passing at precisely the correct angle, such as a high flying plane or a large aluminium sided vehicle like a furniture removal van or similar, its something that happens all of the time but mainly goes unnoticed.
If altering the polarity of the aerial results in a better level of reception then I would take the advice given in Jamie's 4.13pm posting concerning the aerial being tried in different positions to the left and right of where presently installed, as this is a something I "always" advocate myself as in many cases its far more effective than increasing the height which in many cases can actually make things worse.
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Wednesday, 20 February 2013
R
Roy Barton2:49 PM
Wimborne
Roy Barton:
I appreciate all the comments. For me the matter is a case of technical curiosity. For a couple of days now I have left the TV on monitoring signal strength and signsal quality. The problem only became evident a few months back and has gotten signifcantly worse over the last few weeks. Yesterday the signal quality was consistently good fluctuating a little around 40% to 60% for six hours or so. Then later in the day the signal dipped to zero returning hours later for periods of a an hour or so to 20% to 30%. (20% is the threshold for getting a good picture.) All this time signaal strength was 90% to 99% as opposed to signal quality.
This morning the signal strength started out at 90% but quality around 10% and soon the signal strength and signal quality both dipped to 0% and has stayed like this for four hours or so.
I have been checking the above results with a second TV and that gives good agreement.
I am not an expert but the above seems to be weather or atmosphere related. None of the observations were made in windy or rainy conditions.
We live in forest well away from traffic. There is not much in the way of buildings. There are the pylon wires between us and Rowridge.
As far as I know the neighbours do not seem to be having problems.
Later today I will start experimenting with different aerial arrangements.
I don't want to be a pain... My later posts are mainly driven by technical curiosity on this wonderful forum. I have a satelite dish installed which I have not used for years and if all else fails I will upgrade that with new kit that I have packed away.
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Roy's: mapR's Freeview map terrainR's terrain plot wavesR's frequency data R's Freeview Detailed Coverage
Roy Barton: As I say, I'm not a professional, but perhaps it might be worth checking that there isn't water/damp getting in.
The other possibility is that some vegetation has grown and is affecting your signal. Jamie's suggestion of looking at moving the aerial might be worth a try if that is what it is.
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R
Roy Barton6:22 PM
Wimborne
I just tried some experiments with the new wideband aerial (£40 worth but £18 with the special offer) I also tried a very old simple aerial with 18 elements (that I had laying about) presummably group A. I get the impression that the old group A easily outperformed the wideband. (It was much easier to handle being less than a quarter of the weight.)
I was amazed to find the group A aerial being held out of any window pointing down to the ground in a any direction gave a good picture on CH28 (film4). (Our problem channel)
This test was carried out at 5.30PM.
I then checked on the main TV with the good signal strength meter still connected to the aerial on the roof that I have not disturbed.
ON switch on, the signal strength was 99% and the quality 99%. half an hour later the signal strength is still 96% and the quality is 96%
This is after signal strengths and signal quality of 0% or 1% for a whole 8 hours earlier today with perhaps jumping up to around 10% for the odd few seconds.
To my inexperienced mind this sort of inconsistency points to atmospherics (as mentioned by JB38. )
The fact that transistions from good to bad are so very clean makes me wonder if somebody is switching channels or transmitters on or off somewhere. When I spoke to the Freeview chap he hinted at some such possibility, but I did not really follow what he was saying.
During these initial trials the signal strength was so good I could not distinguish between V and H with these aerials.
But I removed the dipole from the wideband aerial and without any directors I think there was a slight improvement in V compared to H. The key thing here is that the simplest low gain aerial (ie the dipole_ gave a perfectly good picture (on a good day.)
I hope I am not boring people with these observations. I will stop if you want me to stop mentioning these anomolous results. Wide variations from day to day and hour to hour. Some periods of a signal on the weakest channel as beyond perfect, followed by periods of a signal that is reported as non existent.
After more than 50 years of owning TVs I have never come across this.
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Roy's: mapR's Freeview map terrainR's terrain plot wavesR's frequency data R's Freeview Detailed Coverage
K
KMJ,Derby9:31 PM
Roy Barton: If the problem, at least in part, is interference from Stockland Hill, it is quite likely that better results could be obtained from an aerial pointed out of the window compared with one mounted on the chimney, which although capable of receiving a stronger signal from the desired transmitter could also be subject to a stronger signal from the interfering transmitter. It is the nature of digital reception that the interference at a very low level could be ignored, but when it increases slightly to the critical level that is able to block the required signal there will suddenly be no reception. This is in contrast to analogue reception when an interfering transmission was displayed as slight patterning on the normal picture. Increases in the strength of the interference simply degraded the picture further, until in extreme cases it replaced the normal reception with the out of area signal. Your observations with the grouped aerial out performing a wideband are quite usual. In fact some of the cheaper wideband aerials appear to be a group A dipole coupled to a set of group c/d directors. Even with more scientifically constructed arrays the directors must be short enough to work at higher frequencies, making them inefficient on group A channels.
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J
jb389:34 PM
Roy Barton: I find your reports on observations made regarding signal levels / quality of and the results of subsequent tests carried out to be very informative as they are inclined to indicate that you reside in an area where the all year round reception of Rowridge with an aerial in one fixed position "might" not be possible, although only time would tell on that one.
With regards to what Dave Lindsay has mentioned regarding the possibility of water etc having entered you aerial terminations, although admittedly this is capable of causing the type of problem you are experiencing but NOT if you have noticed a reasonably consistent time factor involved when the quality dives, as this is atmospheric involvement.
However your test using only the dipole section from the aerial rather indicates that anything of a high gain (and highly directive nature) is not the type of thing to use, not of course that I would recommend these type of aerials anyway in situations such as yours, but does suggest that a log aerial such as even a DM log carefully positioned would most probably give excellent results, log aerials being relatively easy to position and with the one mentioned only being 2' 9" long and a maximum of 14" wide on the rear element, this corresponding to the lowest channel.
By the way, Doug Cheney's 4.45pm posting regarding his satisfaction with the log that was installed in his property, Doug is roughly at the same distance from Rowridge as yourself but on a bearing of 107 degrees whereas you are on 114 degrees.
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Thursday, 21 February 2013
J
jb3812:17 AM
Roy Barton: Although what KMJ has said regarding Stockland Hill (@ 50 miles / 267 degrees) is always a possibility albeit in my opinion somewhat remotely, however I had already discounted that possibility purely because this stations commercial channels are not indicated as being receivable at your location, and should by any chance they were they would be received at 27 degrees out from being a reverse pick up on your aerial, plus the other aspect of Stocklands Ch28 transmitting @ 25 Kw with a negative offset, but though one never knows!!
The other point I had previously meant to mention being, that everything said is assumed that you are actually aware that the commercial channels from Rowridge are indicated as only being able to provide a variable level of reception in your area even although radiating with an ERP of 200Kw, and although any predictions given have always to be taken with the proverbial pinch of salt what you have reported from observations made does somewhat fit in with the predictions given.
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R
Roy Barton4:56 PM
Wimborne
After some experimentation and lots of observations I have reached some tentative conclusions.. I dont really understand the underlying causes.
At our house Channels 21 22 24 25 & 27 are always rock steady with the TV reporting perfect signals 99% strength and 99% quality.
Channel 28 is sometimes rock steady for long periods at 99%/99% (perfect) Then after hours of perfect reception the signal can dip to 0%/0% (absent) and remain as such for hours. Or it will slide abruptly into wildly fluctuating signals varying rapidly between 20% to 80% quality sometimes when the signal strength is showing at 97% to 99%.
These changes seem to be at random. The changes are independent of observable weather.
There are tree branches in the line of sight but it is unlikely that much has changed in the winter months. The problem has only been evident over the last couple of months. (For the past few years signal interruption has been very rare.) I will check to see if the snow brought any branches significantly lower.
Other conclusions. While signal is wildly fluctuating the randomness has made it impossible to conclude for sure that V is better than H. (The above observations in this post refer to the old H aerial on the roof.) However the information available shows V is generably best for channels including 28. (All the neighbours have H.)
The randomness will make it impractical to get in an aerial rigger on our difficult roof to finally resolve the issue.
The great mystery is what is so different about channel 28 ???
The wideband aerial that I just purchased is obviously a waste of space. I cant understand why these expensive aerials are stocked in preference to inexpensive group aerials. (Is it a scam?)
I very much appreciate all the help from people on this forum.
I guess that if the problem persists I will dig out my new sat kit that I never found time to rig up.
Seems crazy as I finish this post the signal readings on channel 28 are rock steady at strength 97% and quality 99% and have been for the last hour. Crazy.
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Roy's: mapR's Freeview map terrainR's terrain plot wavesR's frequency data R's Freeview Detailed Coverage
M
Mazbar5:17 PM
Roy Barton: you quote signal strengths but tv signal strengths meters are rubbish to check it properly you need a proper meter. I went to a customer yesterday the tv said 28% signal but my meter said 40 dbuv dropping lower when I left the signal was 60 dbuv but the tv was saying 35% get someone in so it can be checked properly.
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