Full Freeview on the Oxford (Oxfordshire, England) transmitter
Brian Butterworth first published this on - UK Free TV
Google Streetview | Google map | Bing map | Google Earth | 51.790,-1.179 or 51°47'25"N 1°10'46"W | OX3 9SS |
The symbol shows the location of the Oxford (Oxfordshire, England) transmitter which serves 410,000 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.
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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 Oxford 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 Oxford transmitter?
BBC South (Oxford) Today 0.4m homes 1.6%
from Oxford OX2 7DW, 6km west-southwest (258°)
to BBC South (Oxford) region - 6 masts.
BBC South (Oxford) Today shares 50% content with Southampton service
ITV Meridian News 0.9m homes 3.4%
from Whiteley PO15 7AD, 102km south (182°)
to ITV Meridian/Central (Thames Valley) region - 15 masts.
Thames Valley opt-out from Meridian (South). All of lunch, weekend and 50% evening news is shared with all of Meridian+Oxford
How will the Oxford (Oxfordshire, England) transmission frequencies change over time?
1950s-80s | 1984-97 | 1997-98 | 1998-2011 | 2011-13 | 2013-18 | 2013-17 | 23 May 2018 | ||
VHF | C/D E | C/D E | C/D E | C/D E | C/D E T | W T | W T | ||
C2 | BBCtvwaves | ||||||||
C29 | SDN | ||||||||
C31 | com7 | com7 | |||||||
C37 | com8 | com8 | |||||||
C41 | BBCA | ||||||||
C44 | D3+4 | ||||||||
C46 | _local | ||||||||
C47 | BBCB | ||||||||
C49tv_off | C5waves | C5waves | |||||||
C50tv_off | SDN | SDN | |||||||
C51tv_off | LOX | LOX | |||||||
C53tv_off | C4waves | C4waves | C4waves | +BBCA | +BBCA | +BBCA | |||
C55tv_off | ArqB | ArqB | ArqB | com7tv_off | |||||
C56tv_off | COM8tv_off | ||||||||
C57tv_off | BBC1waves | BBC1waves | BBC1waves | BBCB | BBCB | BBCB | |||
C59tv_off | -ArqA | -ArqA | -ArqA | ||||||
C60tv_off | ITVwaves | ITVwaves | ITVwaves | -D3+4 | -D3+4 | -D3+4 | |||
C62 | SDN | ||||||||
C63 | BBC2waves | BBC2waves | BBC2waves |
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 14 Sep 11 and 28 Sep 11.
How do the old analogue and currrent digital signal levels compare?
Analogue 1-4 | 500kW | |
BBCA, D3+4, BBCB | (-7dB) 100kW | |
SDN, ARQA, ARQB | (-10dB) 50kW | |
Analogue 5 | (-11dB) 40kW | |
com8 | (-14.7dB) 17.1kW | |
com7 | (-14.8dB) 16.4kW | |
Mux 1*, Mux 2*, LOX | (-17dB) 10kW | |
Mux C*, Mux D* | (-18dB) 8kW | |
Mux A*, Mux B* | (-19.2dB) 6kW |
Which companies have run the Channel 3 services in the Oxford transmitter area
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Sunday, 2 October 2011
B
Bill C8:24 PM
Steve P - many thanks - I wondered if that was the problem - have ordered an attenuator ...
Bill
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Monday, 3 October 2011
J
Jonathan9:50 PM
Oxford
Follow up to my posts of Wednesday 28 September 2011 10:15PM and Thursday 29 September 2011 9:40AM (lost all multiplexes except C53 on 28 September; OX4 4EY but view of Beckley blocked; wideband high gain pole mounted aerial).
I got a 0-20dB variable attenuator. Playing with (is it 20dB at fully clockwise or fully anticlockwise?) certainly had an effect but nothing simple. Turns out that the signal quality is far more strongly affected by the exact position of the aerial drop cable than anything else.
Trial and error eventually led to a position where I could get the three high power multiplexes (C53, C57, C60) but nothing else. I'm a bit reluctant to fiddle any more until I have a slightly better idea of what I'm meant to be doing...
All thoughts appreciated!
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Jonathan's: mapJ's Freeview map terrainJ's terrain plot wavesJ's frequency data J's Freeview Detailed Coverage
Tuesday, 4 October 2011
S
Spartan1:35 PM
Jonathan, you mentioned that the position of the coax feeder appeared to make a difference. Is this a fairly new installation? I'd check out the cable and see if there are any nicks or cuts in it. Is it in one single length from aerial to TV/digital box, or do you have joints anywhere? Any joints or junction boxes can be a source of problems.
Is the aerial feeding more than one TV set/recorder, etc?
Whilst I'd expect Quality to suffer rather than Signal strength, try turning off ALL appliances in the house just in case something is generating interference which may be reducing the available signal. And that includes mobile and cordless phones, WiFi Broadband router, etc.
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K
Kevin Gardiner2:23 PM
Jonanthan, looks like a classic case of signal overload here. your location is 5 miles from the Oxford ( Beckley ) transmitter. The signal strength at your location (without an aerial with no gain ),after DSO is 78db on the 100kw multiplexes and 75db on the lower 50kw multiplexes. To obtain a stable signal at the tv set, the BBC recommend a signal strength of 65db. However, most Free view set top boxes and integrated tv's have a signal strength tolerance of approx 80 db. If your signal is above this figure, you will experience signal overload, which consists of Pixelation, stuttering and freezing of the tv picture and break up of the sound, 0r no channels at all, and low signal level indication on the set top box and tv signal strength meters.
Jonathan, your aerial set-up is making the signal overload problem worse. you have a wideband aerial with an amplifier attached to it outside on a pole.This set-up was fine pre-switch-over, as the signals were all on low power.
To help resolve your problem, you need to switch off the amplifier and try re-connected the aerial to the television. Do a re-tune and see what happens. If you still have a few multiplexes missing from the channel line-up after a re-tune, then i would have a new aerial installed outdoors.The correct aerial group for Oxford is a group c/d aerial, as it resinates best on the frequencies the Oxford transmitter is using. I.E. frequency channels 53.55.57.59.60.62. To get the proper alignment to the Oxford transmitter,it is situated 28 degrees from your location. Hope that this all helps.
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S
Spartan2:57 PM
Kevin, you may well be right, but he did specifically say he had no booster, and was trying out an attenuator. So you're suggesting 20dB attentuation is not enough...?
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C
Cathy3:46 PM
Hello,
Just reporting back.
Our problem turned out to be nothing to do with the indoor aerial or signal strength but instead it was the digibox. Apparently at switchover they change the type of signal and some digiboxes can't cope with the new one. It's a shame Digital UK doesn't mention this on their publicity! We had an older Goodmans GDB3 - it wasn't on the original list of non-compatible boxes but it seems it should have been - it would have saved us the expense of buying a new aerial only to find exactly the same problem!
Anyway, all fixed now and getting an excellent signal on all Freeview channels via our indoor aerial.
Thanks for the advice.
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S
Steve P3:53 PM
Wrexham
Jonathan - dunno which way the attenuator goes - ask supplier/manufacturer? Or give details here to see if anyone knows.
If you have a good condition properly fitted properly earthed coax and a strong signal its position should not matter. So one of these does not apply. Can you describe where and how you move the coax to get changes? You do realise there will be a time delay between movement and seeing the result on the TV?
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Steve's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage
C
Chris.SE4:10 PM
Jonathan: If you look at any page on the information or setup that shows the signal strength & quality for say MUX PSB1 UHF C53 you should be able to see the effect directly as you turn it up & down.
Try setting it so that it indicates about 95% of the max strength and then see what you are getting.
You will need to do a rescan I expect. Best to do a full factory reset/new installation, first with the aerial unplugged to clear all previous setting and channels, and then do it again with the aerial plugged in.
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C
Chris.SE4:14 PM
Steve P: The Coax should NOT be earthed.
The aerial and coax installation should be "floating" and totally independant of any electrical earth.
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C
Chris.SE4:33 PM
Jonathan: by the way do you know exactly what the aerial is? Also your view of the transmitter, is it "blocked" or just not visible due to gently rising ground.
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