Full Freeview on the Ridge Hill (County of Herefordshire, England) transmitter
Brian Butterworth first published this on - UK Free TV
Google Streetview | Google map | Bing map | Google Earth | 51.997,-2.540 or 51°59'49"N 2°32'25"W | HR8 2PG |
The symbol shows the location of the Ridge Hill (County of Herefordshire, England) transmitter which serves 270,000 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.
This transmitter has no current reported problems
The BBC and Digital UK report there are no faults or engineering work on the Ridge Hill (County of Herefordshire, England) transmitter._______
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
H/V: aerial position (horizontal or vertical)
Which Freeview channels does the Ridge Hill 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
H/V: aerial position (horizontal or vertical)
Which BBC and ITV regional news can I watch from the Ridge Hill transmitter?
BBC Midlands Today 2.9m homes 10.9%
from Birmingham B1 1RF, 69km northeast (39°)
to BBC West Midlands region - 66 masts.
ITV Central News 2.9m homes 10.9%
from Birmingham B1 2JT, 69km northeast (39°)
to ITV Central (West) region - 65 masts.
All of lunch, weekend and 80% evening news is shared with Central (East)
Are there any self-help relays?
Whitton | Transposer | 35 km NW Hereford | 40 homes |
How will the Ridge Hill (County of Herefordshire, England) transmission frequencies change over time?
1968-80s | 1984-97 | 1997-98 | 1998-2011 | 2011-13 | 1 Mar 2018 | ||||
VHF | A K T | A K T | A K T | W T | W T | ||||
C6 | ITVwaves | ||||||||
C21 | +SDN | SDN | |||||||
C22 | BBC1waves | BBC1waves | BBC1waves | +BBCB | BBCB | ||||
C24 | ArqA | ArqA | |||||||
C25 | ITVwaves | ITVwaves | ITVwaves | D3+4 | D3+4 | ||||
C27 | ArqB | ArqB | |||||||
C28 | BBC2waves | BBC2waves | BBC2waves | BBCA | BBCA | ||||
C29 | D3+4 | ||||||||
C30 | _local | ||||||||
C32 | C4waves | C4waves | C4waves | com7 | |||||
C34 | com8 | ||||||||
C35 | C5waves | C5waves | |||||||
C51tv_off | _local | _local | |||||||
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 6 Apr 11 and 20 Apr 11.
How do the old analogue and currrent digital signal levels compare?
Analogue 1-5 | 100kW | |
BBCA, D3+4, PSB2 iw, BBCB | (-7dB) 20kW | |
com7 | (-9.8dB) 10.5kW | |
SDN, ARQA, ARQB | (-10dB) 10kW | |
com8 | (-10.1dB) 9.8kW | |
Mux 1*, Mux 2*, Mux A*, Mux B*, Mux C*, Mux D* | (-17dB) 2kW |
Which companies have run the Channel 3 services in the Ridge Hill transmitter area
|
|
Is the transmitter output the same in all directions?
Radiation patterns withheldSunday, 15 October 2023
C
Chris.SE3:41 PM
Nick :
Hi Nick. The predictions for the COM muxes in your locale SDN/COM4, ArqA/COM5 & ArqB/COM6 are poor. How well do you normally get/are you getting COMs 5 & 6 ?
There is Planned Engineering at Ridge Hill and you may have just picked a bad moment to retune and if you did that earlier this morning there was still a little bit of this "Tropo" weather conditions about as well, but should be clear now.
What strength and quality figures do you have for the PSB muxes?
Have you got any aerial amp/splitter to feed more than one set/box? Have you got a 5G filter fitted before the amp if you have? You should have had a postcard from https://restoretv.uk
If you haven't got a filter fitted, you can get a free one from them.
link to this comment |
Wednesday, 18 October 2023
S
Steve Donaldson1:03 AM
Nick : Should you not be aware, I have made the observation that the Chalford relay broadcasts on channels 21, 24 and 27 with vertical polarity. It has been co-channel with Ridge Hill's COMs since digital switchover. This is not to suggest that it might be the cause of your reception issue.
link to this comment |
Monday, 23 October 2023
N
Nick 2:44 PM
Chris.SE: sorry Chris only just seen your reply. Where do I start in replying. Its a fairly complicated set up here, all home made! I have two aerials one for the stroud relay and a horizontal antiferance high gain for Ridge hill.
These are fed into a home made combiner which filters the two bands of frequencies. Has about half a db loss on the Ridge hill input. Just to complicate things more I have a home made amplifier (14 db)on the Ridge hill input. Then after all that mess it comes out the combiner and goes into a distribution amplifier which feeds two sets in my house and also the neighbours! There's also a tuned notch on the high side of the combiner for 4g . As for signals on the various multiplexes. Ch 22, 25, 28, 29 are all 100 signal 100 quality.
Ch 24 is variable but around 97% signal 60% quality, much the same on ch 27. They do vary considerably though, but fairly reliable. I'm not too bothered really as there's little worth watching on ch 21 multiplex. It just intrigues me! I've connected my spectrum analyzer to the system and all multiplexes are present and correct but you can clearly see the 3 lower power ones. Some one else commented that the Chalford really could be a problem, well its too weak and feeble here and cross polarised.
Tropo can cause problems but still the situation is the same now with normal propagation.
Anyway thanks for your reply and hope the above makes sense. My complicated system has always worked fairly well! Best wishes nick
link to this comment |
C
Chris.SE4:06 PM
Nick :
Hi Nick, thanks for the reply. That sounds like a great setup, and no doubt I shall have to watch my Ps & Qs to make sure I'm not telling granny how to suck eggs :D
Three things really just to mention.
Watch the 100% signal. I'm sure you are capable, but better to measure the signals strength that's actually going to the tuner input and make sure it's not too high as overloaded front ends (as I'm sure you know) can cause identical problem as too weak a signal or loads of interference.
Some sets/boxes will still show 100% even if it were say eg.120%, others will sometimes show a misleading reduction in the strength figure so eg. could shown 80% when in fact it could be 140% plucking a number out of the air! It all depends on where it's actually being measured in the set and what the AGC is doing (as I'm sure you realise).
With the Planned Engineering work, depending on what they are doing (they never give us the detail), if for example they are using the reserve antenna for any of the multiplexes, the signal reaching you could be much lower (because of the terrain) than operating on reduced power. Then that combined with any significant Tropo or even a bit of simple temperature inversion (which could occur more easily) might make signals from Chalford (or anywhere else of course) more significant. Remember also that polarisation can change a bit on route depending on multiple factors, terrain etc. and aerials aren't perfect either - even home brew ;)
Ridge Hill is no longer listed for Planned Engineering, so the work should be complete (for now!), but I've found the listings inaccurate on occasion :(
Make sure your filtering is taking out any 700MHz Mobile mast stuff (often inaccurately referred to as 5G as it could also be 4G depending on operator and location). One would expect such 700MHz interference to have greatest impact on the higher channels esp. C48, however I've seen a few odd cases where it seems to have had a more marked effect on channels as low as C24/C25 etc. so I now take nothing for granted.
Your filtering may already block 700MHz, but if not and you don't want to build your own, as already mentioned you can get a free one from restoretv.uk
All the best.
link to this comment |
S
Steve Donaldson10:08 PM
Nick : I have made further observations in respect of the Chalford relay.
At 700MHz Clearance, on 5 June 2019, the Chalford relay doubled ERP from 25W to 50W. At the same time, the positive offset on C21 (PSB3) was removed. All three channels, 21 (PSB3), 24 (PSB1) and 27 (PSB2), currently have no offset. At the same time, the ERP of Chalford Vale transmitter increased from 3W to 5W. I guess these power increases occurred to improve coverage rather than to counter possible CCI.
Ridge Hill has positive offset on C21 (COM4), while C24 (COM5) and C27 (COM6) are centre-channel. There was no change there. It has been like this since switchover.
If a receiver is presented with another, weaker signal co-channel with the wanted one, will one having offset and the other not (or one having positive offset and the other negative offset) mean that it will have more difficulty making sense of the signal than were they both to have the same offset, or both be centre channel? Does the fact that they aren't exactly overlayed potentially present more difficulty interpreting the signal?
The same question may be asked for signal mode, and in terms of DVB-T with DVB-T2 interferer and vice versa.
Why do some transmitters have offsets and some don't? What is the purpose of them?
If Chalford is a source of interference here, then it may be visible on the spectrum analyser below the frequency of the C21+ signal of Ridge Hill. The Ridge Hill C21+ signal is +0.167MHz with respect to Chalford's C21.
link to this comment |
Tuesday, 24 October 2023
Thanks Chris and Steve, Overload I'm sure is not a problem Chris, I can insert various attenuators until COM5 and COM6 start to degrade in strength and quality. Strange yesterday evening COM4 was 100% strength and 0% quality. So I'm coming round to the idea that the signal is being corrupted by possibly Chalford after all. That doesn't explain why its got so bad recently, but there may be many factors involved. 4G is well notched in my little box and not that strong in the first place.
Steve I can't see Chalford on the spectrum analyzer with Ridge Hill present, anyway digital signals just appear as blocks of noise.
But today just for a laugh I connected the group B vertical aerial (Stroud relay) to the spectrum analyzer and could clearly see the 3 multiplexes from Chalford. I know it was Chalford because the PSB channels from Ridge Hill were not present. But when I checked on the TV diagnostic none of these multiplexes were giving any strength or quality, but could still be capable of interfering. BTW COM 6 (27) was 100% 100% signal and quality, don't often see that.
Anyway as I said I'm not too bothered, just like playing around with this stuff. Often find setting up a system like mine is more interesting than actually using it!
Thanks again both, Nick
link to this comment |
C
Chris.SE1:53 PM
Nick:
I know where you are coming from Nick, I wish I had a bit more time to do things like that myself but have to do many more normal shall I say general chores. One day :D
Chats/Discussions like this are far more interesting than the usual faults people have ;)
link to this comment |
S
Steve Donaldson2:27 PM
Nick: The bandwidth the signals of Ridge Hill C21+ and Chalford C21 are not exactly overlayed, one on top of the other. I was wondering whether might be visible on the spectrum analyser.
The bandwidth of a DVB broadcast is 8MHz. The centre of channel 21 is 474MHz. Thus, a signal centred on the channel (as with Chalford) will begin at 470.000MHz and end at 478.000MHz.
The Ridge Hill C21+ has positive offset of 0.167MHz, hence it starts at 470.167MHz and ends at 478.167MHz.
I wondered whether the Chalford signal was visible between 470.000MHz and 470.167MHz.
In addition to the questions I posed in my previous comment, questioning the reason for offsets, will a C21+ signal not interfere with one on C22? Presumably it will, hence why Ridge Hill C22 (PSB3) also has a positive offset.
Another question is: could it be that the positive offset of Ridge Hill is the problem? What if Ridge Hill had been negative offset and Chalford centre, or Ridge Hill centre and Chalford positive offset (i.e. Ridge Hill comes first in order of ascending frequency)? Might the situation have been different in terms of the receiver being able to make sense of the Ridge Hill signal, even in the presence of the Chalford one?
Or, has the offset got nothing to do with it and it just so happens that the ratio of the strength of interfering Chalford to the wanted Ridge Hill at the receiving aerial is greater for C21/C21+ than for C24 and C27? Or is it to do with the fact that Chalford C21 is DVB-T2?
link to this comment |
Wednesday, 25 October 2023
N
Nick 2:04 PM
It's very hard with digital signals to distinguish one multiplex from one transmitter to another, they just appear as blocks of 'noise' on the spectrum analyzer, was much easier in the days of analogue TV. These days you'd need more sophisticated equipment than I have to do proper diagnostics, so I don't have any answer to your questions Steve. Channel 22 is absolutely rock solid BTW as are all the PSB multiplexes.
Anyway thanks both
link to this comment |
Thursday, 26 October 2023
S
Steve Donaldson12:51 PM
Nick : I know, you've gone much deeper into it than most viewers.
If you refer to the Chalford page on this website you will see the radiation pattern for it. There are two lobes, one roughly east north east, which gets the full 50W, and; the other is roughly west north west which is narrower and 9dB down, and which is pointing in your direction.
Chalford is on a bearing of 307deg out from your road.
link to this comment |
Select more comments
Your comment please