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Ok, so last year after moving from West Midlands to East Midlands (still on the Sutton Coldfield Transmitter), I posted a question about having lost the weaker multiplexes (Channel 4+1; BBC4 HD; 4seven HD etc). Graham Thompson helpfully pointed me at a Masthead Amplifier which brought them all back:
Now, the recent Freeview retune (did I miss an announcement somewhere?) has shifted these to Com7 & Com8 on less power (89kW unlike the 200kW the others are on). After retuning, they have come back but are only ‘hit & miss’, there one moment and giving a ‘no signal’ error the next.
Are there any other options (e.g. higher power Masthead amp?) that would work, if not would a better/modern aerial work (mine’s 20 years old/basic) do better or is even that uncertain?
I think you’ll need to update your aerial to a Wideband or Group T one. It’s also possible that Masthead amp may not be a wideband one, though that’s now quite rare.
SRF – 15 minutes ago »
I think you’ll need to update your aerial to a Wideband or Group T one. It’s also possible that Masthead amp may not be a wideband one, though that’s now quite rare.
I had an aerial change yesterday due to the COM7 & 8 debacle. The installers fitted a Log Periodic which should have sorted out the issue but I’m afraid it hasn’t worked.
I’m in Staffs Moorlands area so can either use Fenton or Sutton Coldfield. Installer tried both transmitters but it made no difference. All the other muxes are on good reception.
SRF – I believe it is wideband, but will check.
Faust – may I ask what the engineer charged for all this? And I take it the exercise was at your own risk, cost-wise?
And would anyone know if the Sutton Coldfield transmitter is at all likely to be power upgraded for these weaker Com7 & 8? I appreciate it’s a lot more power than many have, but this transmitter serves a massive area I believe.
No chance of a power increase on COM 7 and COM 8 the power is low to avoid adjacent transmitters causing co-channel interference. The plan is to move all COM 7 and COM 8 to the same UHF carriers in a Single Frequency Network (SFN).
https://en.wikipedia.org/wiki/Single-frequency_network
In order to achieve this the channel guard interval has to be raised which reduces the capacity. This is the reason for BBC 4 HD moving from COM 7 to COM 8.
COM 7 and COM 8 are due to close down in the next year or so as part of the 700MHz clearance.
Your best chance is a B or E group aerial (with a variable gain masthead amplifier if needed)
http://aerialsandtv.com/atvstockaerialtests.html#Bgroup
http://aerialsandtv.com/atvstockaerialtests.html#Egroup
The highest gain for the COM 7 and 8 frequencies is the XB16E but might be a bit large so the smaller DY14B may be the best compromise.
grahamthompson – thanks for the info. If COM7 & 8 are due to close down in the next year, what’s the plan for the channels like BBC4 HD etc they host? Are they likely to end up on a stronger Mux, which might solve the problem if I waited until then?
Roy22 – 4 minutes ago »
grahamthompson – thanks for the info. If COM7 & 8 are due to close down in the next year, what’s the plan for the channels like BBC4 HD etc they host? Are they likely to end up on a stronger Mux, which might solve the problem if I waited until then?
Freeview is pretty maxed out, so it would depend on changing the transmission mode from DVB-T to DVB-T2 and possibly encoding SD channels with H264/AVC rather than mpeg2. This would mean everyone will need Freeview-HD capable kit.
Do as I do have both Freesat+ and Freeview+ kit alongside each other, that covers pretty well all the bases
That’s something I’d consider, but it’s a bit complicated for now. Surely BBC4 HD etc will have to end up somewhere when Com7&8 go, presumably stronger?
There are plenty of dire minor Freeview channels that could be culled to make way for more major ones if so crowded.
Roy22 – 28 minutes ago »
That’s something I’d consider, but it’s a bit complicated for now. Surely BBC4 HD etc will have to end up somewhere when Com7&8 go, presumably stronger?
There are plenty of dire minor Freeview channels that could be culled to make way for more major ones if so crowded.
Channel 4 HD can be viewed using non freesat mode on a Freesat+ box and also recorded using a Foxsat-HDR.
Roy22 – 4 hours ago »
Faust – may I ask what the engineer charged for all this? And I take it the exercise was at your own risk, cost-wise?
£147.00 which included a new 4 way mast head splitter (which runs to 3 separate TVs). The old aerial was around 17 years old although the co-ax is much newer. Given it’s age and the fact it was a group A I thought it was time to replace it in any event. Log Periodic is a good aerial to have and will cover most bases – except it appears COM 7 and COM 8 on low power. 😥
At least I have Freesat to fall back on. The only channels I will really miss on Freeview is BBC4 HD and BBC News 24 HD.
I assume a relay transmitter simply replicates the same signal as the main transmitter for areas that don’t have line of sight or where the main tx signal is starting to fade off? The aerial from a main tx uses the horizontal plane whereas the relay uses vertical in order to avoid cross interference.
I suppose then that if I couldn’t receive COM 7 & 8 from Sutton Coldfield it was likely I would have the same issue off Fenton. Low power appears to be the issue.
Faust – 1 hour ago »
I assume a relay transmitter simply replicates the same signal as the main transmitter for areas that don’t have line of sight or where the main tx signal is starting to fade off? The aerial from a main tx uses the horizontal plane whereas the relay uses vertical in order to avoid cross interference.
I suppose then that if I couldn’t receive COM 7 & 8 from Sutton Coldfield it was likely I would have the same issue off Fenton. Low power appears to be the issue.
Relays don’t have COM 7 and 8 only some but not all main power transmitters have them. Fenton is a main power transmitter (underlined on linked map)
This shows Sutton Coldfield with it’s relays in purple and Fenton in pale blue.
Waltham relays are shown in Blue
https://www.ofcom.org.uk/__data/assets/pdf_file/0025/56383/central_v2.2.pdf
The aerial I linked to on ATV aerials will give you an extra 9dB lift on the com 7 and com 8 mux, which may be enough if it’s truly just lack of signal.
Faust – that’s quite a lot to pay without regaining Com7 & Com8, though I accept your reasoning that your old aerial was ageing anyway. I guess the installer made no promises when doing the work? I presume the Freeview retune must have given these firms a boost of work, and that equally they’ll pretty much know from your location what you’ll actually get from an upgrade?
I remain intrigued by where the channels hosted by this Mux pair will end up when they close (as Graham Thompson explained) and whether it is better to wait and see where we are in a year’s time.
grahamlthompson – 1 hour ago »
Faust – 1 hour ago »
I assume a relay transmitter simply replicates the same signal as the main transmitter for areas that don’t have line of sight or where the main tx signal is starting to fade off? The aerial from a main tx uses the horizontal plane whereas the relay uses vertical in order to avoid cross interference.
I suppose then that if I couldn’t receive COM 7 & 8 from Sutton Coldfield it was likely I would have the same issue off Fenton. Low power appears to be the issue.
Relays don’t have COM 7 and 8 only some but not all main power transmitters have them. Fenton is a main power transmitter (underlined on linked map)
This shows Sutton Coldfield with it’s relays in purple and Fenton in pale blue.
Waltham relays are shown in Blue
https://www.ofcom.org.uk/__data/assets/pdf_file/0025/56383/central_v2.2.pdf
The aerial I linked to on ATV aerials will give you an extra 9dB lift on the com 7 and com 8 mux, which may be enough if it’s truly just lack of signal.
We can use either Fenton or SC. Some of us are on Fenton some on SC. It appesrs to be down to which installer you choose as to which tx they select.
I posted a pic of the Log Periodic fitted in the other thread Graham. Even a powered booster wouldn’t pull in the new frequencies though. According to my neighbour this problem has been been mentioned on local radio, though didn’t hear it myself.
According to this link Fenton is classed as a relay and it’s aerial group is Vertical. https://www.a516digital.com/2018/03/freeview-frequency-changes-7th-march.html
Faust – 29 minutes ago »
grahamlthompson – 1 hour ago »
Faust – 1 hour ago »
I assume a relay transmitter simply replicates the same signal as the main transmitter for areas that don’t have line of sight or where the main tx signal is starting to fade off? The aerial from a main tx uses the horizontal plane whereas the relay uses vertical in order to avoid cross interference.
I suppose then that if I couldn’t receive COM 7 & 8 from Sutton Coldfield it was likely I would have the same issue off Fenton. Low power appears to be the issue.
Relays don’t have COM 7 and 8 only some but not all main power transmitters have them. Fenton is a main power transmitter (underlined on linked map)
This shows Sutton Coldfield with it’s relays in purple and Fenton in pale blue.
Waltham relays are shown in Blue
https://www.ofcom.org.uk/__data/assets/pdf_file/0025/56383/central_v2.2.pdf
The aerial I linked to on ATV aerials will give you an extra 9dB lift on the com 7 and com 8 mux, which may be enough if it’s truly just lack of signal.
We can use either Fenton or SC. Some of us are on Fenton some on SC. It appesrs to be down to which installer you choose as to which tx they select.
I posted a pic of the Log Periodic fitted in the other thread Graham. Even a powered booster wouldn’t pull in the new frequencies though. According to my neighbour this problem has been been mentioned on local radio, though didn’t hear it myself.
According to this link Fenton is classed as a relay and it’s aerial group is Vertical. https://www.a516digital.com/2018/03/freeview-frequency-changes-7th-march.html
It might be classed as a relay but having COM 7 and COM 8 is not normal, There are other mainpower transmitters that use Vertical (Check out Rowridge).
Lark Stoke which I use is also technically a relay but does not have COM 7 or COM 8.
Guessing both transmitters COM 7 and COM 8 now are part of a SFN like Lark Stoke is.
When two adjacent transmitters share the same frequencies in a SFN reception is all down the guard interval used and the ability of the aerial to reject the unwanted frequencies. Where I live the alternates using the same frequency are in completely different directions.
In this case it re-transmits the other MUX on a a different frequency isn’t the issue.
The fact that you have log 36 isn’t in doubt. In your location it’s clear that it’s going to be hard to discriminate between Sutton Coldfield and Fenton re COM 7 and 8.
I get virtually nothing from the other transmitters in the SFN (Bromsgrove and The Wrekin).
Suggest you contact OFCOM re the DTG results compared to your outcome.
There may be a cock up in the guard interval used re the SFN.
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