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.
grahamlthompson - 2 hours ago »
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.htmlIt 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.
According to what the installer told me, he along with other local installers are updating the authorities about the issue as customers are giving them earache after coughing up for a new aerial that's not solving the issue - understandable I suppose.
My local installer contacted me just before lunch to inform me he would be calling round just after lunch. When he arrived he said he'd had a call from a chap who was part of the transmitter group. The advice was where possible to switch over to the Sutton Coldfield transmitter.
Without more ado he put his ladders up, un-clipped the new aerial rotated it round a few degrees and turned the poles to horizontal (previously vertical). Re-tuned and result - I have now got COM 7 and COM 8. Signal strength is down at 55% mind you but quality is 100%.
Most of the other muxes are around 90% strength 100% quality with one notable exception. Channel 36 which Digital UK lists as 'Local' is only around 38% though again strength is 100%.
I didn't have this mux from Fenton. The channels are 7 Made in Birmingham, 68 truTV, 50 Sony Movie Channel +1 69 Sony Crime +1 207 Tiny Pop and 208 Pop Max. What does Local mean?
The frequencies now are as follows - 36, 39, 40, 42, 43, 45, 46, 55 and 56
My local installer contacted me just before lunch to inform me he would be calling round just after lunch. When he arrived he said he'd had a call from a chap who was part of the transmitter group. The advice was where possible to switch over to the Sutton Coldfield transmitter.
Without more ado he put his ladders up, un-clipped the new aerial rotated it round a few degrees and turned the poles to horizontal (previously vertical). Re-tuned and result - I have now got COM 7 and COM 8. Signal strength is down at 55% mind you but quality is 100%.
Most of the other muxes are around 90% strength 100% quality with one notable exception. Channel 36 which Digital UK lists as 'Local' is only around 38% though again strength is 100%.
I didn't have this mux from Fenton. The channels are 7 Made in Birmingham, 68 truTV, 50 Sony Movie Channel +1 69 Sony Crime +1 207 Tiny Pop and 208 Pop Max. What does Local mean?
The frequencies now are as follows - 36, 39, 40, 42, 43, 45, 46, 55 and 56
Faust - 2 minutes ago »
My local installer contacted me just before lunch to inform me he would be calling round just after lunch. When he arrived he said he'd had a call from a chap who was part of the transmitter group. The advice was where possible to switch over to the Sutton Coldfield transmitter.
Without more ado he put his ladders up, un-clipped the new aerial rotated it round a few degrees and turned the poles to horizontal (previously vertical). Re-tuned and result - I have now got COM 7 and COM 8. Signal strength is down at 55% mind you but quality is 100%.
Most of the other muxes are around 90% strength 100% quality with one notable exception. Channel 36 which Digital UK lists as 'Local' is only around 38% though again strength is 100%.
I didn't have this mux from Fenton. The channels are 7 Made in Birmingham, 68 truTV, 50 Sony Movie Channel +1 69 Sony Crime +1 207 Tiny Pop and 208 Pop Max. What does Local mean?
The frequencies now are as follows - 36, 39, 40, 42, 43, 45, 46, 55 and 56
Good news - Local is a very low power MUX transmitting local TV, you are lucky to get it as it's erp is only 10kW compared to COM 7/8 over 80kW.
The main mux use 200kW.
Around 60% strength is generally thought ideal so nothing to worry about at 55%. My loft mounted log 36 has the weakest MUX at 40% but still gives gives 100% quality and rock solid reception.
One of the advantages of a log is the excellent rejection of impulse interference so will work in noisy areas.
grahamlthompson - 45 minutes ago »
Faust - 2 minutes ago »
My local installer contacted me just before lunch to inform me he would be calling round just after lunch. When he arrived he said he'd had a call from a chap who was part of the transmitter group. The advice was where possible to switch over to the Sutton Coldfield transmitter.
Without more ado he put his ladders up, un-clipped the new aerial rotated it round a few degrees and turned the poles to horizontal (previously vertical). Re-tuned and result - I have now got COM 7 and COM 8. Signal strength is down at 55% mind you but quality is 100%.
Most of the other muxes are around 90% strength 100% quality with one notable exception. Channel 36 which Digital UK lists as 'Local' is only around 38% though again strength is 100%.
I didn't have this mux from Fenton. The channels are 7 Made in Birmingham, 68 truTV, 50 Sony Movie Channel +1 69 Sony Crime +1 207 Tiny Pop and 208 Pop Max. What does Local mean?
The frequencies now are as follows - 36, 39, 40, 42, 43, 45, 46, 55 and 56Good news - Local is a very low power MUX transmitting local TV, you are lucky to get it as it's erp is only 10kW compared to COM 7/8 over 80kW.
The main mux use 200kW.
Around 60% strength is generally thought ideal so nothing to worry about at 55%. My loft mounted log 36 has the weakest MUX at 40% but still gives gives 100% quality and rock solid reception.
One of the advantages of a log is the excellent rejection of impulse interference so will work in noisy areas.
Interesting info Graham thanks. Not a big surprise we can get the low power mux as the only entity higher than where we live is God. 
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