All posts by John
Below are all of John's postings, with the most recent are at the bottom of the page.
Hi Chris SE
On Oct 23 two signals from EM disappeared CH56 was moved to 39 not 37 and the other one CH?? moved to 37. Are you sure 56 is still there because I believe it is released to 5G? This is the EM map I ended up with:
CH MUX Operator
32 COM7 HD ARQC
37 COM8 HD -
39 Local -
41 PSB3 BBC B HD
44 PSB2 D3&4
47 PSB1 BBC A
48 COM6 ARQ B
51 COM4 SDN
52 COM5 ARQ A
My next door neighbour has a chimney aerial pointing to EM and I have measured the signal at ground level to be about 56dBuV, most likely higher on the chimney. I agree EM should be my desirable transmitter but the house is located just below the line of site horizon. We are about 200m above sea level whereas Bilsdale is 600m so there is a very strong signal from there. Its all down to the topology.
As for the loft aerial its a personal choice plus its maintenance free and storm proof. The 84 and 69 measurements are inside the house at the TV points and are values are after amplification. The varying quality on arises from the EM aerial. What I did notice is that the Optima L20F has been replaced by a L20FK which suggests that the final map will see all channels above 48 released to 5G.
The Vision amp says its input should not exceed 70dBuV so I'm well inside of this but clipping may be taking place so I can't rule this out. The mapping is all over the place at the moment a proper mess and I don't think the Freeview team are properly clued up I know because I rang them on the day. Looks like I'm in for some more fun to come next week. This is the current Bilsdale map being used. I added EM 39 to get LCN CH7, Leeds TV.
CH MUX Operator
23 PSB3 BBCB HD Bilsdale
29 PSB2 D3+4 Bilsdale
31 COM7 HD - Bilsdale
37 COM8 HD - Bilsdale
39 COM8 HD - Emley Moor
40 COM6 ArqB Bilsdale
43 COM4 SDN Bilsdale
46 COM5 ArqA Bilsdale
47 PSB1 BBCA Emley Moor
I mentioned using two aerials: a Group W and a Group B. The aerial signals were combined using a Mersat BZT G687 658D 2 way splitter multiplexer. Because this is a passive device and the power pass leg is not used inputs and outputs can be transposed meaning that the single input demultiplexes to two outputs. The aerials were connected to the two outputs and the input was connected to the Vision amp input. Its output feeds signal to the house distribution amp and which receives 5v to power it.
The reason why TV auto tuning didn't work is down to the numeric order of MUX channels. TV auto tuning begins with CH21. BBCA is on EM CH47 but 'interference' from Bilsdale BBCA CH26 means that the TV database on a first come first serve basis registers BBC One Newcastle. CH47 is then ignored as a duplicate channel. A similar thing happens with EM BBCB on CH41, Bilsdale BBCB is on CH23 so CH 41 is ignored as a duplicate channel. Not much is said on this medium about what actual channels should be used for manual tuning it would be helpful when cross channel interference is a problem.
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Hi Chris
The graphic seems to confirm that EM CH56 is gone. I went around to measure my neighbours signal strength at the back of their TVs which is about 45 dBuV but only because they have tapped off parallel connections from the main down feed into three or more rooms. Need I say more?
I went to trouble of mapping the LCN landscape one aerial at a time. The process was disconnect the TV aerial and auto tune to clear the TV database. Then to reconnect the aerial and manually retune one MUX CH at a time for CH21-69. The results were:
LCN Mappings from Channel listings | Freeview
Aerial XMIT MUX CH dBuV TV SS/SQ LCN
GRP B BILS BBCB 23 58 100/100 101 102 103 104 105 204
GRP B BILS BBCA 26 72 100/100 1 2 9 201 202 231
GRP B BILS D3+4 29 61 100/100 3 4 5 6 10 13
GRP B BILS COM7HD 31 60 100/100 57 67 74 78 86 92
GRP B EM COM7HD 32 70 100/100 57 67 74 78 86 92
GRP B EM Local 39 58 100/100 7 48 50 60 207 -
GRP B BILS ARQB 40 61 100/100 22 25 29 31 35 36
GRP B EM BBCB 41 70 100/39 101 102 103 104 105 204
GRP B BILS SDN 43 61 100/100 12 16 20 21 26 27
GRP B EM D3+4 44 70 100/100 3 4 5 6 10 13
GRP B BILS ARQA 46 62 100/100 11 17 19 23 28 32
GRP B EM BBCA 47 75 100/100 1 2 9 201 202 231
GRP B EM ARQB 48 71 100/100 22 25 29 31 35 36
GRP B EM SDN 51 70 100/100 12 16 20 21 26 27
GRP B EM ARQA 52 72 100/100 11 17 19 23 28 32
Quite a lot of duplication with the Group B aerial's poor forward/back rejection losing only about 10dBuV. The mapping for the Group W log periodic was a lot cleaner with only one duplicate because of high forward/back rejection:
Aerial XMIT MUX CH dBuV TV SS/SQ LCN
GRP W ? D3&4 22 69 100/100 3 4 5 6 10 13
GRP W BILS BBCB 23 80 100/100 101 4 5 6 10 13
GRP W BILS BBCA 26 82 100/100 1 102 103 104 105 204
GRP W BILS D3&4 29 81 100/100 3 2 9 201 202 231
GRP W BILS COM7HD 31 77 100/100 57 4 5 6 10 13
GRP W BILS COM8HD 37 77 100/100 56 67 74 78 86 92
GRP W BILS ARQB 40 78 100/100 22 64 83 91 93 96
GRP W BILS ARQA 46 79 100/100 11 25 29 31 35 36
I seem to be picking up a CH22 signal that duplicates CH29 and I don't know why or where its coming from, presumably from Bilsdale?
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Hi Chris
I agree the missing TV signal on EM CH56 is likely down a lack of gain on the Group B aerial however, on the 23rd the Group W aerial was pointing at EM when CH56 disappeared. I swapped them around later on. On the EM LCN mapping I noticed COM8HD LCN 56,67,74,78,86,92 are missing. As I'm using COM8 on BILS CH39 its not a problem. So I guess EM COM8 is still there but I'm not in a position to see TV pictures from it. I'll get back to you on this but for the moment I'm more than happy with my two aerial solution.
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J
Bilsdale (North Yorkshire, England) Full Freeview transmitterWednesday 13 November 2019 1:34PM
Bradford
Bilsdale Manual Tuning Map 13-Nov-2019
It appears CH37 COM8HD has gone?
CH MUX LCN
21 BBCA 1, 2, 9, 201 ---------- Was CH26
24 D3&4 3, 4, 13, 18 ---------- Was CH29
27 BBCB 101, 102, 103, 104 ---------- Was CH23
32 COM7HD 57, 67, 78, 92 ---------- Was CH31
40 ARQB 29, 25, 31, 37
43 SDN 12, 20, 21, 27
46 ARQA 11, 17, 19, 28
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Hi Chris
> Don't forget that there's a good chance you'll lose COM8 from Bilsdale on the 13th when it moves
> to UHF56 according to the predicted reception, and COM7 moving to 55 is predicted to get flakey.
As of today 13-Nov-2019 COM8HD has gone from Bilsdale.
Bilsdale - Optima L20F Group W
CH MUX LCN
21 BBCA 1, 2, 9, 201
24 D3&4 3, 4, 13, 18
27 BBCB 101, 102, 103, 104
32 COM7HD 57, 67, 78, 92
40 ARQB 29, 25, 31, 37
43 SDN 12, 20, 21, 27
46 ARQA 11, 17, 19, 28
TV reporting of LCN is not in numeric order so I'm using LCN from:
Channel listings | Freeview
TVs not picking up any TV signal on Bilsdale MUX CH55,56?
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Hi Chris
> As just mentioned on the Bilsdale page, the COM7 you have there is Emley Moor.
> As predicted you aren't getting C55 & C56 from Bilsdale, signal too poor.
Strange? I'm seeing two lots of COM7 with LCN 57, 67, 74, 78, 86, 92, 99, 107, 109, 110, 113, 733
on MUX CH32 and CH55. CH32 Signal Quality is a solid 100% which I assume is Bilsdale.
CH55 Signal Quality hovers between 19% and 50% so I'm assuming its Emley Moor. If that was
the case then I should see something on COM8 CH56 regardless of the Group K aerial but I'm seeing
nothing and have lost COM8 on both Bilsdale and Emley Moor. The problem is the TV signal condition
meter says COM78 for both CH. Is there anything else, something buried in the signal that might identify
the the transmitter?
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Monday 4 November 2019 3:57PM
Bradford
I live in Wibsey BD61LE and for this location my transmitter should be Bilsdale in the North East plus I have a self imposed handicap in that my aerial is in the loft and it points toward Emley Moor. The aerial is a log Optima L20F Group W and my DIGIAIR dB says it receives at about 45dBuV. This feeds into 5v dc pass thru amp a Vision 20-1127 with 27dB gain which in turn feeds a house distribution amp. House TVs were tuned using auto then selecting Yorkshire as the area which in hindsight was a bit naive.
The retune of Oct 23, 2019 meant that COM8 HD CH56 was changed to CH37 and this caused problems with low signal level and dropout. To cut a long story short I moved the Group W aerial to point to Bilsdale (56dBuV) and added an extra Group B (Blake CR10B) to point to Emley Moor (45dBuV) and resorted to manual tuning of TVs and PVRs. The new MUX channel map looks like this:
CH MUX Operator
23 PSB3 BBCB HD Bilsdale
29 PSB2 D3+4 Bilsdale
31 COM7 HD - Bilsdale
37 COM8 HD - Bilsdale
40 COM6 ArqB Bilsdale
43 COM4 SDN Bilsdale
46 COM5 ArqA Bilsdale
47 PSB1 BBCA Emley Moor
CH47 is used used only to receive BBC1 Yorks on TVs whilst PVR tuning relies entirely on Bilsdale. In these cases CH47 is changed to CH26 PSB1 BBCA Bilsdale. The signal strength at the TV CH26 is 84dBuV with CH47 lower at 69dBuV. TV reports signal strength 100% with varying quality for CH47. Not that I anticipate any problems, I will swap the Group W log aerial for a similar Group K one to avoid any 5G issues and only because I have easy access to the aerials.