Sutton Coldfield multiplex query

[Joe_90]

Just helping out on a query on another thread http://www.world-of-satellite.com/showthread.php?39109-which-Transmitter
Looked at the terrestrial_freeview_GB.xml file and it seems to have this entry associated with the Sutton Coldfield transmitter:
<configuration key="sutton_coldfield" frequency="626000000" inversion="0" modulation="4" system="1" bandwidth="8000000" code_rate_hp="5" code_rate_lp="5" transmission_mode="6" guard_interval="5" hierarchy="4">Sutton Coldfield</configuration>
I understood that this file was intended to reference the SD BBCA multiplex on each main transmitter. According to ukfree.tv, the BBCA multiplex on this transmitter is C43 (650MHz), not C40+(626MHz) as in the xml - this is the BBCB HD multiplex. Am I mistaken in my understanding of this file?

[abu baniaz]

The simple answer is that the values in that xml are what ABM is meant to tune to in order to get the other channel details. As was discovered in someone's case not all the data is shared between the main transmitters/repeaters. Unfortunately ABM won't scan several frequnecies and then merge the details. The 11 HD channels I get cannot be added by ABM. I had to scan a few times to provide the logs for Peter.

If the local tansmitter details are incorrect for ABM, then we should amend them. Not sure how we determine which is correct. But there must be reception.
The transmitter frequencies for sutton coldfield should be added to the terrestrial.xml for conventional scanning usage.

In my case ABM has the following details for Crystal Palace:


<configuration key="crystal_palace" frequency="546000000" inversion="0" modulation="4" system="1" bandwidth="8000000" code_rate_hp="5" code_rate_lp="5" transmission_mode="6" guard_interval="5" hierarchy="4">Crystal Palace</configuration>

Although that is the HD mux (I think), no HD channels are pulled in by ABM. Conventional scan pulls in 11 HD ones (I chose complete scan. Network scan being off or on made no difference. 138 channels received).

I'm sure Andy/Peter will enlighten us.

Is there an way to get the frequencies from ukfree in a tabulated format?

[Joe_90]

Mux PSB1 (BBCA) is always the primary SD multiplex on any main transmitter, which is what Andy was looking for, I think. I understand that DVB-T scanning in ABM should work reliably for SD (DVB-T), but I understand that there are issues with HD (DVB-T2). Again, Andy may be able to enlighten. I understand that ABM cannot merge info from different frequencies on the provider entries (tried that for the Irish Saorview system - but no go). However, in the case of Sutton Coldfield, the primary frequency in the table points to the HD multiplex instead of the SD multiplex, which is wrong from two perspectives.
1) a user with a DVB-T tuner cannot even decode the modulation, so it's useless to him
2) a user with a DVB-T2 tuner can decode the signal but ABM apparently can't follow the links or add the HD channels for various reasons.

A complete scan, as you say, will result in all available channels being stored, but then you don't have the nice bouquet arrangement provided by ABM in the satellite environment.

If someone is scanning the primary transmitters to provide logs etc. to Peterj (which I have done for local Saorview) then they need to use a DVB-T tuner, not a DVB-T2 else they run the risk of finding an HD multiplex for BBC as you seem to have for Crystal Palace.

The answer, for the moment, for the poster in the other thread, is to have all the multiplexes (transponders) for Sutton Coldfield added to the standard "teerstrial.xml" file and his DVB-T tuner will ignore the DVB-T2 HD muxes and only add the SD ones. Alternatively, he can run a complete scan having set his tuner to DVB-T Europe, or manually scan for the specifc channels in his area. If Sutton Coldfield is set to 650MHz and the proper modulation in the ABM xml file, then the ABM search will probably work ok for SD.

I can't really help with scanning Freeview as I am "geographically compromised", but I could do a bit of desk checking on the ABM xml file if you like to cross verify the frequencies. The issue I have with the ABM xml file is that there new values for modulation, system, transmission_mode which are not documented in the file, unlike in the standard "terrestrial.xml".

[abu baniaz]

Would you be so kind to post the T1 details for Crystal Palace.

[Joe_90]

Would you be so kind to post the T1 details for Crystal Palace.
Hi abu - had just looked up Crystal Palace. The PSB1 (BBCA) mux is C23 UHF which is 490MHz (490000000). The mode is 64QAM 8K 2/3, but I don't know how to translate that into the other settings in the xml file, but if Peterj or Andy would enlighten, perhaps? Because you scanned the HD multiplex the other settings will need to be changed as they differ between DVB-T/T2