This is sanctioned on an experimental only basis and AMSAT-DL reserve the right to move the WB beacon towards the band edge or implement DVB-S with a wider rolloff which would render the frequencies unsuitable for this purpose.
So another challenge but should be manageable and prove a useful facility although we do see the chat being the major tool for reports and contacts.
Noel - G8GTZ
Personally 12.5Khz FM might be a good idea generally in the NB section, but I understand the issues here.
Answers to your questions as follows:
If you read the statement it does not mention permitted or forbidden modes but we should use common sense.
This agreement applies to the WB transponder only and to ATV co-ordination only - it does not apply to the NB transponder or general communications.
Sometimes it is better to accept things (gifthorses) at face value and not ask too many questions - and perhaps not make too much noise about it, incase others spoil it for us....
Noel - G8GTZ
Meanwhile, as the sun passes behind the satellite and all line up, it's raining and the sun is nowhere to be seen.
The text is carefully agreed: "15dB above the noise floor as shown on the Goonhilly spectrum monitor".
Various modes were considered, but the aim is to make this a minimum equipment, minimum impact, usable talkback facility alongside DATV taking into account the effect of frequency drift etc. It will should enable more reactive experimentation and testing with DATV modes, as has already been happening using the text talkback.
Topic title set to: "ATV co-ordination on Es'hail-2"
Let's talk about coordination in general.
There should be system where TXers send TX parameters:
*) symbol rate
*) format: DVB-S; DVB-S2, DVB-T etc
*) encoding: MPEG2;MPEG4(H.264);H265 etc
*) TX power in Wats
*) TX antenna size/gain
*) Scheduled start and end of TX
An RXers (listeners) Report following to system:
*) Signal level (absolute or relative to beacon?)
*) RX antenna size
I see this "system" digital and internet based (something like chat).
But this chat is special and build with functionality what can be used for automatic or semiautomatic use by software. For example every user have program or web page who can assist in process. Program automatically can set Minitiouner parametrs, write into logbook etc.
And now regarding voice channel.
This is good idea. Thanks to AMSAT-DL to allow more experiments including voice on WB transponder. But it doesn't mean we need to setup and use it immediately. Better to think and use efficiency than just simply use something.
For voice channel there is no "history". You can not "scroll back" and see what happened if you missed something in voice channel.
Many RXers start to asp for parameters and TXer need to replay parameters many times.
*) narrow band
*) low power
*) voice quality
*) higher power
*) wider band
You really need to set goals and only then make decision regarding modulation. I vote for FM, because we need reliable voice contacts (in broadcast it is called "back channel") and not experiments with SSB or low power.
*) TX and RX information (including parameters) can be in chat.
*) Chat should be upgraded with one more "window"
*) When patrician send "Nickname StationTechInfo: some data" then data goes to second window and automation software can parse it to setup minitiouner software, log QSO etc.
*) When patrician send "Nickname whatever text goes there" then data goes to regular chat window.
*) System (server) keeps all TX and RX evens in some kind of online logbook database.