GB3YT testcards/audio

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GaryM1EGI
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GB3YT testcards/audio

Post by GaryM1EGI » Sat Aug 29, 2015 11:34 am

Having now received GB3YT, I was wondering what you guys use to play out the test cards and the synthesised speech?

The reason I ask is the media player I have been given for the GB3TT rebuild can only playback one type of media at a time, also once power is removed it requires interaction via remote control to set it back to image playback mode - so not much use after a power cut!

73's Gary (M1EGI)

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G8NZR
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Re: GB3YT testcards/audio

Post by G8NZR » Tue Sep 01, 2015 7:56 pm

Hi Gary

The test cards and speech are created with windows and then converted into a VOB file (same as a DVD) and then played via a mini media player. The player is set to auto play on power up and repeat the file when finished. This is a fairly easy way of creating the effect you are seeing on YT, and easily changed by just swapping the memory card if needed. The ones we have used are called 'NBOX', but there are other variants on places like ebay etc. I suppose you could also burn the VOB file to DVD and use an auto repeat DVD player!

We have had planned power cuts on site (due to planned upgrade work on the electric supplies), and on all occasions they have succesfully re-started without any intervention. The audio needs reducing slightly on our next visit to site - it's just set a bit on the high side.

Hope this info helps.

73s Kay
G8NZR

GaryM1EGI
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Re: GB3YT testcards/audio

Post by GaryM1EGI » Fri Sep 04, 2015 10:02 pm

Hi Kay,

Thanks for the update.
I will pass the details on to Steve the repeater keeper for GB3TT as I want to make the repeater as easy as possible to set-up and run & at the moment is JPG test cards and ID would come from the logic card.
BUT this requires to power up the media player via remote control and select image play back, there is no auto mode I can find.

Isn't there a requirement to have ident as morse?

I am hoping to try receive YT from here (IO93gl) but I think a pre-amp will be required and maybe getting the antenna above roof height, this will be with the new BATC RX so even without a live image or lock I should be able to peak the antenna and I hope to see signs of YT.

73's Gary (M1EGI)

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G8NZR
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Re: GB3YT testcards/audio

Post by G8NZR » Sat Sep 05, 2015 7:33 am

Hi Gary

Just a quick response... I'm not aware of any legal requirement to have a morse ident when in standby. There is a low level morse ident every five minutes when the repeater is in use so as not to obliterate any conversation taking place. The standby transmission is both audibly and visually identified as required by the license.

Being digital, the signal is either received or not (as opposed to an analogue signal being noisy and barely readable), so the use of morse ID to punch through the noise is really not required on weak digital signals.

73s Kay
G8NZR

G1LPS Terry
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Re: GB3YT testcards/audio

Post by G1LPS Terry » Mon Sep 07, 2015 2:45 pm

Hi Kay

Well done to you both for getting the repeater on air and so quickly (I know the financial and time costs involved )
I saw some nice pictures received by G4EWJ Brian and F6DZP Jean-Pierre on there way to CAT15 BATC at the weekend. :D

I was interested on this discussion as we are thinking of updating redesigning our logic etc soon.

In the guidance I received when building GB3KM (Which was quite a thick document) there is a requirement to identify in morse whether in beacon standby mode or use.
A quick look on the ETCC gave this document. http://www.ukrepeater.net/documents/voi ... ements.pdf
Which says that an additional NOV is needed for speech announcements. They can be digital or analogue.
The announcements shall not in any way replace the requirement for the unit to identify in Morse Code at the specified period and in the form required within the main NoV and in accordance with the requirements laid down in BR68.

Some what dated these days and could do with a review. As you say with DATV you either receive it or you don't. ID is in-bedded in the TS.
You don't even need it to tune the audio carrier as that's in the TS (PID).
No two ATV repeaters are alike logic wise.

I,ve looked for YT from home here in County Durham Kay USING 4 X 44 element Yagis but cant see it .
I'm planning to take a trip to Sutton Bank area to look for it when next visiting relatives that way.
Is the RX giving good performance now? The Tx is certainly as I know of a few that have received at distance now.
Is there any time that you both are active or monitoring the repeater?

Well done again.

Kind Regards
Terry G1LPS

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G8NZR
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Re: GB3YT testcards/audio

Post by G8NZR » Tue Sep 08, 2015 5:52 pm

Hi Terry

Nice pictures on the BATC website given in your link :D. To cover your other points...

In theory, the receiver should be reasonably sensitive, but the lack of a calibrated DVB-S signal generator means we can't fully verify what the sensitivity actually is at the moment. The original de-sensing problem seems to have been solved due to piece of faulty coax. Graham and myself are planning to have a drive around over the next few days and see how it performs in the local area. I will post results in the froum news section.

I never received much guidance in the form of booklets etc when building up YT. The ETCC document you mention is very much out of date and also only a draft copy for information only. Just to be on the safe side, I emailed Noel G8GTZ and put the question to him - looks like its not actually the first time he's been asked this. He subsequently checked with the ETCC as to the current position and this is his reply;

"For clarification Ofcom no longer require mandatory ID in morse, identification may be made in the mode that the repeater is using so that digital repeaters may identify in their bit stream and so on."

For the Digital ATV repeaters, this would mean a mandatory callsign insertion in the DVB-S service information tables, and then optional audio/video ident at the discretion of the NOV holder.

YT logic wise - it was all designed and built by myself - not very complex and may in future have to be updated to one of the commercial units that are available. Currently it serves its needs and operates just as a simplex audio repeater would work. Its all triggered by the alarm/lock output of the Tandberg receiver.

73s, Kay
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G1LPS Terry
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Re: GB3YT testcards/audio

Post by G1LPS Terry » Wed Sep 09, 2015 8:58 pm

that is good news
Terry

GaryM1EGI
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Re: GB3YT testcards/audio

Post by GaryM1EGI » Thu Mar 17, 2016 8:58 pm

G8NZR wrote:
> Hi Gary
>
> The ones we have
> used are called 'NBOX', but there are other variants on places like ebay
> etc. I suppose you could also burn the VOB file to DVD and use an auto
> repeat DVD player!

Hi Kay, just wondering if you know the model number for the NBOX?

I bought one which does auto play, but doesn't seem to support VOB files or a wide range of other formats for that matter...
Progress with GB3TT is going well and should be ready to go back on air in beacon mode in the next few weeks I hope!

73's Gary (M1EGI)

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G8NZR
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Re: GB3YT testcards/audio

Post by G8NZR » Fri Mar 18, 2016 6:30 am

Hi Gary

Since I replied, there are other items called NBOX that seem to have appeared. The one we use does not have a model number or label on it, but looks like the picture below. This plays most kinds of media as my previous post. It also comes with remote control which is used to set 'Repeat all' and output volume level which is useful for setting audio TX levels. On the other side of the box (out of view in the picture) is a USB connector which can be used with a standard USB stick as well.

Good luck with TT and hopefully I may be able to receive it from home.

[attachment=0]nbox media player.jpg[/attachment]

73 Kay
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GaryM1EGI
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Re: GB3YT testcards/audio

Post by GaryM1EGI » Sat Apr 02, 2016 10:04 pm

Hi Kay.

Thanks for the picture, this looks exactly the same as the unit I bought for TT.

The comtech modules should be with me this week which are now repeater hardened and set for correct deviation with pre-emphasis and de-emphasis.
I have created a nice sequence of ID audio and test cards for the beacon phase of getting the repeater back on air, but I am struggling to get the file format compatible with the player!

Next week or so I hope that TT starts to send out a signal again, it turns out the PA I was given to work with has no output so I am loaning the repeater one of mine for now.
Fingers crossed interest will be generated once on air and donations might start to come forward.

Gary (M1EGI)

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