Internet connected only repeaters

Ideas, technical topics, help and discussion for ATV repeater builders
g8gtz
Posts: 920
Joined: Wed Apr 07, 2010 6:26 pm

Internet connected only repeaters

Post by g8gtz » Fri Feb 03, 2017 10:00 am

Mike G0MJW said in a separate topic - http://www.batc.org.uk/forum/viewtopic. ... 827#p11739
The problem with a repeater is the license takes ages and not to mention all the other work. So, how about a network of web connected receivers that stream to the BATC streamer?
I have checked with the RSGB ETCC committee and we can see absolutely no reason why this cannot be done to encourage activity where there is no repeater or an NoV is delayed - it is no different to all the web SDRs which are now available.

In fact, the GB3HV group did exactly this for over 3 years whilst we waited for the NoV and there are already 2 similar systems on BATC.TV - one from Enfield in North London and the G8LES link system.

So if you are thinking of putting a repeater on air and want to do long term tests or if you are waiting for an NoV, we would be happy to put up a channel in the repeater section on BATC.TV. As these systems will not be able to use an allocated callsign, I suggest a system where we use the postcode of the site as an identifier.

These could be very simple units - particularly as we now have the Portsdown unit to stream to batc.tv you don't even need a PC.

Thoughts?

Noel

M5TXJ
Posts: 131
Joined: Wed Jul 05, 2017 8:34 pm

Re: Internet connected only repeaters

Post by M5TXJ » Sat Dec 16, 2017 3:53 pm

Hi Noel

I'm very interested in the possibilities of this but as usual have several questions...

I understand that a Pi running Portsdown software and an Easycap can be used to provide a stream to the Internet but that requires a video input. We have 3 Portsdown builders in this area (myself included) and no analogue, so a digital receiver would be essential. Would you recommend a Freesat receiver and Alford slot (with preamp) as the easiest way to go about this or something completely different? If a Freesat rx is there one recommended that will power up on a selected frequency if power fails?

73 Dave.

g8gtz
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Joined: Wed Apr 07, 2010 6:26 pm

Re: Internet connected only repeaters

Post by g8gtz » Mon Jan 01, 2018 10:18 am

Hi Dave,

Looks like I missed this post but answered it on another thread.

If you are looking for a low power logic / switching system for a simple ATV repeater it may be worth taking a look at the RPi based kits produced Dave G8PUO (GB3JT keeper). I'll say it before Dave GKQ does, it can't be run on the same RPi as a Portsdown streamer but could make a neat system based on 2 RPis.

https://hamkit.co.uk/product/hamkit-vmac-pihat-built/

73 Noel

M5TXJ
Posts: 131
Joined: Wed Jul 05, 2017 8:34 pm

Re: Internet connected only repeaters

Post by M5TXJ » Mon Jan 01, 2018 1:52 pm

Now bookmarked, that certainly looks handy if we ever get to full repeater status.

Thanks.

Mike-G8DLX
Posts: 5
Joined: Sat Dec 02, 2017 8:12 am

Re: Internet connected only repeaters

Post by Mike-G8DLX » Fri Jul 06, 2018 7:28 am

Hi

Following discussions with another local amateur we are considering the possibility of setting up a streaming receiver. Looking at the various CQ-TV magazines and BATC Wiki site it looks as if the setup would be:-

A Mini-Tiouner with associated PC feeding an EasyCap video capture device into a Pi 3 loaded with the Portsdown software and then into the internet. As we would not be transmitting the rest of the Portsdown boards would not be needed and I see we would not need the touch screen on the Pi.

This looks a fairly simple setup, am I missing something? Any comments or advice on this would be welcome.

Due to limited internet data available on site we would need to limit the streaming to times a signal is being received and there may be other timing limitations but we feel the setup would be useful for testing transmit equipment and paths. Options would include using either 70cm or 23cm.

Thanks
Mike – G8DLX

g8gtz
Posts: 920
Joined: Wed Apr 07, 2010 6:26 pm

Re: Internet connected only repeaters

Post by g8gtz » Fri Jul 06, 2018 7:53 am

Hi Mike

Sounds about right - a couple of comments:

Suggest you use a big wheel or Turnstile on 70cms - I've just put some info on the wiki https://wiki.batc.org.uk/Technical_topi ... ders#70cms

You will need a pre-amp (PGA103 or similar) plus a good tight filter https://wiki.batc.org.uk/70cms_filters as there is a lot of other rubbish on 70cms.

To switch the streaming you can use the Portsdown (BTW you are correct, you just need the Rpi and s/w) in keyed streaming mode https://wiki.batc.org.uk/Streaming_to_b ... spberry_Pi

This can be driven by the detector circuit on MiniTiouner shown at the bottom of this page https://wiki.batc.org.uk/Minitiouner_Hardware

73
Noel - G8GTZ

g8gtz
Posts: 920
Joined: Wed Apr 07, 2010 6:26 pm

Re: Internet connected only repeaters

Post by g8gtz » Fri Jul 06, 2018 8:02 am

Mike,

Were you aware that we have just got a 3.4GHz repeater licensed for Edge Hill which should give good coverage in your area - I'm currently building the transmitter for it and I know the group would welcome any support you could give.

Also Peter G8DKC has just applied to move GB3GQ from it's temporary site up to a new site near J22 on the M1 which should also cover your area.

https://www.ukrepeater.net/tvrepeaterlist.htm

73
Noel

g0mjw
Posts: 502
Joined: Sat Sep 20, 2014 9:15 am

Re: Internet connected only repeaters

Post by g0mjw » Fri Jul 06, 2018 8:19 am

Hi Noel,

Why can't the TS Valid line be used? Seems easier than sending and detecting 22kHz? On my protoype minitiouner V2 I just linked an LED to the requisite pins on the TTL chip and it works as a lock detector.

Mike

g8gtz
Posts: 920
Joined: Wed Apr 07, 2010 6:26 pm

Re: Internet connected only repeaters

Post by g8gtz » Fri Jul 06, 2018 9:17 am

It can and sounds a better idea but it's not documented anywhere (ideally on the wiki) so no-one including me knows about it!

Noel

g0mjw
Posts: 502
Joined: Sat Sep 20, 2014 9:15 am

Re: Internet connected only repeaters

Post by g0mjw » Fri Jul 06, 2018 11:05 am

g8gtz wrote:
Fri Jul 06, 2018 9:17 am
It can and sounds a better idea but it's not documented anywhere (ideally on the wiki) so no-one including me knows about it!

Noel
OK - I did mention it a while back in the lock lights thread, viewtopic.php?f=15&t=4489&hilit=lock+lights

My lock indicator was a blue LED. Blue LEDs make useful logic line status indicators when connected between ground (or VCC) and logic pins via 1.3k resistors. Blue LEDs will only light above about 2.5V. The current will be low enough due to the 1.3k resistor and the LED threshold to not fry the gate. (OK, probably not fry the gate). As the LED threshold is 2.5V, this will still be seen as a logic high in following gates even if the LED drags down the volts. This is of course just for testing, the logic lines should always be properly buffered rather than have LEDs stuck to them. None of us ever hack signals like this.

I would recommend reading the SERIT FTS-4335 data sheet before doing any modifications. There is a lot of information in there, including descriptions of each pin function (and for Yorkshire ex-pats, even which pin is which)

I found the most useful control lines to monitor for status indicators are TS_VALID and TS_ERROR. It depends which NIM you have but for the SERIT these are found on pins 15, 17, 35 and 37. The lower numbers are for TS1, the higher for TS2. The BATC V2 board uses TS2, so TS2-VALID is pin 35 and TS2_ERROR is pin 37.

TS_VALID indicates when there is a valid transport stream. An LED connected to the TS_VALID signal is effectively a lock light and buffering the TS_VALID signal would perhaps be useful to control a stream or repeater.

TS_ERROR goes high if the TS error rate is too high. It doesn’t go high until a TS is detected and then errors, but unfortunately it will then stay high even if the signal disappears, which makes it less useful. I have not quite figured out how to use that logic yet. Perhaps it is useful in a repeater as a quality indicator to show where the signal is dropping in and out.

Buffering logic signals is beyond the scope of this, but some ideas are here http://hyperphysics.phy-astr.gsu.edu/hb ... uffer.html


Mike

Edit - presumably this could also apply to other receivers using NIMs.

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