Talkback - how can we improve it?

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g8gtz
Posts: 1733
Joined: Wed Apr 07, 2010 6:26 pm

Talkback - how can we improve it?

Post by g8gtz » Tue May 11, 2021 8:31 am

I think it's time the ATV community looked at this again as when out portable we are often working distances beyond a simple .750 talkback system or is in the same band as talkback.

Whilst it may also be useful to have a national system that can be monitored in the shack, it needs to be useable portable so the specification needs to include:

Simple - not loads more gear to drag out when going portable.

Cost-effective - this is to be a tool to use and does not warrant spending £500+ on a brand new black box (that's against my religion anyway!).

Not reliant on a 4G mobile signal - because there are often not enough or too many!

Easy to use - just a simple press to talk, we are there to operate TV not talkback!

Solutions could include:

A dedicated digital voice channel/network - this strikes me that it should be easy but don't know anything about it - could we get handsets for £50 and set up a couple of channels?

A simple QO100 system with a box on the back of a small dish dumped on the ground pointing in the right direction.

A phone-based chat system that will work over 2G? Zello is OKish but drops out....

Something that piggy backs on Hamnet - it that works we could always offer to host nodes at home or at our TV repeaters?

Discuss.....

Noel - G8GTZ

radiogareth
Posts: 1215
Joined: Wed Jan 06, 2016 9:46 am

Re: Talkback - how can we improve it?

Post by radiogareth » Tue May 11, 2021 8:52 am

Agreed, on activity days with a good omni its impossible to actually arrange TB.
What about FreeDV, early days for me experimenting with it but less BW and specific freq. would fit a lot more in.
Or vertical beams?
QO-100 needs high spec stuff for NB as in stable and drifit free, plus the endless 'more gear'....
Keep discussing....

Gareth

g0mjw
Posts: 2330
Joined: Sat Sep 20, 2014 9:15 am

Re: Talkback - how can we improve it?

Post by g0mjw » Tue May 11, 2021 9:57 am

One solution for VHF/UHF might be plain old FM on the frequency and antenna used for DATV, or one of them, but with the same antenna. If you can't establish an FM contact the chances of a DATV one are marginal. Get everything aligned using FM, switch to DATV. Without two bands it isn't going to be duplex, but it doesn't require more hardware. The real problem with 144.750 talkback is those people insisting on using vertical antennas whereas the home stations are nearly always using a beam with much more gain and directivity. Hence the TV goes further than the talkback.

For the lower bands we are going to need to use a frequency that propagates in the same way, or the internet. Local solutions are not going to deal with Es. Zello would, or something like it. Very few good hilltop sites do not have mobile phone coverage, the problem is often too much mobile phone coverage and consequent co-channel interference. A directional antenna works wonders for that but mobiles don't have external antenna ports any more. So put the phone at the focus of a dish or corner reflector and use a headset.

Mike

G7JTT
Posts: 338
Joined: Fri Jun 10, 2016 5:05 pm

Re: Talkback - how can we improve it?

Post by G7JTT » Tue May 11, 2021 1:23 pm

As already stated conventional TB like with nb microwave activity has out striped it usefulness. Mobile phones either work well or not at all due to too many phone cells etc. DX spot and KST work well but need the internet. So what about getting a cheap data only dongle or GSM module and as Mike said using a directional antenna to over come the multiple phone cell issue. This would then hopefully give reliable internet. Then we'd just need to decide what application to use, but this must be low data usage to keep the costs down on what's likely to be a pay as you go sim ? Maybe a dedicated raspberry pi with a hat could be used ?

https://sixfab.com/product/raspberry-pi ... 8oQAvD_BwE

I have a dongle indoors I'll open it up later when I get home and look see if an external antenna can be fitted.

73 John

G8KOE
Posts: 178
Joined: Fri Aug 09, 2019 8:14 am

Re: Talkback - how can we improve it?

Post by G8KOE » Tue May 11, 2021 4:04 pm

Allstar system
Full Feature Repeater Controller
VoIP Full Duplex Linking with great audio
ASL/Echolink Linking
Simplex (half-duplex) Station
Autopatch and reverse autopatch
Frequency Agile Remote Base Station
Based on Asterisk - the Open Source PBX
Real-time status reporting to stats.allstarlink.org
https://www.allstarlink.org/
Easy to build Raspberry Pi sound fob.
https://www.youtube.com/watch?v=0lvmtZG ... terKendall
Above radio node by G7RPG you can also build a radio less node.
Lots of information from G7RPG
You can connect node to node direct or daisy chain them etc.

73's
Martin
G8KOE

M0YDH
Posts: 264
Joined: Sat Dec 31, 2016 5:59 pm

Re: Talkback - how can we improve it?

Post by M0YDH » Tue May 11, 2021 9:14 pm

2m SSB, 432 SSB or the microwave talkback frequency on 70cm FM would suit me. FT-857D is my rig of choice and I have all the gear with me when car park portable. Coming from SOTA, horizontally polarised FM in ATV land came as a surprise. I've used a lot of Zello on ATV days. G8GKQ insists on a 2 way radio contact before UHF TV is considered. I think that's fine.
No doubt you'll come up with something amazing- the club excels at this.
Cheers
David M0YDH

M0DTS
Posts: 653
Joined: Sun Feb 24, 2008 9:03 pm

Re: Talkback - how can we improve it?

Post by M0DTS » Wed May 12, 2021 9:35 am

I'm not very up to speed on the digital voice repeaters but surely the same applies as with analogue ones that there can only be one user at once?
No good for talkback in my opinion, although most are idle most of the time it would only take one other person using it to leave you with no talkback.

QO-100 talkback would be fun but just not practical.
Low data rate text comms via QO-100 is another option but will still require a dish etc.

I'm not leaving 2m talkback just yet...!

Send up a VHF repeater on a drone mid country for the day?
Starlink?
APRS - this has message facility and very good uk coverage... not sure if that would go down well but viable.

Talkback on the microwave freq is useful but again you need to communicate to set it up in the first place.

Hamnet is great but there's just no coverage and disappointingly very little interest in it. (apart from a development to the north of me)

That leaves us with mobile phones/internet, i used to struggle a lot with mobile coverage until i got a wifi hotspot on EE instead of my phone, seems to have solved all the problems.
I like Zello, worked very well the last couple of years.


Rob

G7JTT
Posts: 338
Joined: Fri Jun 10, 2016 5:05 pm

Re: Talkback - how can we improve it?

Post by G7JTT » Fri May 14, 2021 5:29 am

Just sen these at "The Pi Hut"

https://thepihut.com/collections/latest ... ositioning

Could either be used as a WiFi hot spot or maybe with the right software a dedicated terminal for talk back ? Seems to have a GPS as well so could even do the calcs, distance, bearing etc a bit like the WSJT does when you click on a calllsign calling CQ ?


73 John G7JTT

g8gtz
Posts: 1733
Joined: Wed Apr 07, 2010 6:26 pm

Re: Talkback - how can we improve it?

Post by g8gtz » Fri May 14, 2021 3:31 pm

Thanks for the useful comments.

I think I was hoping someone would say we can use some form of digital voice, there's good coverage from the repeater network, which will handle more than 1 channel at a time, we can set up a national ATV talkback room or local rooms and you can buy a handie or mobile for around £50 - well maybe £100!

In the absence of that, I guess 144.750 FM works OK, where I do run a horizontal beam and a vertical omni but people still don't hear you if you are beaming in the wrong direction. Alternatively, maybe try to improve the reliability of the mobile particularly for data, by playing with a dish or corner reflector, and use Zello and whatsapp messaging.

73
Noel - G8GTZ

AdrianH
Posts: 87
Joined: Thu Jul 18, 2019 2:46 pm

Re: Talkback - how can we improve it?

Post by AdrianH » Fri May 14, 2021 9:53 pm

I know I do not get involved with these activities as I have yet to get any portable gear, but is something like a mumble talk group not suitable, the sort of thing gamers use to talk amongst themselves as they play they are typically very low sever latency, if you are talking of things like wifi hotspots etc then you are talking smart phones and there apps for smartphones that do the talk groups?

I may be on the wrong track all together?

Adrian

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