Tetra. Is anyone else using it?

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TRON
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Tetra. Is anyone else using it?

Post by TRON » 02 Jun 2012, 19:03

Ive been playing with Tetra for a while now.. Happened by accident really when I bought a job load of 4 Simoco SRM1000's some time ago. For whatever reason, I've stuck to digital ever since.
Is anyone else playing with Tetra at the moment?

Please PLEASE don't turn this into a thread full of "whats the point" comments. If you don't like digital, shake your head, call me names under your breath and move on please! :D

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Re: Tetra. Is anyone else using it?

Post by Arby80 » 02 Jun 2012, 19:07

TRON wrote:Ive been playing with Tetra for a while now.. Happened by accident really when I bought a job load of 4 Simoco SRM1000's some time ago. For whatever reason, I've stuck to digital ever since.
Is anyone else playing with Tetra at the moment?

Please PLEASE don't turn this into a thread full of "whats the point" comments. If you don't like digital, shake your head, call me names under your breath and move on please! :D
When you say "playing with tetra" what do you mean exactly?
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Re: Tetra. Is anyone else using it?

Post by TRON » 02 Jun 2012, 19:21

Well, me and a few others have been linking tetra mobiles over IP servers like Teamspeak for about 2 years. It was an unreliable pile of wires to begin with and sounded horrible, but now its pretty damn stable and sounds fantastic.
We have ALL had to learn some audio engineering and with limited output power from this type of radio have had to really get our antenna's in order to make the best of what we have.
Also, rather than use the usual soundcard interface's like the Signalink, I've built several of my own which offer zero noise floor, much better VOX sensitivity and far superior audio quality.
Schmitt trigger op-amps in comparator mode, audio stage impedance matching, DC decoupling... the list of things this project has taught me is endless.
Its as "Amateur radio" as I think it can get.

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Re: Tetra. Is anyone else using it?

Post by mr_h4ck3rm4n » 03 Jun 2012, 13:10

Been using Tetra for around four years, started as yourself with a load of cheap ex dolphin srm1k sets, progressed onto cleartone/motorola, with 25w from a repeater into a four stack antenna i have excellent coverage, the only problem with tetra kit is the low output power (3w for most mobiles) , the only higher powered radios are the sepura srg3XXX radios, these have a peak tx of 40dbm (10w) as standard, even this will only actually be around 8w (found this out using a racal digital site tester), the older srm1000 radios can have the output power adjusted using 'factory' software to around 15-20w max, the cleartone cm9000 radios can have the power adjusted to 20-25w using the service menu and the right equipment, most radios will only go as high as 430mhz without using 'modified' s/w or f/w

In dmo you are limited to simplex group calls or point to point calls (private) , SDS messaging and status messaging, gps can be used on some radios for AVL tracking via the PEI interface and the correct software (scout ect), no full duplex calls in dmo.

Using a dmo repeater with 25w into a fourstack dipole i have better coverage (usable) than when using a pmr setup of similar freq/power ect,

as far as using it for RoIP , yes the signalink picks up all sort of noise and need grounding, a home made interface may be the better option...

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Re: Tetra. Is anyone else using it?

Post by TRON » 03 Jun 2012, 14:20

Ok.. well here's the thing. Tetra (being UHF) has limited range, so the chances of two amateurs being "into" tetra AND being within range is quite low. This just about rules out point to point operation.

The next thing left is internet gateways. Ive been keeping my ear to the ground on this, and I am aware that there have been THOUSANDS of terminals sold on Ebay in the UK. Also, lots of the people who buy / sell this kit are setting up ROIP nodes on the likes of Loudtalks, Teamspeak and Mumble.

But where ARE they?!?! These systems appear to be totally closed loop, and people are deliberately separating themselves from others. With something like Tetra, this just doesn't seem to make sence? For instance, I notice you have a couple of Cleartone CM9000's.. I have one also. On mine, when I release the PTT, the radio seems to "end" the group/private call. This has made it a PITA to use for ROIP. Wouldn't it be better if enthusiasts of the same technology could talk using those gaping holes on the front of their faces (mouth's) about daft problems rather than type EVERYTHING in thier lives on a keyboard?

Hey! We own radios! We could talk with radios right? Oh, they won't reach. What about linking them via the internet? Nah.. better to segregate ourselves and struggle alone with any problems we face.

I don't get it? Am I missing something?

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Re: Tetra. Is anyone else using it?

Post by Wally » 03 Jun 2012, 22:07

I came across a guy on youtube in the Manchester area who had done just this, I was very fascinated and really want to join in. If you've got some kit floating about I may be interested, give me a PM and would love to join the ROIP side of things.
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Re: Tetra. Is anyone else using it?

Post by TRON » 04 Jun 2012, 20:09

@ Wally.

You probably have just about everything you need to set up an internet gateway. Try setting up with 446 handhelds or a GM360 and similar handheld etc...

Im sure we'll get onto "how to" later.. And I'd like to hear how other people have set up their systems, but for now, would be good for people to just pop up and say "yeah.. im using Tetra" so there's a kind of Tetra "register".

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Re: Tetra. Is anyone else using it?

Post by Wally » 04 Jun 2012, 22:02

I've got enough to get a 446 gateway up and running no problem but my location isn't fantastic. I'm trying to locate a suitable building/location for it that I can get access to but still fancy playing with the mototrbo/tetra side of things to see what I can do with that.

I've tested a few things with my Panasonic toughbook, acting like a parrot repeater etc and it worked well, though I was just using run of the mill Motorola PMR446 radios, I didnt have my intek 5050 at the time.
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Re: Tetra. Is anyone else using it?

Post by TRON » 04 Jun 2012, 23:09

Well there's nothing stopping you from setting up with Tetra. You'll need a base radio and a handheld for the most simple set up. Tetra terminals getting less and less common now though.
People are starting to charge silly money for them on Ebay which is daft.

Do you reckon you could get the GM360 up and running on ROIP? Believe it or not, it'll do a LOT of tricks that Tetra terminals wont manage in a month of sundays. It'll get you started until you get some Tetra \ DMR kit together.

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Re: Tetra. Is anyone else using it?

Post by Wally » 05 Jun 2012, 08:46

I've not got a GM360, I only have GP380's though I may have a GM360/380 in a few weeks. Im after a UHF set ideally. I presume I would need a signalink etc or is it fairly straight forward?

Thanks for your advice by the way :D
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Re: Tetra. Is anyone else using it?

Post by TRON » 05 Jun 2012, 17:27

It depends on what you want to do.. Do you want to connect to a server with loads of other enthusiasts and talk?
OR.. Do you want to connect to a private system between you and your freinds?

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Re: Tetra. Is anyone else using it?

Post by Wally » 05 Jun 2012, 20:15

Would rather have it connected to a server with other like minded people ideally. I've today, set up a 446 link that seems to be working, just a matter of getting the levels just right but so far so good.
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Re: Tetra. Is anyone else using it?

Post by TRON » 05 Jun 2012, 21:43

Right.. ok..

What radio's are you using? I take it you are using the inbuilt VOX in the node radio to get it to "PTT" when it gets audio from the PC?

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Re: Tetra. Is anyone else using it?

Post by Wally » 05 Jun 2012, 21:46

TRON wrote:Right.. ok..

What radio's are you using? I take it you are using the inbuilt VOX in the node radio to get it to "PTT" when it gets audio from the PC?
For the 446 i'm using my Intek 5050 with VOX. I was having a play around with the FRN client when the Intek's batteries needed a recharge ;-) :lol:
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Re: Tetra. Is anyone else using it?

Post by tetramoo » 09 Jun 2012, 18:53

I have tried and tested ToIP in the past and the voice audio clarity is unsurpassed....also I have to say that although most of the digital handsets in DMO are only 1W RF output...it's the mobile radios and a decent antenna system that make it usable, with coverage over quite a distance from mobile to base(vice versa).
More folk should 'embrace' digital radio technology and not be stuck in the dark ages of analogue with it's hissing,whining and white noise...although I have to say TDMA digital RF signalling when at the edge of coverage (deteriorates rapidly) will start to sound 'metallic and raspy'...then eventually your mobile radio display will indicate 'call failed' whereas analogue when it's on the verge of going 'tits up' will be just a hash of white noise.

Anyway that's my two penneth as they say...I tried it..tested it...it worked..and had some fun along the way.

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