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FM Repeater to DMR Talkgroup? #best_practices


Weller Rudolf
 

Hello,

I would like to connect an analog FM Relais (Scanner) to my local HBlink-Server and transmit the audio signals to a DMR talk group, e.g. 777. This is intended for a local server, with no DMRPlus etc. connected, private only. Is there a guide for this, which I could read, or can someone here help me?

It'd already be enough if only the analog RX signal is transmitted to the talk group. How can I make this happen without the use of Crosslink, ASL, Echolink or multiple devices?

I have available: Raspberry, DVThumb, UriX and all this stuff here. What can I do?

Thank you
Rudolf


Mike KB8JNM
 

I can not point to a guide or give you much advise outside of this.

Be sure your audio is clean before converting to digital. Little noticed noise in analog can be a big issue in digital. Humming, buzzing and pops are not going to give you readable audio converted to digital. It's hard to believe how much it matters.

I do know you have a option for a rtl softradio input to allstar/asterisk connection and it is documented out there somewhere. Perhaps others will chime in with that and more info than I.

Connect it to a private node for control so you can connect/disconnect at will/as needed.

On 2/29/2020 12:34 PM, Weller Rudolf wrote:
Hello,

I would like to connect an analog FM Relais (Scanner) to my local HBlink-Server and transmit the audio signals to a DMR talk group, e.g. 777. This is intended for a local server, with no DMRPlus etc. connected, private only. Is there a guide for this, which I could read, or can someone here help me?

It'd already be enough if only the analog RX signal is transmitted to the talk group. How can I make this happen without the use of Crosslink, ASL, Echolink or multiple devices?

I have available: Raspberry, DVThumb, UriX and all this stuff here. What can I do?

Thank you
Rudolf


Mike KB8JNM
 

I am sorry, I missed the most obvious reply.

Set-up a node as you would a radio with the sound FOB and just use the audio input in VOX mode. Unless you can achieve a COR signal from the receiver. If you are using a Pi, VOX may be easiest.  Just set it up for a private node.

You should consult the allstar documentation for all that.

On 2/29/2020 12:34 PM, Weller Rudolf wrote:
Hello,

I would like to connect an analog FM Relais (Scanner) to my local HBlink-Server and transmit the audio signals to a DMR talk group, e.g. 777. This is intended for a local server, with no DMRPlus etc. connected, private only. Is there a guide for this, which I could read, or can someone here help me?

It'd already be enough if only the analog RX signal is transmitted to the talk group. How can I make this happen without the use of Crosslink, ASL, Echolink or multiple devices?

I have available: Raspberry, DVThumb, UriX and all this stuff here. What can I do?

Thank you
Rudolf


Weller Rudolf
 

Hey Mike,

I didn't necessarily wanna set up an ASL node. Are there other options? I was hoping to get a connection simply via MMDVM and Analog_Bridge, without an extra node. My problem with an ASL node is that it keeps a permanent connection, and I just wanna transmit to a talk group when analog FM is spoken. Kinda like a real radio device.

A COR signal is no problem, I have a Motorola GM360 connected to the URIx Interface

Thanks for the help
73 Rudolf


Mike KB8JNM
 

Well, the USRP interface is a A/D D/A bridge. Plugs right in to your mmdvm. But it's not really a A/D D/A converter since the format is all digital but one side is sourced from analog. It's really just a D/D format converter. In asl, the sound fob converts A/D. I have not 'seen' anything to the contrary but it may exist.

And the 'easiest' way to manipulate that is using asl. But you could bypass that. But I would be no help, except as I said in the first msg, a rtl-sdr may be what you want in place of your reciever. I know there are some doc's out there, however, I can't point to them. Google would help.

rtl-sdr --> usrp  --> mmdvm

On 3/1/2020 4:47 AM, Weller Rudolf wrote:
Hey Mike,

I didn't necessarily wanna set up an ASL node. Are there other options? I was hoping to get a connection simply via MMDVM and Analog_Bridge, without an extra node. My problem with an ASL node is that it keeps a permanent connection, and I just wanna transmit to a talk group when analog FM is spoken. Kinda like a real radio device.

A COR signal is no problem, I have a Motorola GM360 connected to the URIx Interface

Thanks for the help
73 Rudolf


Weller Rudolf
 

Hi Mike,
 
thanks for all your informations. I think i will get ahead. A great forum, by the way ... thanks to everyone!

73 Rudolf


Mike KB8JNM
 

Well, your only looking for ideas. Stick around for everyone to read and comment.
I would imagine you might also be able to pipe from a sound fob to the usrp.
Never done it, but I think it would be worth exploring.


David Martin
 

Hi Rudolf, Mike, 
I would suggest ASL with two 'private' nodes say 1999 & 1998 one connects to the URI the other USRP (Analog_Bridge).
Connect 1999 & 1998 at startup in asterisk. 
There is no ASL involvement the only permanent link will be to DMR through MMDVM_Bridge.

Just a thought or two
David Martin VK3KQT


On Sun, Mar 1, 2020, 20:47 Weller Rudolf <t4.vw-bus@...> wrote:
Hey Mike,

I didn't necessarily wanna set up an ASL node. Are there other options? I was hoping to get a connection simply via MMDVM and Analog_Bridge, without an extra node. My problem with an ASL node is that it keeps a permanent connection, and I just wanna transmit to a talk group when analog FM is spoken. Kinda like a real radio device.

A COR signal is no problem, I have a Motorola GM360 connected to the URIx Interface

Thanks for the help
73 Rudolf


Weller Rudolf
 

Hello David,

that's a very interesting idea. I tried private nodes twice now, but it doesn't really work. I think my rtp.conf has the wrong configurations for nodes 1999 & 1998.

DMR to analog seems to work. When I press the PTT on the DMR device, I can hear the CW output and an acknowledgement sound from the same device, but no sound whatsoever from the FM device. No red LED signal on the UriX either... When I press the PTT on the FM device instead, nothing happens at all, and DTMF sounds aren't recognized either.

When I enter "rpt cmd 1998 cop 4 1998" directly into the Asterisk-shell, I can hear the sound from the DMR device and - with 1999 - also in the FM device. So the UriX seems to work. The startmacro in my rpt.conf is *31998.

When I enter "rpt cmd 1998 ilink 3 1999" into the Asterisk-shell, I can speak from DMR to FM, not the other way round though.

When I enter "rpt cmd 1999 ilink 3 1998" into the Asterisk-shell, neither DMR nor FM work. All I hear is a rogerbeep in the DMR device.

Maybe someone can help, cuz I'm at my wit's end.

1999 - UriX
1998 - USRP
Raspberry Pi 3 B+
Allstarimage von DVSwitch.org
 
73 and take care
Rudolf