GM300 Radius JU551 Flat Audio

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LukeR
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GM300 Radius JU551 Flat Audio

Post by LukeR »

Hello,

I have a GM300 Raduis (M34GMC29C3AA)that I want to use for a Ham Radio Allstar node that I am putting together.

That docs specify that: Radius receive radio must have JU551 in position 'A' (flat audio out).

I get on the web and look at all the information on JU551 and open up the top of my radio to set the jumper and cannot find JU551 anywhere. I did find P551 however

I would assume it's the function and it was set in position B. Can anyone confirm that it's the same and in Position "A" I will get flat audio out?

Also, does that flat audio out come from Pin 11 on the GM300 Raduis?

Thank you,

Luke -KK7XX
PETNRDX
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Re: GM300 Radius JU551 Flat Audio

Post by PETNRDX »

I have not seen one labeled P551, but there are only a few possibles of what it could be.
Check the audio coming out of pin 11 of the 16 pin accessory plug.
If it sounds like open squelch, then it probably is set for "flat".
The other position would be squelched and filtered.
Pretty likely that is the jumper you need to change.
Steve K.
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SteveC0625
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Re: GM300 Radius JU551 Flat Audio

Post by SteveC0625 »

LukeR wrote:Hello,

I have a GM300 Raduis (M34GMC29C3AA)that I want to use for a Ham Radio Allstar node that I am putting together.

That docs specify that: Radius receive radio must have JU551 in position 'A' (flat audio out).

I get on the web and look at all the information on JU551 and open up the top of my radio to set the jumper and cannot find JU551 anywhere. I did find P551 however

I would assume it's the function and it was set in position B. Can anyone confirm that it's the same and in Position "A" I will get flat audio out?

Also, does that flat audio out come from Pin 11 on the GM300 Radius?

Thank you,

Luke -KK7XX
In this article about half way through, there is a pic of the board with a pen pointing at JU551. That should help you locate it. http://www.repeater-builder.com/motorol ... -plug.html
LukeR
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Re: GM300 Radius JU551 Flat Audio

Post by LukeR »

Hello Steve,

The Article that you pointed me to about the 16 pin option/accessory connector is accurate & correct, however the board half way down is not correct. That is a MaxTrac board and it not even close to a GM300/Radius Board. I have been through that article several times to learn about the accessory connector. My board looks like the following pictures:

Picture of jumper P551
https://www.dropbox.com/sc/0op91h63mcko ... vw0TnxRU6a

Picture of GM300/Radius Board from the top:
https://www.dropbox.com/sc/p1ma5j7jj0sx ... pNU7e87e-a

Pen pointing to jumper P551:
https://www.dropbox.com/sc/3d1319b5st8b ... EwfdntXlna

Do you think P551 is the same as JU551

Thank you,

Luke
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Re: GM300 Radius JU551 Flat Audio

Post by PETNRDX »

Luke, I am sure that P551 is the same as JU551.
Besides that, you can't hurt anything by changing any of those jumpers.
You probably should go to the Repeater-Builder website, then scroll down to the Motorola section, then down to the Maxtrac, Radius and GM section, then finally the GM300 specific page.
There you will see everything you might want to know about the GM.
Even has pictures of the most common logic boards for those and the location of the jumpers.
I was reading that section last nite for another reason, and saw where the author had posted that there are some boards where they are stenciled with P551 rather than JU551.
Steve K.
LukeR
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Re: GM300 Radius JU551 Flat Audio

Post by LukeR »

Excellent PETNRDX that you for the information and thanks to you as well Steve, I appreciate both of you for the help, I really appreciate it. I have made the jumper connection as per the specs and will work on it tonight and let you know how it works and what I find out.

Best regards,

Luke
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Re: GM300 Radius JU551 Flat Audio

Post by PETNRDX »

I am kinda working on getting Allstar up and running to experiment with it.
Not really a ROIP person, but I have been told Allstar is much more stable than the others.
I got stalled trying to get Linux installed and running.
Then got distracted.
Steve K.
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Re: GM300 Radius JU551 Flat Audio

Post by motorola_otaku »

Yes, that is the correct jumper.

I'm assuming you're working off the URI documentation, so let me make a suggestion. Instead of using flat RX audio and letting the URI handle PL encode/decode, program the radio as you normally would, leave P551 at B (for muted/de-emphasized audio) and set your CTCSS to "none" in usbradio.conf. When working with AllStar and URIs it's always advisable to let the radio handle PL/DPL decode and just feed COR/PTT/audio to the URI.
LukeR
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Re: GM300 Radius JU551 Flat Audio

Post by LukeR »

Hello motorola_otaku, thank you for writing and yes, I am working off the URI documentation on: http://www.dmkeng.com/images/9080-GM300.pdf

I am able to receive, however I am not able to transmit. In other words, people can connect to my Allstar node and I can hear them, however, when I transmit, they cannot hear me at all. I am not using CTCSS either, I just wanted to test it with carrier operated squelch. I also tried it with a 114.8 tone and set CTCSS from DSP (decoding using RX audio in DSP). Still no joy.

I have another cable on the way so that I can wire as you mentioned above, however in the meantime, I would like to see if I can get this running for the interim.

I believe when I transmit, it's audio out or pin 11 that send audio to the URI. Would you know if that is something I would need to program into the GM300 using the DOS software or should it just work?

Thanks for any help you can offer, I really appreciate it.

Best regards,

Luke
LukeR
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Re: GM300 Radius JU551 Flat Audio

Post by LukeR »

Hello PETNRDX, thanks for your help and have you started on your Allstar project. I am half way there. I am able to hear stations that have connected to me, however they cannot hear me when I reply. I have tried just about everything I can think if with no success. I wired my GM300 per these instructions: http://www.dmkeng.com/images/9080-GM300.pdf

All wiring has been check and ohmed out as well.

Just wondering how you are coming along.

Best regards,

Luke
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Re: GM300 Radius JU551 Flat Audio

Post by PETNRDX »

Those connections look correct for the GM300 end. I didn't look up the Allstar end, but I would think you have those right.
Does your radio go into TX when it should?
If so, what does it sound like while listening with another radio?
No, I have not played with mine more yet.
Other things getting in the way.
I have not even gotten the Allstar Acid to install.
Steve K.
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