radius M1225

[shanebohannan]

I am sorry if this has been asked before but i searched and did not see the answer.


I have a M1225 setup on amateur radio 2 meter, and am trying to setup echo link to link to one of the local repeaters.

I used the accessory pins in the back and when to a 9 pin RS232 to plug into the back of the computer that will be used as the echo link server.

My issue is when i plug 9 Pin RS 232 into the back of the computer the radio goes into transmit and does not do anything.

my pin out from Accessory plug to RS 232

Accessory plug rs 232
Pin2 Line out + plugged into Mic jack of the computer flat audio in for the software
Pin 3 Pin 2 Mic PTT allows software to TX
pin 7 Pin 6 ground has both line in and out grounds
Pin 8 Pin 7 Program I/O ?????
Pin 11 Pin 8 RX audio + plugged into speaker jack of computer


If i missed anything or if you need more info please let me know.


Thank you
Shane

[Will]

You need a interface in line between the computer RS232 and the radio. You may also need a filter for the transmit audio.

[kb4mdz]

Pin 8 of the Access. plug is often used for COR or PL Detect or similar;

And pin 2 of a 9-pin serial port is Transmit Data;

PTT on M1225 ( or maxtrac, or CDM1250, or. . ..) is active LOW; I'm betting that the 9 pin port is pulled low, therefore sending radio into TX.

What are the instructions you're using?

[shanebohannan]

i found 2 different sets of pictures that i was building my cable from. I will post them with this post. I am not sure i follow you on "add pin 2 of a 9-pin serial port"

this is where the cable idea came from, i know the radio is different but the pins workout to be the same.
http://www.repeater-builder.com/motorol ... r1225.html

the Picture is toward the bottom of the page



This is the second one i found that makes me think i do not have all the connections i need.
http://wiki.argentdata.com/index.php?title=OT-Moto


Sorry i did not see how to post pictures.

[kb4mdz]

Not sure, but I think I see your problem.

If you look at the schematic near the bottom of the Repeater-Builder page you reference, you'll see in the diagram (which is below the picture of back end of a GR1225 radio, ) you'll see that that next diagram references the DB-9 connector as going to the IRLP Board Connector; it doesn't plug into the serial port of the computer.

Look at p. 5 of this document:

http://www.irlp.net/new-install/Ver3_Wiring.pdf

you'll see Pin 2 of that 9-pin is PTT; so backing up, yes, if you're plugging your radio interface cable into the computer's serial port, and the PC tries to transmit data out thru Pin 2, yes, the radio will key up.

Just conjecture on my part; I freely admit I can be all or partially wet.

[shanebohannan]

Ok i think i am starting to catch up.

Correct me if i am wrong here (i have been that way before).

For the radio to communicate to the computer or the computer to communicate to the radio there will have to be some type of interface between them?
something like westmountainradio rigblaster, or tigertronics signalink?


Thank you
Ki4ehn

[kb4mdz]

Yes, I think that's it.

[shanebohannan]

Do you know of a homebrew version that is usable? I was hoping the cable would be enough but I struck out with that thought.

Thank you for all your help kb4mdz. 73's

[pete01]

The problem I am having may fall along this thread.
I have a home made computer/radio interface, a modified WM2U. My issue is with the PTT. The M1225 does not return to receive (PTT locks up) after the interface is done sending the transmit signal. The interface unit works fine with the GM300, no issues. I checked the pinouts of the accessory of the two models, no difference.
is this a radio setting issue ? And if so which one(s) ?
Thanks
73's pete01

[Jim202]

Have you taken a look at the site www.batlabs.com and then gone to the equipment section? If you go there, then find the mobile or base station section, you should find some information on your radio.

There is also a section on the programming interface box (RIB) that is normally needed to go between the radio and your computer serial 9 pin interface connector.

There should also be information on the programming interface cable that you probably can make yourself. It only takes the connectors, the cable, some soldering and time.

I have made my own programming cables for most of the radios I use. The only ones I bought are for the newer radios that use the USB interface like the XTL, APX mobiles and some of the newer portables like the XTS and APX.

Jim

[pete01]

Thanks Jim for the reply.

I did go back and read some more in equipment section that has promoted me to go over to a friends and discus this situation and take some voltage reads readings for reference, will post our findings later, got to get ready for work now.

[Bill_G]

The problem I am having may fall along this thread.
I have a home made computer/radio interface, a modified WM2U. My issue is with the PTT. The M1225 does not return to receive (PTT locks up) after the interface is done sending the transmit signal. The interface unit works fine with the GM300, no issues. I checked the pinouts of the accessory of the two models, no difference.
is this a radio setting issue ? And if so which one(s) ?
Thanks
73's pete01

AFAIK the PTT in both models is essentially fixed, and cannot be modified in the RSS or with internal jumpers. Obviously the circuit you built goes low enough to pull in PTT, but doesn't raise enough to stop the M1225. I'm assuming you used an open collector circuit. Without looking at both radio's schematics, I'm guessing you need a medium value resistor (>1K) to 12V to pull the line back up. Or you could insert a small relay. Have your circuit drive the relay, and the relay closure applies PTT to the radio.

[pete01]

I was using an Opto Isolator, as depicted :http://www.qsl.net/wm2u/interface.html. Swapped it out for the 2N2222 circuit, also shown on same page.
I have had some success with this new circuit but, only when I transmit with the ground of the my Oscilloscope connected to the ground of the PTT circuit (it transmits and then returns to receive as it should) . When I remove this ground, no joy, no transmit at all. Put the ground back , it works. Tried grounding the PTT circuit to pin 7 of the accessory, blew out the pico fuse inside the M1225. (I won't try that again). Any suggestions ?

[Jim202]

I was using an Opto Isolator, as depicted :http://www.qsl.net/wm2u/interface.html. Swapped it out for the 2N2222 circuit, also shown on same page.
I have had some success with this new circuit but, only when I transmit with the ground of the my Oscilloscope connected to the ground of the PTT circuit (it transmits and then returns to receive as it should) . When I remove this ground, no joy, no transmit at all. Put the ground back , it works. Tried grounding the PTT circuit to pin 7 of the accessory, blew out the pico fuse inside the M1225. (I won't try that again). Any suggestions ?

I would have to question that you were really on the correct pin 7. There is no way you would blow the pico fuse by grounding the real pin 7.

There is a service manual available on the repeater builder sit. On page 4-2 of the service manual is a diagram of the accessory connector. it is real easy to get turned around on that style connector. My thought is you might have got on pin 10 by mistake.

Jim

[pete01]

You are correct, I was on the incorrect pin. And I see that the PTT circuit is grounded there already,the bare wire of the accessory of connector cable.
(pin ten was the mistaken one)
pete01

[pete01]

Update.
If I run a jumper, from a ground point on the laptop, that I am running the software on, to the previously mentioned ground point (pin 7) all is fine.........
pete01

[pete01]

Apparently, my SERIAL to USB converter does not have a shield (from to shielded cable SWE) that goes all to way through, electrically speaking. So from the term strip located in the interface box, I found the term that goes to pin 7 of the accessory connector, ran a wire outside the interface box, stripped some insulation off the SWE cable of the SERIAL to USB converter, soldered that wire to the shield. It works.

Thanks for the suggestions guys and thought provoking ideas that I needed.
73's Pete