Batboard

Guys


I built a repeater interface cable (diagram posted by nand), my buddy and i just programmed up my cdm1550(main) and my m130 (linker) MOD>(m44xqc20a4aa). I have two problems, the ,major one is that we are unable to get a COR signal out of the M130 to alow it to talk to the CDM. From the CDM thru the M130 to a portable it works ok, but when i talk thru the m130 from a portable to the cdm, the cdm won't transmit. The Accy pins on the CDM are programmed ok (checked twice)
The m130 does not have a programable 16pin connector, the rss only allows me to do the normal programing. The cable appears to be put together ok so nearest i can tell mabee the radio is not right? I thought the default for non programable pins was #8 was defaulted to COR, that does not seem to be the case. Is there any kind of internal jumper or modification i need to make to the m130 to get the COR out to the accy conector. I am sure of the model (m44xqc20a4aa).


The second problem it that od DEsensing of the CDM. When the M130 transmits the recieved traffic from the cdm the portable hears some audio but the traffic is all garbled. The two antennas are about 18-24 in appart , and the frequencies in the linker are about 2mghz appart from that of the CDM repeater pair. I am thinking if there was a way of turning the power on the M130 way down (from 40w) to a watt or two the front end of the CDM would behave better. Is there a way of turning down the power of the M130 easily?


any suggestions would be appreciated.


thanks

Radiogeek97 wrote:Guys


I built a repeater interface cable (diagram posted by nand), my buddy and i just programmed up my cdm1550(main) and my m130 (linker) MOD>(m44xqc20a4aa). I have two problems, the ,major one is that we are unable to get a COR signal out of the M130 to alow it to talk to the CDM. From the CDM thru the M130 to a portable it works ok, but when i talk thru the m130 from a portable to the cdm, the cdm won't transmit. The Accy pins on the CDM are programmed ok (checked twice)
The m130 does not have a programable 16pin connector, the rss only allows me to do the normal programing. The cable appears to be put together ok so nearest i can tell mabee the radio is not right? I thought the default for non programable pins was #8 was defaulted to COR, that does not seem to be the case. Is there any kind of internal jumper or modification i need to make to the m130 to get the COR out to the accy conector. I am sure of the model (m44xqc20a4aa).


any suggestions would be appreciated.


thanks

As someone who has built up heaps of Nand's interfaces now, are you running both the tx & rx of a common power supply ?

The ground path on both radios needs to be the same for it to work

That's my first thought.
Regards
Michael
Melbourne, Australia

MIKE
the radios both have a comon ground, they are installed in a console and there is a ground lug that is comon to all the equipment located in the consolidator console.



thanks for the quick reply

Pin-8 on the m130 is definitely open collector COR. When both radios are connected together, can you ground pin 8 on the M130? This should key the CDM radio. If not, check the programming for accessory pin-3 for the CDM radio. It should be active low, the default setting.

As for the desense, if you are running both radios on UHF, the antennas need to be spaced 1800 feet apart for 2 MHz frequency spacing when using only 1 watt of power. This clearly is not possible for a vehicle.
For this to work without some sort of duplexer, you need to run one radio at VHF and the other at UHF.

A possible option would be to mount the link antenna under the vehicle for added isolation and increase the frequency separation between the radios to about 20 MHz. This works better on VHF than UHF for in band repeating.

Nand.

When you say, “not transmitting”, do you meant no TX audio or no TX period?

Nand.

hi nand

1800ft it's hard to park that baby now geez, unfortunately i need both radios in the same band. What i am trying to do is cover dead spots in our coverage area and not have to use 2-different portable radios. i have a mag mount base that i could give the "undermount antenna a try.
As far as the COR signal I will give grounding the m130 #8 a test, and to ans your question the CDM does not x-mit at all. The cdm does talk through the m130 to the portable, but not the other way. I can hear the auido from the m130's speaker but it is not getting pumped through the connector to the CDM Thanks for your tips I will try some further troble shooting.

nand

i checked the archive for my cdm, and the setting of pin#3 is ext mic pt (imput) active level is set to low and debounce is checked.

Nand/fellas



i looked over the radio(s) and grounded pin #8 on the m130 and the cdm keyed up! Does this mean that the m130 has somthing malfunctioning?


take care and thanks

Is far as I know, the M130 pin-8 should go low with a carrier and valid (correct) PL if programmed so. My guess is that the transistor driving the COR line (pin-8 ) is faulty, unless I am wrong with respect to the M130. The links below show that you may not be alone but do not give a conclusive answer. Perhaps someone with a M130 manual or radio can give you some help here.

http://batboard.batlabs.com/viewtopic.php?t=19415
http://batboard.batlabs.com/viewtopic.php?t=8633

Nand.

nand
thanks you have been Very helpful! If sombody else hase further information that would be great, i hate to dump this radio #1 it was free (and this may be why) #2 it is a rare split (460-495) and i can use that bandsplit to my advantage in trying to keep some frequency separation to eliminate the need for a duplexer, hopefully.


thanks all