We are currently using pin 2 to inject audio on an aux rx. It does not sound to good. To much highs. I cant figure out why we cant get the flat audio pin 5 to work. What am I missing?. It works with pin 2 but I need flat audio. HELP
Rich N2ROW
927.9625/R NYC
PS I tried 3 radios[/b]
GTX 900 Need help, pin 5 flat audio input wont work?
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I tried it on one of my radios - it doesn't work either. Pin 2 works fine if you use the pin 3 PTT.
I checked the schematic. Pin 5 goes through an op-amp then to an ASIC pin labelled AUXTXIN. I don't know what activates that input. I tried tone into pin 5 and used both front and rear PTT lines - still nothing.
I don't remember anything in the RSS that would activate that line.
If you're getting too much high frequency response, it sound like you're using a flat RX output, which would have too much HF response. Try using a de-emphasized RX signal and feed that into the MIC input which will pre-emphasize the signal when it's transmitted.
I guess you'll have to use a MaxTrac as a transmitter. They're better suited for repeater use anyway.
Bob M.
I checked the schematic. Pin 5 goes through an op-amp then to an ASIC pin labelled AUXTXIN. I don't know what activates that input. I tried tone into pin 5 and used both front and rear PTT lines - still nothing.
I don't remember anything in the RSS that would activate that line.
If you're getting too much high frequency response, it sound like you're using a flat RX output, which would have too much HF response. Try using a de-emphasized RX signal and feed that into the MIC input which will pre-emphasize the signal when it's transmitted.
I guess you'll have to use a MaxTrac as a transmitter. They're better suited for repeater use anyway.
Bob M.
GTX 900 audio
Rich,
I'm not familiar with the GTX, but I would assume, being "flat audio", that the signal is taken before the deemphasis network in the receiver, therefore you would be hearing audio with a lot of highs from the preemphasis in the transmitter. This output is probably used for signalling and the like where the preemphasis would not be an issue. Just a thought.
73 Tom KB5DPE
I'm not familiar with the GTX, but I would assume, being "flat audio", that the signal is taken before the deemphasis network in the receiver, therefore you would be hearing audio with a lot of highs from the preemphasis in the transmitter. This output is probably used for signalling and the like where the preemphasis would not be an issue. Just a thought.
73 Tom KB5DPE
GTX 900 audio
OOOPS! I should have read Bob's reply first. Sorry.
Tom
Tom
The reason is because we are using the radios as Tx's for a voter system. We were able to shape the audio some. But its just not right. Our 900 mHZ repeater uses a spectra radio and it sounds great. But since we invested on these GTX for linking we need to get it working. That pin 5 has to activate some how. My partner is going to try to ground pin14 to see if that activateds that audio path. Otherwise he is going to try to by pass the compander chip in the audio line. But we need the info posssible. That pin 5 is there for a reason. If your able to test it let know. If we get it to work we will advise. GTX as a low link radio works great. Its just this audio problem we would like to inhance.
Informed sources tell me that the TX AUDIO INPUT does not work unless you have some specific firmware version, probably on the latest radios. These will also have a tiny DIP switch on the board that would be used to enable/disable Ignition Sense. I've seen four GTX mobiles and none have any DIP switches in them, nor does my service manual, so all of mine must be terribly old, which means about 10 years in Moto-speak.
You might have to dig into the radio to get something that will actually work the way you want it to, but it seems for now, you're out of luck.
Bob M.
You might have to dig into the radio to get something that will actually work the way you want it to, but it seems for now, you're out of luck.
Bob M.