Hello All,
I am working on interfacing a CDM1550 with GiaTronics ITA-2000a tone remote. It is all controlled by a Comtegra console. The CDM1550 being installed to replace a GM-300 for narrow banding. So far I have gotten the channel steering to work, but I am having some difficulty with the receive audio. When the GM300 was hooked up, I could key a portable, the CSQ light would illunimate on the tone remote and it would hear "dead air" (low level room noise) on the console. When I installed the CDM1550, I key the portable and the CSQ light comes on, but the console acts like there is no audio/call. If I start to talk, the console audio opens up and come right through, but then shuts off after I have stopped talking. It is acting like their is an audio gate or quasi-VOX setup.
Based on how the GM300 acted in the past and how the CDM1550 is acting now, I am suspecting the radio.
The only out of the ordinary thing that I am doing with troubleshootings is I made all the conventional personalities RX only. I don't have an antenna connection on my bench or a dummy load.
I hit google and couldn't come up with anything that sounded like what I am running into. Has anyone else noticed this? If so, how did you overcome it? Thank you in advance.
CDM1550 with tone remote issue
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techtonics
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Re: CDM1550 with tone remote issue
Before I can answer your question, what kind of channel are you using? Simplex or through a repeater?
Re: CDM1550 with tone remote issue
It's a simplex channel for testing.
Re: CDM1550 with tone remote issue
Could be the CDM RX audio is at a lower level or just quieter and the Comtegra is muting it, while I have never installed a Comtegra most consoles have wireline muting so you do not hear telephone line hum 24 hours a day. Below a certain level the audio is muted, once the audio threshold is met the console opens up and you hear the audio.
To test you could listen to the wireline before the console and see if you hear the RX audio or if the Comtegra has an option to turn the muting off try that.
As a fix you could try adjusting the RX sensitivty at the tone remote adapter upwards and see if that opens the console muting.
As an after thought was the GM set (via jumper) for flat or filtered audio, If flat the PL or DPL may have been geting thru and producing enough noise to open the console muting.
To test you could listen to the wireline before the console and see if you hear the RX audio or if the Comtegra has an option to turn the muting off try that.
As a fix you could try adjusting the RX sensitivty at the tone remote adapter upwards and see if that opens the console muting.
As an after thought was the GM set (via jumper) for flat or filtered audio, If flat the PL or DPL may have been geting thru and producing enough noise to open the console muting.
Cause Motorola said so that's why
Re: CDM1550 with tone remote issue
I suspect the GM300 had the jumpers moved to give it 'unsquelched' audio on Pin 11 at some point. You can set the same in the CDM through software.
In the CPS under 'Radio Configuration'--> 'Accessory Configuration' tab, try changing 'RX Audio Type' from the default 'filtered' to 'flat'. Let us know if that fixes things.
In the CPS under 'Radio Configuration'--> 'Accessory Configuration' tab, try changing 'RX Audio Type' from the default 'filtered' to 'flat'. Let us know if that fixes things.
No trees were harmed in the posting of this message...however an extraordinarily large number of electrons were horribly inconvenienced.
Welcome to the /\/\achine.
Welcome to the /\/\achine.
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chartofmaryland
- Batboard $upporter
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- Joined: Sat Dec 28, 2002 11:25 pm
- What radios do you own?: Alot
Re: CDM1550 with tone remote issue
I am afraid you have figured out one of the downsides to a Gaitronics TRA.
Pull it and replace the setup using a CPI TTP216.
Cpi products are Alot more stable at a lower cost than the Gaitronics.
The TTP 216 is more stable on Tx commands, decoding, and passing clean audio.
From the sound of it you are experiencing a problem with the DSP audio control inside of the ITA. The audio gates try to do more than they should to gate audio when a COR circuit does this same process in every other situation when COR is available. This appeared to be a feature for when COR was not available but cannot be excluded for applications like yours when you can provide a logic to tell when a valid carrier is present. I fought lost first syllables for a few rounds before 5 reads of the manual, and 3 phones calls lead to the conclusion where unless I cranked the audio in pot to the moon and set low frequency cutoff off so PL would open the audio gate the unit consistently would chop audio at the beginning of a transmission or the reception of a transmission.
Also, DO NOT attempt to pass sine waves through the box as they will not pass.
Sorry to hear you got an ITA2k, pulled many of these and put other things in their place along with quiet a few Vega TRA's.
CoM
Pull it and replace the setup using a CPI TTP216.
Cpi products are Alot more stable at a lower cost than the Gaitronics.
The TTP 216 is more stable on Tx commands, decoding, and passing clean audio.
From the sound of it you are experiencing a problem with the DSP audio control inside of the ITA. The audio gates try to do more than they should to gate audio when a COR circuit does this same process in every other situation when COR is available. This appeared to be a feature for when COR was not available but cannot be excluded for applications like yours when you can provide a logic to tell when a valid carrier is present. I fought lost first syllables for a few rounds before 5 reads of the manual, and 3 phones calls lead to the conclusion where unless I cranked the audio in pot to the moon and set low frequency cutoff off so PL would open the audio gate the unit consistently would chop audio at the beginning of a transmission or the reception of a transmission.
Also, DO NOT attempt to pass sine waves through the box as they will not pass.
Sorry to hear you got an ITA2k, pulled many of these and put other things in their place along with quiet a few Vega TRA's.
CoM
If the lights are out when you leave the station and then come on the second you key up, you know you have enough power.
Re: CDM1550 with tone remote issue
@ CoM...
Just out of curiosity, when did you have those issues with the GaiTronics units? The reason I ask is because I too had those issues, many years ago when they first came out. After about 2 years, they put new firmware in them that actually works exceedingly well in both COR and especially VOX configuration. We've been using them extensively without issue for the past 8 years or so.
Just out of curiosity, when did you have those issues with the GaiTronics units? The reason I ask is because I too had those issues, many years ago when they first came out. After about 2 years, they put new firmware in them that actually works exceedingly well in both COR and especially VOX configuration. We've been using them extensively without issue for the past 8 years or so.
No trees were harmed in the posting of this message...however an extraordinarily large number of electrons were horribly inconvenienced.
Welcome to the /\/\achine.
Welcome to the /\/\achine.
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chartofmaryland
- Batboard $upporter
- Posts: 411
- Joined: Sat Dec 28, 2002 11:25 pm
- What radios do you own?: Alot
Re: CDM1550 with tone remote issue
Wavetar,
It was a few years ago, 3-5 would have been when they were purchaed. Too bad they finally came out with a firmware solution. They seemed as if they would be a good platform but the audio handling was as we found, TERRIBLE.
That sucks for all of those who bought those that long ago. Hope there is a way to upload newer firmware so the old box will work better.
BTW, did this revision eliminate the need to head out to the location and pull power to reset the box from LA LA land? Cannot remember how many times I hated that service call until I was allowed to replace the unit with a CPI.
What was more sad was the shop I had worked at with the most of these, was selling them even in 1 frequency control applications!
568.00 from Tessco for an application when a 360.00 CPI single frequency box, worked all of the time versus the GaiTronics.
Sad story about passing tone, a Public Safety console lost its wireline control and a remote base was put together at the shop in a jiffy. Well, hurried out to the PSAP et everything up, started testing, audio passed but with delay, and then they tried to test paging to a station !!! Could not send QCII to save its life !!
Ended up waiting for the tropospheric ducting to die down on the microwave link and put the console back onto it. Needless to say, we bought a CPI and placed it in standby on a base radio should this have happened again.
What a bad day that was....
CoM
It was a few years ago, 3-5 would have been when they were purchaed. Too bad they finally came out with a firmware solution. They seemed as if they would be a good platform but the audio handling was as we found, TERRIBLE.
That sucks for all of those who bought those that long ago. Hope there is a way to upload newer firmware so the old box will work better.
BTW, did this revision eliminate the need to head out to the location and pull power to reset the box from LA LA land? Cannot remember how many times I hated that service call until I was allowed to replace the unit with a CPI.
What was more sad was the shop I had worked at with the most of these, was selling them even in 1 frequency control applications!
568.00 from Tessco for an application when a 360.00 CPI single frequency box, worked all of the time versus the GaiTronics.
Sad story about passing tone, a Public Safety console lost its wireline control and a remote base was put together at the shop in a jiffy. Well, hurried out to the PSAP et everything up, started testing, audio passed but with delay, and then they tried to test paging to a station !!! Could not send QCII to save its life !!
Ended up waiting for the tropospheric ducting to die down on the microwave link and put the console back onto it. Needless to say, we bought a CPI and placed it in standby on a base radio should this have happened again.
What a bad day that was....
CoM
If the lights are out when you leave the station and then come on the second you key up, you know you have enough power.
Re: CDM1550 with tone remote issue
I havent't been able to look at the post for a few days, as work has been keeping me busy. I am going to put my nose in the console manual to see if there is a gate/muting option. I will also try the RX audio type in the CPS.
FYI this tone remote is brand new...
FYI this tone remote is brand new...
Re: CDM1550 with tone remote issue
@Wavetar:
I tried both options, Flat and Filtered audio. I didn't notice any sort of difference. I'm going to be taking MassFD's suggestion and see about wireline muting.
I must admit that I am amazed that when I put the GM300 back in line, everything works as it should... It's always something.
I tried both options, Flat and Filtered audio. I didn't notice any sort of difference. I'm going to be taking MassFD's suggestion and see about wireline muting.
I must admit that I am amazed that when I put the GM300 back in line, everything works as it should... It's always something.
Re: CDM1550 with tone remote issue
A little update... my HT1000 that I was using for testing crapped out. I grabbed an EF Johnson 5100 and started using that as the testing radio. I was able to get everything to work perfectly after some adjustments with the RX audio pot on the tone remote. It seems that there was a vox issue on the Comtegra. Although I couldn't find anything documented in the manual. I am still a little stumped, but it seems to be working now. Just for grins, I am going to grab a 3rd portable and see if the results are any different.