eportel6607
Member
Guys I have four low power (under 20 watts) GMRS repeaters. They are all made up of Maxtrac 25 watt two channel models. The controller is a CSI TP-154 with two tones/users enabled.
Prior to using the tone panels I was using a simple repeater controller that worked well. In this configuration the PL encoding and decoding was simply programmed into the radios themselves. Since the two channel Maxtrac don't have the 16 pin logic board with all the necessary signals available I need to modify the radios to have the necessary signals at the mic jack. I've done this many times before but this is a bit different. In the passed I've really only need to get the COR signal to the mic jack. No big deal. I usually use the unused mic pin2 for this and grabbed the signal from the "RX Mute" circuit. The RX audio was taken from mic pin 8 which is "handset audio".
I can't use this method when using the tone panels for a few reasons. One, the handset audio is filtered...so the PL tone won't get passed to the tone panel and Two, the tone panel needs to be able to inject a PL tone into the transmitter...so the Maxtrac had to be modified.
Since there are only two pins in the Maxtrac's mic jack that aren't used (pin 1 and 2) I had to re-purpose a pin. I modified pin 8. As I said, this pin is normally filtered "handset" audio but I needed this pin to be used as an input for tone injection to for the transmitter radio. I severed the header pin from the front panel headers (J8) and made the necessary connections to make pin 8 function as needed. This part seems to work perfectly.
The issue is when a mobile/portable uses the repeater and unkeys it's transmitter the repeater has a long (about a 3/4 of a second) squelch tail. This happens every time a mobile/portable unkeys. This issue didn't exists prior to the radio mods. The RX audio source seems to be the issue. The connection for this audio were taken from the pins array known as "J6" which is the pins that connect the logic board to the RF board. Pin 3 on J6 is the discriminator....from what I understand. The audio is great sounding and is passing the tone to the control tone panel but for some reason I'm getting this squelch tail each time the repeater is used.
I've check the squelch settings in the radio and confirmed the setting on the TP-154 tone panel.
Anybody have any idea why this squelch burst happens each time a carrier drops?
Thanks guys,
C
Prior to using the tone panels I was using a simple repeater controller that worked well. In this configuration the PL encoding and decoding was simply programmed into the radios themselves. Since the two channel Maxtrac don't have the 16 pin logic board with all the necessary signals available I need to modify the radios to have the necessary signals at the mic jack. I've done this many times before but this is a bit different. In the passed I've really only need to get the COR signal to the mic jack. No big deal. I usually use the unused mic pin2 for this and grabbed the signal from the "RX Mute" circuit. The RX audio was taken from mic pin 8 which is "handset audio".
I can't use this method when using the tone panels for a few reasons. One, the handset audio is filtered...so the PL tone won't get passed to the tone panel and Two, the tone panel needs to be able to inject a PL tone into the transmitter...so the Maxtrac had to be modified.
Since there are only two pins in the Maxtrac's mic jack that aren't used (pin 1 and 2) I had to re-purpose a pin. I modified pin 8. As I said, this pin is normally filtered "handset" audio but I needed this pin to be used as an input for tone injection to for the transmitter radio. I severed the header pin from the front panel headers (J8) and made the necessary connections to make pin 8 function as needed. This part seems to work perfectly.
The issue is when a mobile/portable uses the repeater and unkeys it's transmitter the repeater has a long (about a 3/4 of a second) squelch tail. This happens every time a mobile/portable unkeys. This issue didn't exists prior to the radio mods. The RX audio source seems to be the issue. The connection for this audio were taken from the pins array known as "J6" which is the pins that connect the logic board to the RF board. Pin 3 on J6 is the discriminator....from what I understand. The audio is great sounding and is passing the tone to the control tone panel but for some reason I'm getting this squelch tail each time the repeater is used.
I've check the squelch settings in the radio and confirmed the setting on the TP-154 tone panel.
Anybody have any idea why this squelch burst happens each time a carrier drops?
Thanks guys,
C