TRX-2 problems w/P25 and NXDN

[Cameronkc7itp]

So, I have 2 Whistler TRX-1 handhelds that perform flawlessly, particularly when monitoring P25 and NXDN. So, after a lot of thinking, I decided to add a TRX-2 to the arsenal.

In a nutshell, I cannot get any P25 or NXDN transmissions to come through clearly on the TRX-2. Transmission come through very garbled, if at all. I have tried the telescoping antenna that the TRX-2 came with as well as my outdoor antennas, including the exact outdoor antenna that I use for the TRX-1. I get better P25 and NXDN performance on the TRX-1 with the rubber ducky antenna than I do with the TRX-2 on an outdoor antenna, which makes no sense to me.

All of the setting as far as DSP, ADC and DAC are identical in both the TRX-1 and TRX-2 radios.

Are there any adjustments that anyone can suggest? I just assumed I would get the same performance out of both radios.

Thanks all.

 

[n2pqq]

So, I have 2 Whistler TRX-1 handhelds that perform flawlessly, particularly when monitoring P25 and NXDN. So, after a lot of thinking, I decided to add a TRX-2 to the arsenal.

In a nutshell, I cannot get any P25 or NXDN transmissions to come through clearly on the TRX-2. Transmission come through very garbled, if at all. I have tried the telescoping antenna that the TRX-2 came with as well as my outdoor antennas, including the exact outdoor antenna that I use for the TRX-1. I get better P25 and NXDN performance on the TRX-1 with the rubber ducky antenna than I do with the TRX-2 on an outdoor antenna, which makes no sense to me.

All of the setting as far as DSP, ADC and DAC are identical in both the TRX-1 and TRX-2 radios.

Are there any adjustments that anyone can suggest? I just assumed I would get the same performance out of both radios.

Thanks all.

Try it with the att on showing G in display . Also you may have to try different squelch levels radio can be finicky

 

[Cameronkc7itp]

Thank You. I will give that a shot.

 

[tvengr]

I get better P25 performance on the TRX-1 with the rubber ducky antenna than I do with the TRX-2 on an outdoor antenna, which makes no sense to me.

It makes perfect sense. You are experiencing simulcast distortion. The problem is that there are several towers all transmitting the same thing on the same frequency at the same time. These signals arrive at your scanner at slightly different times which degrades the scanner's ability to properly decode the control channel. That results in missed transmissions, dropouts, and garbled audio. By using a smaller antenna or turning on the attenuator, you reduce the number of towers received which can improve control channel decoding. I would also turn off digital AGC. The AGC action can increase garbled audio problems.

 

[Cameronkc7itp]

Thank You....I just thought it was odd that the TRX-1 outperforms the TRX-2. With the exact setup in antennas, I figured they
would both perform darned near the same. I never have issue with garbled transmission on the TRX-1 on simulcast systems.

 

[Ubbe]

It seems that frequency calibration has a lot to do with how well it might handle simulcast. Also the TRX-2 are an old GRE design where as the TRX-1 are supposed to be a Whistler design and behaves differently, better, in some areas due to different hardware.

/Ubbe