TRX-1: Control Frequency

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With my Pro 106 I was able to hear the Controller computer on the Control Frequency(ies). So why cannot not hear the Controller on my TRX-1. I know that the trunked systems work that I programmed, I just cannot hear the Controller.
 

Whiskey3JMC

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So in other words you're asking why you can't hear the data noise emitted from the control channel? Most of today's scanners (I can at least speak for Uniden's x36's and SDS's and the TRX's) squelch this noise by default. Aside from being an audible indicator of an active frequency, why would one want to hear data noise when the control data and signal strength bars are displayed on the screen?
 

Flatshovel

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I had that same issue when I got my TRX-1, I for one would like to hear the control data, then at least you would know what it is when you hear it. Just saying.
 

dem1

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If I understand the question correctly, one can hear the control channel by either (1) turning on the TRX-1's "IF Output" function in Program Menu > Global Settings, or (2) programming the control channel as a conventional analog object.

Note that something must be plugged into the headphone jack for the IF Output function to work, even if listening through the speaker.

I find it useful to listen to control channels as a diagnostic tool when reception is difficult. Is it a clean sounding signal or one laden with cellular interference? Does it sound better with the attenuator on or off? Does repositioning the radio make a difference? Maximum strength on the signal meter alone could simply indicate maximum overload from a nearby cellular site.

A P25 LSM/CQPSK control channel signal has a very pronounced 4.8 KHz whine when monitored as an AM analog object. With a fully open squelch it can be heard even when the trunking signal is too weak for the TRX-1 to decode. So in a fringe area with no whine, there's no point in even trying to pick up the system. When I start hearing the whine, I give it a go.
 
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g6fgy

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There's at least one advantage to having the data channels auto-muted. When scanning/searching the scanner briefly pauses on a busy channel to check for voice data, then automatically steps on in none is present.

I find this much better than having the scanner stop on a data channel then needing to manually step over it, particularly if I'm out & about with the scanner in my pocket. I just wish it'd auto-mute for the MPT 1327 control data too
 

Ubbe

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I would like to have a monitor button on all scanners, that unmutes so that I can listen to the raw audio signal.
Maybe Whistler could consider making the ATT button work as an unmute button when held for longer than 1 sec and then mute again when it was released. Or Fn+ATT toggles unmute if that's easier to do and don't infringe any patents.

/Ubbe
 
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