Scanning two close frequencies with different squelch codes

[smr2x]

I've got two local businesses that use 153.0125 and 153.00500. One uses DCS and the other uses CTCSS.

If I'm in the middle of them geographically, my TRX-1 will pick both up separately and use the right codes, but will also get confused and combine them or jump between them if both are transmitting at the same time. Is there a way to distinctly separate these in the scanner, or is this kind of interference/mixing normal?

Thanks!

 

[KevinC]

Those are 7.5 kHz away from each other. Scanners aren't selective enough to be able to separate frequencies that close (and neither can professional radios if the signal strength is high enough).

 

[smr2x]

Those are 7.5 kHz away from each other. Scanners aren't selective enough to be able to separate frequencies that close (and neither can professional radios if the signal strength is high enough).

Thanks! I figured that was the case, but wanted to be sure I wasn't setting them up incorrectly. I appreciate the quick reply.

 

[rayvelcoro]

I agree with Kevin C. A good example that I frequently see in my bustling downtown area : low power business walkie-talkies on 461.13750 Mhz and 461.13125 Mhz bleed over onto each other depending on relative signal strength.

 

[Mike_G_D]

What the others said above is basically correct. If the strength of the signals is high enough there isn't much you can do. But just in case make sure you use the narrow FM, NFM, modulation/mode setting if you aren't already doing so. The GRE/Whistler scanners do have a decent narrow filter when switched to that mode unlike the older Uniden's (436's and newer also have a true narrow FM filter when switched to FMN but the older models just changed audio and maybe discriminator characteristics and used the same IF filter for both FM and FMN; "FMN", by the way, is Uniden terminology while GRE/Whistler uses "NFM" - means the same). Like I wrote above, though, may not help much if the signals are strong but figured I would throw it out in case you haven't already tried it.

-Mike

 

[Ubbe]

There are two IF filters in the TRX scanners, one FM and one NFM. Choose NFM manually and not automatic just to be sure you use the NFM one.
Try setting both frequencies 2,5KHz wider apart, 153.0025 and 153.0150 and you might have to enable Flex Step in the menu to be able to do that.
You could also try 3,25KHz wider apart if necessary but it might sound a bit distorted at lower signal strenghts.

/Ubbe

 

[smr2x]

Thank you all for your help and suggestions. I've got these changes set up and ready to test tomorrow. I'll let you know it goes!