Is the TRX-1 good for the UHF and VHF ?

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alabamarailfan

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Hello Jake,
For me, the TRX-2 (mobile version of the TRX-1) has been pretty good on UHF and terrible on VHF. I am currently using a Uniden BCD436HP and the VHF performance is certainly better.

See this post for more detailed information:
 

Ubbe

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It seems to have issues with overload and intermod at VHF. In UHF my TRX-2 has worse sensitivity than other scanners. The squelch on TRX are terrible and a useable setting will make it even more unsensitive. So weak signal monitoring are difficult and strong signal monitoring are difficult in VHF.

/Ubbe
 

devicelab

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A fairly inexpensive FM-trap filter can resolve a lot of these issues. Also your listening area may be bombarded with high-power NOAA transmitters which can cause significant problems on VHF. PAR makes a NOAA notch filter and it works incredibly well. It doesn't "wipe out" NOAA -- but it does reduce the received power levels substantially. Highly recommend it. I use the RTL-SDR FM notch filter which performs best for my location.
 

Ubbe

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I use a professional 2-way radio test set to check the receiver performance and have FM trapfilter and all my signals are in the -80dBm down to -110dBm, no big signals in VHF but still intermod in the TRX in VHF band. But it's like no intermod I've encounter before. The pager signal modulation at -80dBm are overlayed on every frequency in VHF. It is as if the modulation gets into the receivers oscillator and FM modulates the signal that goes to the mixer.

/Ubbe
 

devicelab

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The pager signal modulation at -80dBm are overlayed on every frequency in VHF. It is as if the modulation gets into the receivers oscillator and FM modulates the signal that goes to the mixer.
I see this on my SDR despite my filters.
 

vagrant

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I see this on my SDR despite my filters.
If you are specifically talking about pager tones in the 152 MHz area, Dale has a solution for that too. I use them on scanners and transceivers. Tell him what freq and he'll tune it and seal it. He'll send you unsealed as well if you ask, which is what I did, but you'll need a VNA or the like.

I would see a pager signal raise the noise floor on the waterfall each time it transmitted, and confirmed by listening to another receiver on the pager freq. While there are others near that range, one in particular was devastating. It is still there of course, but the filter throttled the noise floor as well as the pager tone intermixing with other carriers on different frequencies.

As to the topic, I do not remember specifically testing my TRX1 against my other radios on either VHF or UHF. I typically use the TRX1 for traffic via repeaters and they boom in here. Actually, it handles 40 MHz CHP stuff pretty well using a Diamond 77CA rubber duck. Still, that traffic is via a repeater.
 

Wackyracer

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I find better UHF or VHF reception by turning off the squelch tones especially on VHF. It made a big improvement for me on 155mhz, my old analog scanner still catches more VHF.
 
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