Whistler TRX1 scan speed drops drastically when plugged in.

[JohnnySmith81]

Hey all. Newbie here who's been a long time reader on this forum, but now its time for my first post. I'm hoping someone can give me a bit of advice, or know whats going on here.

I recently got myself another Whistler TRX1 after misplacing my old one i got years ago, but i'm having an issue which i noticed a few days ago.

When the scanner is running on battery power, the Spectrum Sweeper acts as it's meant to, in that it almost instantly scans through very large portions of frequencies.

When i run the scanner plugged in via the supplied power cable (usually in my car), the sweep speed reduces dramatically to where its taking almost a second per full step. I.e, 140.000 - 141.000 for example.

I initially thought maybe it was detecting signals and slowing down within certain portions, but there is no signal strength showing at the times when it is going slow.

I have also tried multiple antennas but get the same results. As soon as i pull the power cable from the scanner, the speed jumps to be almost instant.

Does anyone know why this might be the case? This only happens when plugged in to a power source and thus means a lot of missed transmissions. I'm not to sure my old one did this, so i'm kind of hopeful it's a settings issue. It's annoying me now i have noticed.

Thanks in advance.

 

[buddrousa]

Does this only only happen when plugged in the car?
If so you have a high RF level coming from your car. Car Computer LED Lights or some other source.

 

[JohnnySmith81]

Does this only only happen when plugged in the car?
If so you have a high RF level coming from your car. Car Computer LED Lights or some other source.

I will have to do some other tests plugged into another supply, but yes i have only noticed it when it has been in the car. I'll try a power bank even later tonight and see if that helps, as it runs perfectly in the car on battery power. Many thanks for the reply.

 

[Ubbe]

The 5v power supply are using a switching circuit design to change the voltage and a poor design can emit a lot of RF interference. It sounds as that could be your problem and any poorly filtered power supply will use the cable as an antenna to transmit that RF interference to your scanner.

Also TRX scanners have a huge frequency range at VHF for its bandpass filter, 108-200MHz, so it will suffer more from interference and overload in the VHF band than other scanners that have divided up VHF in several different bandpass filters. A FM broadcast filter are really needed.

/Ubbe