Scanner in vehicle noise ?

fires999

fires999

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Joined
Nov 16, 2014
Messages
161
Location
Hertfordshire, UK
Evening forum,
Hope this is the correct place to post? Apologies and administration please remove if not.
So over here in UK I drive an MG SUV vehicle. Its is fully petrol with no sign of a hybrid or electric motor.
Attached to my front air vents are 2 handheld scanners ( battery powered) so not plugged into any sockets. And attached to 2 magmount antennas at rear of roof.
One is a Uniden 3500 and the other a Whistler trx 1.
When driving or ignition switched on the 3500 is fine whereas Whistler turns deaf as though a massive attenuator has been switched on !!!
I guess it's the more complicated Whistler internals ?
Any ideas ?
Thanks in advance
Kevin (UK)
 
U

Ubbe

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Sep 8, 2006
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9,862
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Stockholm, Sweden
fires999 said:
Uniden 3500 and the other a Whistler trx 1.
When driving or ignition switched on the 3500 is fine whereas Whistler turns deaf as though a massive attenuator has been switched on !!!
Click to expand...
So when ignition are off both are fine?

The 3500 have a generally better receiver than the TRX-1, that's something I've noticed and 3500 are actually one the best portable scanners I have. But this issue seems to be related to some vehicle computer creating havoc with the TRX-1's reception. One thing to remember are that TRX-1 have a delay in it's reception, like in Unidens digital scanners Digital Wait timer, as it always work in dual Analog/P25 mode and waits to unmute the audio until it is sure of that it isn't a P25 data signal.

Open the scanners squelch so you hear the noise clearly and then turn on the ignition and listen for any changes in the sound that indicates its being interfered. If you set it to an analog channel that has some activity then open squelch and turn on the ignition to check if the signal disappears.

I have found that trying different places on the roof will let me find one place where interferences are gone. If I then drive by a wall of concrete or similar that reflects RF the interference from inside the car bounce and reflects back at the roof antenna. So the metal car roof stops the RF interference from the onboard computers to reach the antenna. If I try and use a scanners own rubber antenna I even get the whole VHF band full of dead carrier signals from the FM stereo radio and all other bands are full of ticking and data modulated sounds from the cars electronics.

/Ubbe
 
krokus

krokus

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Southeastern Michigan
fires999 said:
Evening forum,
Hope this is the correct place to post? Apologies and administration please remove if not.
So over here in UK I drive an MG SUV vehicle. Its is fully petrol with no sign of a hybrid or electric motor.
Attached to my front air vents are 2 handheld scanners ( battery powered) so not plugged into any sockets. And attached to 2 magmount antennas at rear of roof.
One is a Uniden 3500 and the other a Whistler trx 1.
When driving or ignition switched on the 3500 is fine whereas Whistler turns deaf as though a massive attenuator has been switched on !!!
I guess it's the more complicated Whistler internals ?
Any ideas ?
Thanks in advance
Kevin (UK)
Click to expand...
Which frequencies are you having issues with? At least is it VHF-lo, VHF-hi, 450 MHz, 800 MHz?

Any updates?
 
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