[600MRG] 630M Noise Reduction

[Paul Signorelli]

During my spectrum search around the shack for noise sources,
I came across a big data burst on the LoJack frequency (173.075).
It was swamping my HT receiver. I have a tin coffee can that I use as a shield for really strong signals to prevent overloading. My FT-411 and Baofeng UV-5R are both poorly shielded so I put the UV-5R into the can and attached a 60 dB variable attenuator and went out side hunting.
   I didn't use my beam because it is now tuned to 146 MHz.
The UV-5R doesn't have an S meter, so I just opened the squelch and had lots of hiss noise to
detect the signal. The LoJack is a data burst (1-2 seconds every 65 seconds).
You have probably seen the police cars with the 4 - 17 inch meter whips on the roof. They do T Hunts automatically. I don't have one of those.
   Well, I walked up and down the block switching from 30 to 40dB attenuation and the LoJack signal was really strong. There was only one car around that is a spare car parked next door.
I was able to click in 55dB attenuation and still strong at the car. I went over to the passengers side rear window and got 60 dB and could still hear it. Then I saw the antenna. 2 little black vertical black stripes on the window, It is a FORD.

   The police probably get a lot of these false signals. Distance from my shack was 50 feet. Real DX 'T Hunting'. I arrived with the lowest mileage.
   The owner didn't even know what 'LoJack' was. I told him to take it to the dealer and reset it.
It is like 'Probable Cause' for any Police T Hunter to stop you, (Felony Stop with pistols).

Paul   w0rw

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