SDS200 noise on RX only

[RidgeRunner01]

So I noticed yesterday that my SDS200 had this noise only heard on RX so bad the signals were unintelligible. I could probably post a clip from my audio recordings.

Anyways it sounded like a bad wall wart. Being used to these things. I got my battery pack and shut the unit down and got the DC power cable. I was preparing to shut my main breaker to see where the noise was coming from. I turned the scanner back on and before I killed the AC power. The noise was gone on DC, with my AC mains still on. OK well lets plug the AC supply back in, sure enough it's gone.

So power cycling my scanner got rid of my noise. Has anyone heard of this? Is this the infamous uniden noise I read about? Or something different?

 

[nessnet]

Chasing RFI - so much fun....

When you said you got out your "battery pack" "got the DC power cable", I am assuming this is the (car) wiring harness hooked up to some 12V battery? I ask, because doing this eliminates any interference coming in via power supply.

But, it also went away, so the noise had to have been coming from (or through) the (I assume Uniden OEM) AC/DC power supply...

 

[iMONITOR]

I've been using Uniden Scanners for decades and never had a noisy AC adapter. I don't think the noise you're hearing is the one numerous users have complained about. That noise is shuttle, kind of in that background.

 

[RidgeRunner01]

Chasing RFI - so much fun....

When you said you got out your "battery pack" "got the DC power cable", I am assuming this is the (car) wiring harness hooked up to some 12V battery? I ask, because doing this eliminates any interference coming in via power supply.

Yes exactly I used the supplied cigarette plug and one of those car booster packs. The plan was to turn off the main breaker allowing the scanner to stay on to see if the noise went away.

However before I shut the main breaker I notoced the noise was gone, thinking "ah-ha" noisey AC supply plug. I went to switch back and my theory was blown out of the water when the noise was gone. It would appear a simple power cycle resolved the issue.

I use proscan and I can see when exactly the problem started and it was not intermittent and it was happening on all frequencies.

 

[RidgeRunner01]

I should add that something was either going on internally in the scanner or AC supply because all that was done was a power cycle. This scanner runs 24/7 btw.

 

[iMONITOR]

I've been using Uniden Scanners for decades and never had a noisy AC adapter. I don't think the noise you're hearing is the one numerous users have complained about. That noise is shuttle, kind of in the background.

Meant to say "subtle", not shuttle.

 

[wtp]

i used to tell the kids..."listen to what i mean, not what i say"
i used humor usually instead of yelling at them. they knew if i yelled i did not mean it.
after telling a kid to do something they would start with "but dad"
and i would immediately yell back "don't call me butt dad"!
thanks for the correction.