The persistent travelling birdie

[Tim-B]

Here is something I have wondered about for years and it has affected every scanner I have owned which totals 19 scanners. Say you are using the search function to search a range of frequencies and you come upon some weird static. You press whatever button you have to press to make the scanner keep going. Then when it comes to that frequency again you hear the weird static again so this time you lock it out and the scanner begins searching again. A second later you hear the same weird static on another frequency close to the one you just locked out. Now mind you, the static was NOT on that particular frequency before you locked out the first one. So, you lock out the second one and keep going. Now it comes up on a third frequency and again it was NOT a frequency where the static existed before you locked out the first two. So you lock that one out and keep going, then it happens again, and again, and again, one one frequency after another. That same weird static. It just HAS to find an out for itself and bug you no matter what. You check the squelch and turn it to a higher setting but the travelling static persists. Now it doesn't happen every time you search this band but only occasionally. It seems to pick a particular day to annoy you.

What causes this? It has happened to every single scanner I have owned over the 32 years I have been scanning.

 

[johnnyelectron]

Radios just have 'built-in' "Birdies" - that's where the I.F. frequency of the scanner mixes to cause bogus 'stations' on your scanner. Some triple conversion scanners seem better at reducing the scanners, but some you can't get around. I even have an expensive professional Vertex radio, and it has a 'birdie' right on 146.61- a local repeater output. I have to use PL tones so it doesn't stop on that channel 24/7. A new one is that I get harmonics off of the hardwired Ethernet cable that drops bombs all over the ham 2-meter VHF band. Maybe someone else can describe it better, but these 'birdies' are even listed in some scanner manuals.

 

[ladn]

Interesting problem. Perhaps you could provide some details of your scanning environment (base/mobile, other nearby radios or electronic equipment).

I've experienced similar issues on occasion when I had several scanners and a vhf two way radio in my vehicle. The vehicle was old enough so I could rule out the onboard computer as a culprit. It turned out two of the scanners were interfering with each other. Since it was a mobile set up, I didn't have any options to move the radios or antennas and the scanners didn't have an IF shift like we see in today's equipment. I solved the problem by programming the interfering channels into the same radio.

I still experience occasional "birdies" when driving around today, even though my vehicle has only one scanner and two transceivers. Most of the time, the problem stems from leaking CATV cables nearby.

 

[Golay]

Traveling birdie

Perhaps the original poster is seeing the same thing I see from time to time.
A birdie sounding or static or other noise slowly traveling up the band. I see it most on 2 meters
I can follow it up and out of the band by slowly turning my vfo on the base rig. Don't recall it ever going down.

 

[ScannerSK]

Certain scanners are more prone to "drifting birdies" than others if you can call them that. One of the worst offenders I ever had with this problem was an old Regency scanner. It drove me up the wall. I believe heat sensitive parts are primarily to blame. As temperature changes the frequency drifts.

Most scanners these days do not experience this problem that I am aware of. Usually, it is some other piece of nearby electronic equipment causing the problem. In my truck the after market remote starter creates interference which drifts up and down the VHF spectrum as temperature changes. I just have to re-position the receiver whenever the interference happens to fall on a frequency I monitor.

Shawn

 

[Tim-B]

I'm thinking it could be noise from the many computer cables, tv cables, battery chargers, etc. I have on the same desk where the scanners are. What annoys me is that when I lock out the frequency the same noise finds a new one, then I lock that one out, then it finds a new one, then I lock that one out, then it finds still another, and we go round and round. It's like, "You will not ignore me, human. I'm on a mission to get under your skin today. Just try to catch me if you can." It's like those pesky tiny little flies that come into your house by the hundreds and circle round and round in a little tornado shaped cloud over your sink drain. You kill as many as you can but sometimes they just keep coming back.