Pulsed interference

[Gumball928]

I have a Uniden BCT-15X and have it programmed for local county Fire, Police, Rescue, located in NW Oregon.
The antenna is a "discone type" on a 8 ft pole above my house.
From some transmissions, there is a steady "pop-pop-pop" at a rate of 2-3 per second.
From other transmissions in the county, that interference is not there.
This has recently begun, about 3 months ago (in conjunction with colder weather ???)
I would appreciate any suggestions . . . .

 

[tvengr]

If you have another scanner, turn it off. One scanner scanning can interfere with another.

 

[ind224]

Perhaps grow lights.

 

[RFI-EMI-GUY]

is the priority scan mode turned on?

 

[rf_patriot200]

I have a Uniden BCT-15X and have it programmed for local county Fire, Police, Rescue, located in NW Oregon.
The antenna is a "discone type" on a 8 ft pole above my house.
From some transmissions, there is a steady "pop-pop-pop" at a rate of 2-3 per second.
From other transmissions in the county, that interference is not there.
This has recently begun, about 3 months ago (in conjunction with colder weather ???)
I would appreciate any suggestions . . . .

Could you be picking up mobile extenders ? These will make a similar sound as they re-transmit. Is the Weather Alert on your 15x turned on? That might do it too.

 

[Whiskey3JMC]

After you make sure priorities and close call are turned off, disconnect from the discone & stick on a rubber ducky. Is the "popping" still evident? If yes, it's likely a source of RFI inside your house

 

[mark40]

One scanner scanning can interfere with another.

Very plausible, I've experienced this.

 

[ecps92]

I have a Uniden BCT-15X and have it programmed for local county Fire, Police, Rescue, located in NW Oregon.
The antenna is a "discone type" on a 8 ft pole above my house.
From some transmissions, there is a steady "pop-pop-pop" at a rate of 2-3 per second.
From other transmissions in the county, that interference is not there.
This has recently begun, about 3 months ago (in conjunction with colder weather ???)
I would appreciate any suggestions . . . .

What specific Frequency is being interfered with ?

 

[Gumball928]

THANK YOU for all the replies. I do appreciate the advice, as I am very inexperienced in this.

- I tried the "rubber ducky", no change
- we do not have grow lights
- weather alerts not on
- priority scan not on
- around 450 mhz
.
But, I do have 2 of BC-350 scanners in close proximity. I tried turning them off, and SCHAZZAM, the interference disappeared.

So, what causes the interference ?? What can I do to fix this problem ?? I would like to keep using all 3 scanners if possible "?

.

 

[rf_patriot200]

THANK YOU for all the replies. I do appreciate the advice, as I am very inexperienced in this.

- I tried the "rubber ducky", no change
- we do not have grow lights
- weather alerts not on
- priority scan not on
- around 450 mhz
.
But, I do have 2 of BC-350 scanners in close proximity. I tried turning them off, and SCHAZZAM, the interference disappeared.

So, what causes the interference ?? What can I do to fix this problem ?? I would like to keep using all 3 scanners if possible "?

.

I remember some of the Older Bearcat scanners, like my old BC 300 and 220 and the I.F. section in those created interference on other receivers, so Separating those to another room cured the problem.

 

[wtp]

to receive a signal and let you listen to it the radio uses an intermediate signal that it generates by itself.
if another radio is close by and on some certain frequencies they can be picked up.
this might give you the idea.
set the 350 to 460.0 and try setting 449.2 in the other one
if nothing happens, try 470.8
for radio shack scanners it is/was 10.7
and for bearcat it is/was 10.8 for the I.F.'s
another thing might be to program all the 400 something into only one radio, and other bands in the others.
what i do is put the low band freqs into a radio with a long antenna
the 400's in one with a 6 inch antenna and the 800 in one with an 800 Mhz antenna.

 

[tvengr]

But, I do have 2 of BC-350 scanners in close proximity. I tried turning them off, and SCHAZZAM, the interference disappeared.

So, what causes the interference ?? What can I do to fix this problem ?? I would like to keep using all 3 scanners if possible "?

Are the scanners fed from a common antenna. The local oscillator can radiate a signal from one scanner into another. Uniden scanners generally use a 10.8 MHz IF. You may be also picking up the IF from adjacent scanners. Try separating the scanners. If usng a common antenna, you need a splitter or multi-coupler with more isolation between the scanners. Also try connecting the scanner cases together with a heavy ground wire and connect that to a good ground such as a water pipe.

 

[ecps92]

Are the scanners fed from a common antenna. The local oscillator can radiate a signal from one scanner into another. Uniden scanners generally use a 10.8 MHz IF. You may be also picking up the IF from adjacent scanners. Try separating the scanners. If usng a common antenna, you need a splitter or multi-coupler with more isolation between the scanners. Also try connecting the scanner cases together with a heavy ground wire and connect that to a good ground such as a water pipe.

Even having them in the same house, can generate enough RF from the Oscillators

I remember 50+ yrs ago driving my younger brother crazy by tuning my AM Radio to be enough to cause his local AM station to mute-out
Fun times, knowing the math.

In Metro Boston and likely other T-Band areas, we all had to do the math to remove 460 band frequencies from our 483 channels, by listening to the 505-507 range - worked wonders and no loss of reception

 

[tvengr]

Even having them in the same house, can generate enough RF from the Oscillators

I have located downed RC model aircraft in wooded areas by homing in on the local oscillator frequency in the receiver using a directional antenna. An oscillator is a low power transmitter.

 

[wtp]

after hurricane charlie a neighbor was using a little cheap WT.
he was all over the neighborhood help folks and left his little two way somewhere.
i used a twin of his to find the LO freq for the freq he had set it to it took almost two whole minutes to find his.
it was next door behind a stump, that he had cut the tree down.

 

[Kingscup]

I had an interference problem that sounds similar to the OP. It turns out it was my wireless router. Luckily, it only happened on one frequency and that frequency was only used for larger incidents so it wasn't used too often. I turned off the 2.4 Ghz mode and only used the 5 GHz and that worked for me.

 

[Dubberdog]

I've had a mobile phone make that type of noise when it's sitting near the scanner, when moved away from the scanner it stops. The noise on the scanner that is

 

[RFI-EMI-GUY]

When I had two crystal controlled scanners, 8 channels each I used to get that silly LO interference between them. Its a pretty sharp click with crystal radios.

 

[RFI-EMI-GUY]

after hurricane charlie a neighbor was using a little cheap WT.
he was all over the neighborhood help folks and left his little two way somewhere.
i used a twin of his to find the LO freq for the freq he had set it to it took almost two whole minutes to find his.
it was next door behind a stump, that he had cut the tree down.

He must have thought you were a wizard for doing that.

I once helped the gal next door to get into her house by picking her door lock. Not sure if the look she gave was creepy dismay that I could do that or that she was sad not to spend time at my house waiting for the key. Probably the former.

 

[wtp]

to RFI guy,
he kind of expected it from me.
and on the other note.
last week the step son called to see if i had time to pick, a female friend of his, front door lock.
someone else got it just as i got there.
i had close to 10 years picking locks at a hardware store.
but now i have/use makeshift tools.