Strange background noise on almost all frequencies?

[smlegg]

Hi, i’m in Central Scotland, and i’ve started radio scanning with the Uniden EZI33XLT and a small external airband antenna. I’m getting weird background noise on all frequencies, especially on 119.1 (Glasgow Approach) - it’s like a very distorted constant transmission which sounds like people talking or music playing. I’ve tried turning the squelch all the way up but i’m still getting the background noise making it hard to use the scanner - since it it just stopping on every frequency. Any help would be great
Thanks

 

[KEWB-N1EXA]

AM/MW Broadcast station or HF near you you may need a AM Band Broadcast Trap added before your radio antenna input.
This also could be a Local FM Band Transmitter too... Your going to have an experiment and research your issue.
Are there any big transmitters near you even miles away?

There some affordable ones (traps) on ebay you can try out. I have the same issue here in the USA with local FM Broadcast stations on the
Air band and AM station on some HF frequencies.

Pete N1EXA

 

[bb911]

In addition to the above, does Scotland have any citizen or other use AM bands near 25 (+/-) Mhz? Years ago when CB radios (around 27 Mhz) were a fad in the US, the FCC was kept busy tracking down some users who were interfering with the air band in some areas. (High power linear amps were used by some).

BTW, just for fun, to find potential villains in the FM broadcast band, remove your antenna and manually 'scan' the FM band with no antenna. You may hear a weak signal(s) from high power transmitters. Repeat the above while touching the antenna input with the metal tip of a plastic pen (a pen without a spring, or remove the spring from a pen). I live in So California and I can hear some FM broadcast stations loud and clear with a pen tip "antenna".

 

[smlegg]

AM/MW Broadcast station or HF near you you may need a AM Band Broadcast Trap added before your radio antenna input.
This also could be a Local FM Band Transmitter too... Your going to have an experiment and research your issue.
Are there any big transmitters near you even miles away?

There some affordable ones (traps) on ebay you can try out. I have the same issue here in the USA with local FM Broadcast stations on the
Air band and AM station on some HF frequencies.

Pete N1EXA

Hi, there’s an FM and TV transmitter about 13 miles away, would that interfere? If so, what do you recommend i should get? Thanks

 

[krokus]

Hi, there’s an FM and TV transmitter about 13 miles away, would that interfere? If so, what do you recommend i should get? Thanks

Unlikely that they would be the problem, at 13 miles distant. Less than five miles, would be more likely.

Is there any discernable speech in the noise? Can you match it to an analog radio broadcast?

 

[KEWB-N1EXA]

Hi, there’s an FM and TV transmitter about 13 miles away, would that interfere? If so, what do you recommend i should get? Thanks

You can try a 88-108Mhz FM Band Rejection Filter. They usually come with SMA connectors but you can get adaptors for BNC or PL-259 Connectors.
But 13 miles away seems pretty far are you sure there are no AM/MW transmitter towers near you?

pete N1EXA

 

[ka3jjz]

Yes, I would do a little digging before throwing filters in the line. It could even be a local MW transmitter that is overloading you. A simple search using any MW radio and matching the distortion with the MW radio may well bring results. In fact the simpler the MW radio the better - it would likely be a pretty strong signal so it should stand out like the proverbial sore thumb. It's not completely out of the question that the station has a transmitter fault, though you would think that would be cleared up pretty fast...Mike

 

[smlegg]

Unlikely that they would be the problem, at 13 miles distant. Less than five miles, would be more likely.

Is there any discernable speech in the noise? Can you match it to an analog radio broadcast?

One time i was able to match the speech to a radio station about 15mhz lower, but that’s about it- the rest just sounds like constant background static

 

[ka3jjz]

This definitely smacks of overloading or maybe a dirty transmitter - especially since you had heard it 15 Mhz lower. Time for some concerted homework...Mike

 

[smlegg]

i should add - this has just started since i got a new antenna, could this be the problem and is there any way i could fix it?

 

[wtp]

get rid of the new antenna ?

 

[krokus]

i should add - this has just started since i got a new antenna, could this be the problem and is there any way i could fix it?

That would indicate overload. A filter for the broadcast band in question could cure the problem.

 

[smlegg]

That would indicate overload. A filter for the broadcast band in question could cure the problem.

What filter do you recommend?

 

[Ubbe]

What filter do you recommend?

We have done some measurements and given advice in this thread: FM bandstop filter comparison

/Ubbe

 

[smlegg]

We have done some measurements and given advice in this thread: FM bandstop filter comparison

/Ubbe

Thank you!