Interference or something else?

Trenchdigger

Active member
Location
Vermont
I'm experiencing "something" with my scanner. Not sure if it is interference, or something else, but I am not sure where to start looking. Basically, I hear "Static" across a bunch of frequencies, including frequencies I've previously heard transmissions, such as the aerial refueling and F-35 frequencies.

Here's what I've noticed:
  • Doesn't matter what antenna I use. The bigger the antenna, the more frequencies are impacted.
  • It's a "wide" range, from 0040.500 through 0406.0500.
    • In this range, it seems to be all the military frequencies, rather than civilian.
  • Some frequencies in that range come in clear.
  • When the scanner locks on a frequency, I get nothing but static until I lock out that frequency.
  • If I turn the squelch up to 11, I eliminate the static across all frequencies. If this were rock n' roll, 11 would be great! 🤘
It could be my PV array, acting like a noisy antenna. I doubt it's my WiFi or anything operating over 2.4Ghz.

Not sure it matters, but I also have the FM Notch filter in-line with my antenna. And yes, my RG6 needs to go. I have LMR400 on order. Hoping that helps a bit.
 
A few questions:

1. What scanner?
2. What type of environment do you live in? Suburban, rural, etc. and do you have neighbors in close proximity?
3. Do you have above ground power line construction?
4. Anyone close by using solar panels?
5. Have you tried eliminating interference locally? Any noisy power supplies, etc.
6. Have you tried disconnecting the antenna and seeing if the static remains?
7. Have you, if there's one available, used a portable AM radio as a "static seeker" to see if you can pinpoint where interference might be generated from?
8. Has this been occurring since day one, or is it a recent issue?
9. If recent, what has changed locally that could be a potential cause?

I'll stop there for now. Tracking and eliminating interference is sometimes a considerable task, but in many cases it can be eliminated with some investigation and experimentation.
 
10.) When you get interference, if you look at your "S- meter" on the scanner, is it full scale? Or less than full scale?
If you have an SDS, you can measure it by RSSI, which is even more accurate.
 
A few questions:

1. What scanner?
Uniden BCD325P2
2. What type of environment do you live in? Suburban, rural, etc. and do you have neighbors in close proximity?
Forest, no neighbors worth mentioning (everyone off grid, all others use generator power on weekends only). Closest tower 4 miles away. (ATT, etc)
3. Do you have above ground power line construction?
None. Nearest utility is over 5 miles away as the crow flies.
4. Anyone close by using solar panels?
Me. 28 panels, inverter, etc. Panel optimizers use the 2.4ghz frequency. The panels themselves and wiring may be a problem. I did my best to isolate the roof antenna from the PV array by about 30 feet. Other antennas such as rubber duck are affected inside, and outside the house.
5. Have you tried eliminating interference locally? Any noisy power supplies, etc.
no/none. I'm an idiot as far as that goes ... just surge protectors; nothing else I can think of causing interference, unless it's the above solar/inverter/optimizers. Could appliances, such as "smart" refrigerators or washer/dryers be an issue? They use 2.4ghz so unlikely. The only thing that could be an issue is my ATT signal booster, but that operates above 600MHz, as do the optimizers on my solar system. And my Starlink is north of 900MHz.
6. Have you tried disconnecting the antenna and seeing if the static remains?
Yes, same regardless of antenna. I use the rubber duck, roof, and ground plane with same results, same location.
7. Have you, if there's one available, used a portable AM radio as a "static seeker" to see if you can pinpoint where interference might be generated from?
Oooh, nope! Tell me more. Would a spectrum analyzer be handy? Sounds like a "fun treasure hunt". I don't have any AM radios.
8. Has this been occurring since day one, or is it a recent issue?
From day one. Besides installing a rooftop scanner antenna, nothing has changed.
9. If recent, what has changed locally that could be a potential cause?
None ... same as day one.
I'll stop there for now. Tracking and eliminating interference is sometimes a considerable task, but in many cases it can be eliminated with some investigation and experimentation.
Thank you. A lot to think about. Since this is a "Day One" issue, I'm afraid there may be nothing I can do, but I'll keep poking at it.

I'm betting a lot has to do with my PV array, which is unfortunate; That takes priority over everything since I live off-grid. Other problematic issues may be from local towers, such as the one 4 miles away. Can't do much about that either as far as I know.


10.) When you get interference, if you look at your "S- meter" on the scanner, is it full scale? Or less than full scale?
If you have an SDS, you can measure it by RSSI, which is even more accurate.
I have not done this yet. I'll figure out how to do this and let you know. ... BCD325P2 .... I would love an SDS100, but not in the budget yet.

I do receive clear signal as far as 30 miles away, but only State Police.
 
At night, can you shut everything off related to the solar and storage? I am not familiar with disconnecting solar components as to the ability of a homeowner to do that.
 
As Chris says, that's the experimentation part of things. Unplug potentially noisy power supplies, see if the issue goes away. Solar panel power sources are notorious for these issues.

As to the AM radios not sure what may be available these days for cheap portables but I'm sure Amazon will have varying levels of crap, yet that crap may be good enough to help. I've used them to find power line/transformer noise and to also find the quietest area of my backyard for installation of an active loop antenna I use for HF monitoring.

My gut is that it's the solar panel power source but try unplugging those wall wart supplies (assuming you have them and who doesn't in this day and age) and see if anything changes. Most of them are of the el-cheapo switching supply nature and those are also notorious noise generators.
 
I forgot to add another way that has worked for me.
Find a particularly bad frequency and program that into the scanner. Remove the antenna and walk around the house and even outside. Bring in up to potential sources to see if you can get a reaction. You can also use the ATT function and the squelch to try and isolate the offending device or devices.
 
10.) When you get interference, if you look at your "S- meter" on the scanner, is it full scale? Or less than full scale?
If you have an SDS, you can measure it by RSSI, which is even more accurate.

Less than full scale.

If the scanner is portable try walking away from the house with it and see if your issues go away.

Good idea. I combined this one with CG's suggestion of removing the antenna. The interference remained as I walked around the woods, roughly 300 feet from the cabin. Not sure if that's far enough away to be conclusive, but it does seem to indicate the source is not coming from the cabin.

At night, can you shut everything off related to the solar and storage? I am not familiar with disconnecting solar components as to the ability of a homeowner to do that.
With my system, there's nothing to disconnect without tools. The best I can do is turn off the inverter, but that also cuts all power from the battery bank. When I add a new circuit to my breaker panel, I'll give this a try since I'll have the inverter shutdown anyway.


I don't know if it means anything, but the "interference" seems to be on the military frequencies I have programmed in. Local law enforcement and recreation frequencies don't seem to be impacted. One of the strongest signals is on 296.8000, which is used by NASA. Another strong signal is 41.9000.

Is it possible I'm receiving legit transmissions, though they only come through as static? Some of the signals are really strong (3-4 bars), so I find it hard to believe I'm not hearing any voice. I programmed the scanner using frequencies downloaded from RR.com and uploaded using FreeSCAN.

My gut is that it's the solar panel power source but try unplugging those wall wart supplies (assuming you have them and who doesn't in this day and age) and see if anything changes. Most of them are of the el-cheapo switching supply nature and those are also notorious noise generators.
Yup, no shortage of those here.
 
I don't know if it means anything, but the "interference" seems to be on the military frequencies I have programmed in. Local law enforcement and recreation frequencies don't seem to be impacted. One of the strongest signals is on 296.8000, which is used by NASA. Another strong signal is 41.9000.
FM and AM work quite differently and you will be able to hear interference much more on AM. I believe most of the aircraft channels are AM, while the local law enforcement and recreation is likely FM. That's likely the difference between the two. I would mostly stick with AM mode for testing and experiments.
 
Happy Friday everyone!

Quick update. I'm still poking at things, and keeping a mental list of all the wireless devices around the home, such as weather stations, cameras, etc, and checking to see what frequencies and technology they use for communication. So far so good I haven't found anything obvious causing me grief.

However, I did figure something out and feel like a dummy for not considering it sooner. I realized most scans I was receiving were cutting out every two seconds. You see where this is going? I had Close Call Priority on. When I turned off CC, or went to CC DND ... no more cut outs. So now all scans coming in don't break up anymore, mostly.

Not sure if that is typical when using CC PRI mode or not, but it did the trick for me.

Other frequencies as listed above in the thread are still coming across occasionally as static, so the search continues on those. I think some are legit, just too far away to receive anything but static.

Happy Father's Day to the dads out there.
 
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