Electrical Interference/EMI all around apartment?

[kb7gjy]

Many of the USB chargers are just bad bad bad RF emitters (To the point I think they could be classified as cold war broadband jammers). I had a dual port charger that once it was plugged in would "warm up" in about 5 minutes and would cause a S7 noise floor on everything from 160 meters to 1.2 GHz (That was with an outside antenna). This was after I had it for several months. Tracking it down was difficult due to the "warm up time" as when power was applied it would just slowly increase.

As others have said, the usual suspects;
Anything cheap that plugs in (USB chargers, wall warts, etc)
LED lights
Other radios
Also don't rule out things outside the home, (Street light that is acting up or was just replaced, A neighbor that, during the lock-down. took up learning to arc weld (for the record, that was some of the worst CW I have ever tried to decode LOL).
Also being in an apartment, don't forget that maybe someone else might have something plugged in that is causing the RFI and they don't have a clue.

Hope this helps

 

[RedPenguin]

I don't know if this could possibly do it or not.

There is a Ch 24 in my market also, but it's transmitter is in the next county and I never "seen" this signal until this morning.

It keeps cutting in and out like 59% signal at best, but wonder if it could be causing some fun to Ch 22. You see it then it cuts out, then it comes back, over and over.

Doesn't seem like it should though as others in the market claim they don't have them interfer with each other.

 

[jim202]

Let me just throw this into the equation. Not trying to hijack the thread, but bring up another area that can cause issues. I have found that the electrical ground rod below the power meter can cause a high resistance to the ground system if it is say 10 years old or more. Found this out after my house took a lightning strike in a tree not too far from the house. Had all sorts of damage done in the house to electronics and the pre stressed cable foundation slab.

Working for a cellular company, I brought home an earth resistance tester. Killed the power to the house with the main breaker. Then lifted the ground wire going to the ground rod. Put the meter on the ground rod while it was disconnected to the ground wire from the meter pan. Found out the resistance was like 500 Ohms. Picked up a new ground rod and drove it into the ground. Measured the new ground and now had like 5 Ohms resistance. So connected the ground wire up to the new ground rod and put the house main breaker back on.

High resistance in your electrical system ground can cause all sorts of strange noise problems. Switching power supplies are a common problem.

As others have said, you could be having an image problem from near by transmitters. This is a hard issue to determine without putting in line filter traps for the exact frequency that could be causing a problem.

At least you have narrowed down some of your issues. Good luck on tracking down what's left.

Jim

 

[RedPenguin]

Thanks for all the replies.

The thing I don't really know how to test for the Ch 22 issue is if it's actually interference or not.

It seems every once in a while, like a burst just blasts away the signal for a few seconds, then it fixes itself.

I keep checking all possible interference sources but only found that USB charger so far.

Yet, on another forum I was told by a user who has two HC2 Holdings LPTV Stations (in Missouri) that both do very similar to my HC2 Ch 22, where every so many minutes, signal quality goes crazy then fixes itself. He thinks the station's Internet Feeds of the channels aren't synced well.

Yet some viewers in my area tell me they get the station just fine, but I did notice if you are just casually viewing, I don't think you'd notice these bursts as only little pieces of the screen pixelate or break up.

I just am not sure how to easily test to prove for a fact it's my actual reception issue or something is going on at the actual station level.

 

[mmckenna]

Thanks for all the replies.

The thing I don't really know how to test for the Ch 22 issue is if it's actually interference or not.

It seems every once in a while, like a burst just blasts away the signal for a few seconds, then it fixes itself.

I keep checking all possible interference sources but only found that USB charger so far.

Yet, on another forum I was told by a user who has two HC2 Holdings LPTV Stations (in Missouri) that both do very similar to my HC2 Ch 22, where every so many minutes, signal quality goes crazy then fixes itself. He thinks the station's Internet Feeds of the channels aren't synced well.

Yet some viewers in my area tell me they get the station just fine, but I did notice if you are just casually viewing, I don't think you'd notice these bursts as only little pieces of the screen pixelate or break up.

I just am not sure how to easily test to prove for a fact it's my actual reception issue or something is going on at the actual station level.

Be cautious not to get sidetracked on this.
The TV issues may or may not be related. Interference can certainly cause what you are seeing, but so can low signal levels. I've got a few stations near me that come and go sporadically depending on weather.
You could have a separate issue with your TV antenna, and that might be adding to the confusion.

Also, while your USB charger may have been part of the issue, so could others in your area. Sounds like you might be in an apartment or condominium complex, so it's entirely possible. Since electrical wiring can act like a big antenna, something in a neighbors house, condo or apartment might be causing some of it. I know my son has a cigarette lighter USB adapter for his Nintendo Switch that will knock out the tire pressure monitoring system in my wife's car.

Usually tracking down issues like this takes a lot of trial and error. You've been given some great advice by others, so work through it methodically. Maybe start by taking your scanners away from your home and see what happens. See if this is a wider area issue, or something very local to you. If it is very local and coming from one of your neighbors, you are going to have a hard time convincing them to work with you on this stuff unless you are on really good terms with them.

 

[RedPenguin]

Well, I am at least making some progress.

I swapped out the scanner's CATV amp for a different one that I had around that has no splitter built in.

That has finally got the further out stations to receieve much more normal.

 

[dlwtrunked]

...
Anyway, I noticed lately if I turn an incandescent lamp on/off in the same room or even in the downstairs living room underneath a small fan, it can disrupt reception.
...
[/QUOTE]

Is it on a light dimmer circuit? Those can create horrible interference. Are you sure it is an incandescent not a CFL or LED (some) can cause problems. but you said "on/off"--did you just mean "on". And a touch lamp will almost always be a problem.

 

[RedPenguin]

...
Anyway, I noticed lately if I turn an incandescent lamp on/off in the same room or even in the downstairs living room underneath a small fan, it can disrupt reception.
...


Is it on a light dimmer circuit? Those can create horrible interference. Are you sure it is an incandescent not a CFL or LED (some) can cause problems. but you said "on/off"--did you just mean "on". And a touch lamp will almost always be a problem.

Well it was rather weird.

It's a wall lamp that has an older incandescent 3-way in and if you "cycled" through the switch a few times, it would cause immediate interference.

Same with a 5W nightlight bulb. You'd flick the switch a few times and instant interference.

Yet strangely, even though those two lights were in the room with the antenna but the USB charger was downstairs yet underneath the room with the antennas, the interference from the lights immediately stopped once it was replaced with two single USB chargers.

All I can figure is turning lights off and on caused a small disruption in power and caused the USB adapter to throw more noise?

 

[RedPenguin]

Well I think I finally solved the scanner side of things.

I just ripped apart the entire feed wires setup and checked the connections on the dipole.

I also rewired the nearby power strips as the wires got frustrating through occasionally rearranging or checking stuff.

Doing all of that seems to have cleared up reception a lot.

The TV issue is still there so not sure that issue is really connected or not.

It did seem like that USB adapter did affect both though as way better reception on all scanners it seems like now.

It seems the USB was affecting 453.150 a lot as that receives way more often now.

 

[RedPenguin]

I seem to making some progress at least.

I removed my USB adapter for my BC75XLT and it seems like the TV is going longer without errors.

I am going to keep checking some of the other adapters to see if I can get anywhere.

 

[RedPenguin]

Well, I guess there is no end at all to how much noisy stuff I have.

I just found a wall-wart for an older cordless phone that does just like the NOAA Radio. If you plug in/unplug a few times, the TV goes crazy.

Not sure what I will do with all the noisy stuff as I wasn't really expecting to "retire" them, at least the NOAA Radio.

 

[RedPenguin]

You know I just thought of something and maybe somebody would have a way to figure out if this is the reason.

I started thinking being that I am getting blips from the next county over's TV station at Ch 24, if this situation is possible like a person on another forum suggested.

The towers right by me, 2.21 miles away have Ch 22 LP & Ch 34 full power.

Yet in the next county with Ch 24, the Ch 34 from my area in the same transmitter location has a translator/repeater on Ch 22 as well, which they agreed to move to Ch 33 but it's taking a while.

Anyway even though the 22 translator is way less power like 7kWh vs almost 40kWh for Ch 24, is it possible that I am at times getting that signal in to my setup and destroying my local Ch 22?

 

[RedPenguin]

I was going to edit the above but it was too late.

I bet it is the "phantom" Ch 22 interfering with my local Ch 22.

I watched on my HDHomeRun Ch 24 and it shows up for 1-2 seconds then disappears in bursts basically. It can take minutes between these appearances. I assume it's probably doing the same with the other 22 but I can't see it as my local one is there.

To me that lines up exactly with my issue, basically excellent signal with short bursts of errors.

 

[bob550]

Given the varied and inconsistent nature of the RFI, I would suggest you have a qualified electrician check your house ground system. They may as well check your electrical panel at the same time.

 

[RedPenguin]

Well some updates finally. I was going to give them earlier but got busy for a little while.

Anyway, I seem to finally have the scanners in working order completely.

It seems re-wiring all the electrical plugs to the scanners and a few other items nearby helped.

But it seems like part of the feed line from the dipole somehow failed (I'm thinking one of the connectors) and I ran a new wire and that fixed the reception with the further away stations.

I did get further updates on the TV interference issue though.

I spoke with some of the folks over at SiliconDust & AVSForum and they believe based on my equipment readings/experiments, that it is most likely the Ch 22 Translator from the local Full Power station interfering at times with my local Ch 22.

Strangely according to SiliconDust, the Translator being in the same market should by no means be on RF Ch 22 when a Class A LPTV is assigned to it. They said the Class A LPTV by rights should be forcing the translator off the air as that's clearly interference. The FP station said they expect to have it changed to RF Ch 33 by the end of June.

 

[RedPenguin]

Ok, this may sound crazy but I have no real way to explain this other than maybe some better atmospheric conditions or something.

In my area, the gas utility a few months ago dug up the road to put in new pipes, replacing the old metal I believe with newer PVC ones. They left just leaving a bump in the road.

They finally showed back up I guess to finish up and it seems like eventually repave the road.

I just find it odd that since they've been working for a little while my reception went way up without me touching a thing.

Do utility crews sometimes put stuff in the work area that emits EFI?

 

[mmckenna]

Do utility crews sometimes put stuff in the work area that emits EFI?

Depends on what they are doing. Some utilities use tracer signals for finding cable/pipelines. A long time ago I worked for a fiber optic company and we had transmitters in our facilities that connected to a tracer wire that ran along with the fiber optic cable. The signal injected was extremely low frequency, down in the double/triple digit KHz range. The wire following the fiber would radiate that signal and allow us to use tracing devices that would look for that signal.

Pipeline companies sometimes do the same thing.

But again, it's super low frequency stuff, and not likely to interfere with any of your equipment.

If they were arc welding pipelines, that can radiate some RFI.
Noisy ignition systems on construction equipment can generate a lot of RFI.

 

[RedPenguin]

Depends on what they are doing. Some utilities use tracer signals for finding cable/pipelines. A long time ago I worked for a fiber optic company and we had transmitters in our facilities that connected to a tracer wire that ran along with the fiber optic cable. The signal injected was extremely low frequency, down in the double/triple digit KHz range. The wire following the fiber would radiate that signal and allow us to use tracing devices that would look for that signal.

Pipeline companies sometimes do the same thing.

But again, it's super low frequency stuff, and not likely to interfere with any of your equipment.

If they were arc welding pipelines, that can radiate some RFI.
Noisy ignition systems on construction equipment can generate a lot of RFI.

Thanks again, I just thought it was weird how the construction crew returns and all the sudden most of the reception is now crystal clear even though I didn't touch a thing.

I even seem to be getting a hard-to-get signal from a local Campus PD coming in crystal clear.

 

[RFI-EMI-GUY]

Ok, this may sound crazy but I have no real way to explain this other than maybe some better atmospheric conditions or something.

In my area, the gas utility a few months ago dug up the road to put in new pipes, replacing the old metal I believe with newer PVC ones. They left just leaving a bump in the road.

They finally showed back up I guess to finish up and it seems like eventually repave the road.

I just find it odd that since they've been working for a little while my reception went way up without me touching a thing.

Do utility crews sometimes put stuff in the work area that emits EFI?

Normally your electrical utility grounding system should never touch the metal gas pipes. However, appliances inside the home might complete a circuit and a water pipe and gas pipe might rub together.

If it were me, 1) I would locate the ground rod for your home and add a second 8 ft one a couple feet away and bond the new to the old. Never remove the wire from the old one. Clamp new wire with new brass clamp. 2) you need to isolate your antenna system by putting it outside your home. 3. Ground your radios and lightning protection to that new ground system,

 

[mmckenna]

Thanks again, I just thought it was weird how the construction crew returns and all the sudden most of the reception is now crystal clear even though I didn't touch a thing.

I even seem to be getting a hard-to-get signal from a local Campus PD coming in crystal clear.

I think I misunderstood your post. I was thinking your issues returned.

Yeah, I'd agree with RFI-EMI-GUY on this one. While gas pipes shouldn't be used as a ground, the often become part of the ground system. If your ground in your home is funky, then it may be trying to use the gas pipes. If pipes were corroded and they replaced them with new conductive pipes, that could improve your ground.