Power Line Noise?

emsflyer84

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Hey guys, first of all, let me apologize as this is probably my 5th post regarding my reception problems with a base scanner set up at my house. I've gotten lots of good info and tried lots of things, but haven't been able to resolve the issue. Then today I found an old post from someone having a similar issue as me. He posted a recording of the interference he was getting. It sounds EXACTLY like what I am hearing on weaker signals. That interference was tracked down to a transformer in front of the building he was in. Power line noise! The one thing I hadn't really considered but would explain all the issues I'm having. If there is an issue with a line or transformer in front of my house, it would explain why I have the same issues regardless of scanner / antenna combo, coax length, connectors, inside or outside my house, etc.... And it would explain why I still had the issues even after turning off the main power breaker in my house and running the scanner on batteries. It would also explain why reception improves just up the road from my house.

Here is my question. Can power line noise also cause a loss of reception? I know it will cause interference and noise, but my issue also includes a loss of reception of signals I used to get fairly well. For example, there are signals I used to get clearly. Then for a while, maybe a month, I would get those signals clearly sometimes, then not at all other times. Now I almost never get them at all. Like the power line issue was intermittent at first.

Quick tip: Once in a while the signals that are scratchy and noisy come in crystal clear all of a sudden, like someone threw a switch. Then just as quickly, the noise would be back.

Another tip, the issues I'm having are in the VHF High public safety range (150's). Anything I scan in the 400's seems to be ok. I don't scan anything lower then the VHF High range. Thanks again.

Just curious if I might be on the right track here before I start trying to track down the source. Thanks guys, the help is much appreciated.
 
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emsflyer84

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If the noise is stronger than the reception of the other stations, then yes, it could keep you from hearing them
Makes sense. Seems like that’s the case. The signals that are farthest away don’t come in at all, ones that are slightly closer and stronger come in but with the power line noise. The strong very close signals come in with no interference.
 

cavmedic

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Makes sense. Seems like that’s the case. The signals that are farthest away don’t come in at all, ones that are slightly closer and stronger come in but with the power line noise. The strong very close signals come in with no interference.
Get an am transistor radio and walk around the hood. Sure you will find it easily if its on the line
 

emsflyer84

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Thanks, I’m not sure about how to do this really. I have a small AM/FM radio with telescoping antenna I can use but not sure if that would work? If it would, what would I set the radio on? Thanks in advance.
 

krokus

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Thanks, I’m not sure about how to do this really. I have a small AM/FM radio with telescoping antenna I can use but not sure if that would work? If it would, what would I set the radio on? Thanks in advance.
Any weaker station, that allows the noise through. It sounds like you have already done this, in a way, since you mentioned that your reception improved a block away.
 

emsflyer84

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I have, I’ve done lots of experimentation here. Just up the road in either direction reception improves. And it seems to be slightly worse standing on my roof then at ground level at my house, but not by much. Maybe because I’m at eye level with the power lines? I’m pretty sure that if it is power line noise, it’s one of the poles right in front of my house. Also, they are doing utility work now and putting new poles in as we speak. Maybe the problem will fix itself once they transfer the utilities to the new poles...
 

lenk911

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There is a world wide study of man made noise up into the VHF band. Besides the electrical system interference described above, look at your own computers, in-line power supplies, and outlet power modules (wall warts). You may be generating your own troubles. I have measured 25 db interference from energy saving lighting in the 154 MHZ band. If you can power your receiver from a battery, kill the power to your whole facility (home) first. Then look to the outside world.
 

w2xq

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Hey guys, first of all, let me apologize as this is probably my 5th post regarding my reception problems with a base scanner set up at my house.

Another tip, the issues I'm having are in the VHF High public safety range (150's). Anything I scan in the 400's seems to be ok. I don't scan anything lower then the VHF High range. Thanks again.

Just curious if I might be on the right track here before I start trying to track down the source. Thanks guys, the help is much appreciated.
Since.the power transformer appears to be the problem, ask your electrical utility company to investigate. I suggest ask rather than demand... you know the drill.

Re VHF reception changing, distant VHF station reception can be affected by weather conditions, notably with temperature inversions that occur in the spring and fall. Weather fronts with a air masses of markedly different temperatures can cause signals to propagate along the front; look at a weather map to see if a front over you extends into the area you are receiving better than average signals.

If you are near the coast, you undoubtedly will have better signals from stations north and south of you along the coast. Land and water heat and cool at different rates, particularly noticeable at sunrise.

The RR wiki probably has more to say on propagation. HTH. YMMV.
 

a417

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Hey all, quick update. Power company is out in front of the house transferring the utilities to the new poles they installed a few weeks ago. As of right now, interference is gone and reception is greatly improved! We’ll see if it continues.
New insulators, new connectors, waterproofing, etc...
 

Grondoline

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Glad your problem went away. I was going to say look at the poles nearest your house and see they if there's a capacitor bank on one of them. They are remotely switched on and off the line according to time of day and other conditions.
 

emsflyer84

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And... I spoke too soon. The noise is back. It’s like they have something turned off for a couple days and the noise went away. They are actively working on the utilities right in the problem area though, so I’ll ride it out and see where we’re at when they’re done.
 

BC_Scan

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The transformer where the hydro is clamped to the drop that feeds the house is possibly the culprit , when the clamps or (c-lok) loosen over time they induce or bring on this noise, try your expirement with your am/fm batt operated radio walk around in vicinity of transformer even if it is multiple pole spans from your house , than you can demand hydro remedies this. I know this was used by an engineer to pinpoint noise interfering with an airband txer for a small float plane local company.
On another note what about that hydro emi/rfi clamp that they install at circuit breaker panel in house. Schneider Electric and others make these
 

emsflyer84

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The transformer where the hydro is clamped to the drop that feeds the house is possibly the culprit , when the clamps or (c-lok) loosen over time they induce or bring on this noise, try your expirement with your am/fm batt operated radio walk around in vicinity of transformer even if it is multiple pole spans from your house , than you can demand hydro remedies this. I know this was used by an engineer to pinpoint noise interfering with an airband txer for a small float plane local company.
On another note what about that hydro emi/rfi clamp that they install at circuit breaker panel in house. Schneider Electric and others make these
Thanks. I've done a non-scientific experiment by tuning my car radio to a dead AM station and driving up and down the road. As soon as I get to the first pole in front of my house, the noise level coming through my radio multiplies by at least three times. It continues while I drive parallel to the span of wire between the first pole and the next pole, which is also basically in front of my house. Shortly after passing the second pole, the noise starts to drop down significantly. There are small transformers on each of these poles and a drop to my house on the first, a drop to the neighbors house on the second. I'm sure the issue is somewhere in this span. The strange part is, while they were working just up the street the other day the noise was totally gone for almost two full days. Then the next evening it was back. Well after they were done working for the day. So it's almost like the noise is coming from something that can be turned off and on remotely.
 

krokus

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Thanks. I've done a non-scientific experiment by tuning my car radio to a dead AM station and driving up and down the road. As soon as I get to the first pole in front of my house, the noise level coming through my radio multiplies by at least three times. It continues while I drive parallel to the span of wire between the first pole and the next pole, which is also basically in front of my house. Shortly after passing the second pole, the noise starts to drop down significantly. There are small transformers on each of these poles and a drop to my house on the first, a drop to the neighbors house on the second. I'm sure the issue is somewhere in this span. The strange part is, while they were working just up the street the other day the noise was totally gone for almost two full days. Then the next evening it was back. Well after they were done working for the day. So it's almost like the noise is coming from something that can be turned off and on remotely.
How has the weather been, over those days? Any snow or rain, that might have dried out? Winds that may have shifted a connection?
 

emsflyer84

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The days it worked well we’re dry and breezy. But over the past several months that I’ve had the issue we’ve had all kinds of weather that didn’t seem to make a difference.
 
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