Saving AM Radio

[kwthom]

What do most people care more about, their fancy devices or AM. Probably a double edged sword. As AM gets worse they move more to those devices for listening.

Yet, which device does *more* - a simple AM/FM radio, or a cell phone with data service?

A few million of us who have a small amount of technological savvy have moved on to other ways of consuming audio, a common theme in these sorts of threads.

Sure, as has been pointed out here, and in a lot of other threads, the fallacies of maintaining the "AM Way of Life" is dying.

Primarily because the bulk of the audience has also passed on.

 

[cc333]

Correct. Stuff associated with your computer or TV -- even the humble wall wart -- can put out all sorts of audio garbage.

The other day, I discovered that even an extension cord can cause trouble.

I was carrying my radio through the house, looking for potential noise sources, and found that the garage was so bad that nothing got through.

I wandered around, and discovered that it was worst over by the garage door, near an outlet where the sprinkler timer is plugged in. I unplugged its wall wart, and there was no change.

Then I noticed the extension cord was plugged in to the same outlet.

Figuring maybe there was a battery charger or something plugged into the other end, I unplugged it from the wall. Imagine my amazement when the noise disappeared almost completely!

I checked the other end of the cord, and nothing was plugged into it. The cord itself was causing all that noise!

How can this be?!

c

 

[K.M. Richards]

Then I noticed the extension cord was plugged in to the same outlet.

Figuring maybe there was a battery charger or something plugged into the other end, I unplugged it from the wall. Imagine my amazement when the noise disappeared almost completely!

I checked the other end of the cord, and nothing was plugged into it. The cord itself was causing all that noise!

How can this be?!

The simple engineering-based answer is that the cord was acting as an unintentional radiator.

 

[Don CT]

The other day, I discovered that even an extension cord can cause trouble.

I was carrying my radio through the house, looking for potential noise sources, and found that the garage was so bad that nothing got through.

I wandered around, and discovered that it was worst over by the garage door, near an outlet where the sprinkler timer is plugged in. I unplugged its wall wart, and there was no change.

Then I noticed the extension cord was plugged in to the same outlet.

Figuring maybe there was a battery charger or something plugged into the other end, I unplugged it from the wall. Imagine my amazement when the noise disappeared almost completely!

I checked the other end of the cord, and nothing was plugged into it. The cord itself was causing all that noise!

How can this be?!

c

is the problem that the signals are underpowered or would that not matter at this point. Could radio overcome the noise floor or is that cat out of the bag.

 

[boombox4]

The other day, I discovered that even an extension cord can cause trouble.

I was carrying my radio through the house, looking for potential noise sources, and found that the garage was so bad that nothing got through.

I wandered around, and discovered that it was worst over by the garage door, near an outlet where the sprinkler timer is plugged in. I unplugged its wall wart, and there was no change.

Then I noticed the extension cord was plugged in to the same outlet.

Figuring maybe there was a battery charger or something plugged into the other end, I unplugged it from the wall. Imagine my amazement when the noise disappeared almost completely!

I checked the other end of the cord, and nothing was plugged into it. The cord itself was causing all that noise!

How can this be?!

c

Just like wall outlets can go bad with lots and lots of use, the socketed end of your extension cord is technically an outlet, and I suppose they can go bad, either from use, or just being cheaply made. Although, you'd probably have felt some heat on the cord if that were the case. If it was a long extension, KM Richards' suggestion may indeed be the case.

 

[boombox4]

Might be the utility, might be all of the horrible electronic devices in your home and in the homes of your neighbors.

One would think there would be more of those in a large city like San Antonio, though, than a small city in NW Arkansas.

 

[ajaynejr]

Some other electrical device was putting electrical noise into the power lines (probably via its own power cord plugged in) and the extension cord allowed that interfering signal to get close to the radio.

 

[K.M. Richards]

is the problem that the signals are underpowered or would that not matter at this point. Could radio overcome the noise floor or is that cat out of the bag.

That is a factor ... to some degree. A station with higher signal strength at any given location will override the noise floor to whatever extent is possible. I doubt that the electrical noise could be completely overridden, but a decent signal would still be reasonably listenable.

Cases in point, from my residence in the San Fernando Valley of Los Angeles: I am roughly 40 miles away from the KFI and KNX transmitter sites, each of which is 50kW non-directional. Even with fluorescent and LED lights and my computer on (plus all of the wall warts for various devices around the house) I don't find the signals from either to be degraded enough to preclude listening if I want to. In fact, KNX-FM has a worse signal than the AM, and I am only about 25 miles from Mount Wilson.

On the other hand, I am only four miles from KMZT, with 20kW days and there's enough static to make it unpleasant to listen much of the time (but not always). On its nighttime 7.5kW it's practically buried in the noise here.

None of the closest stations with even lower power than KMZT are clearly receivable here.

So yes, it can be a factor, depending on where you are relative to a station's transmitter, but not universally.

 

[cc333]

The simple engineering-based answer is that the cord was acting as an unintentional radiator.

Just like wall outlets can go bad with lots and lots of use, the socketed end of your extension cord is technically an outlet, and I suppose they can go bad, either from use, or just being cheaply made. Although, you'd probably have felt some heat on the cord if that were the case. If it was a long extension, KM Richards' suggestion may indeed be the case.

Indeed.

What I suspect is that something in the house is putting noise into the AC wiring, and having that cord plugged in allowed it to radiate somehow.

Either that, or, there's some kind of external noise somewhere (I suspect the power transformer serving my neighbor by the garage, as the noise seemed worst when I aimed my radio in that general direction) and this cord acted as an antenna, receiving that noise and radiating it throughout the house.

Whatever the cause, I'm glad the apparent "fix" was so simple!

c

 

[K.M. Richards]

What I suspect is that something in the house is putting noise into the AC wiring, and having that cord plugged in allowed it to radiate somehow.

Either that, or, there's some kind of external noise somewhere (I suspect the power transformer serving my neighbor by the garage, as the noise seemed worst when I aimed my radio in that general direction) and this cord acted as an antenna, receiving that noise and radiating it throughout the house.

All valid possibilities. I have been told by many broadcast engineers that those wall warts are very cheaply designed and made and are frequently the culprit in terms of electrical noise. So "something in the house" could indeed be any of those powering any of your devices. Even your phone charger can emit spurious noise.

The power transformer next door is pretty much the same, only a lot bigger.

 

[Mark Roberts]

The power transformer next door is pretty much the same, only a lot bigger.

Since moving to Denver last fall, I've been bedeviled by a mild degree of static on AM that varied depending on my location in the house. It made some local and nearby stations not so listenable. So I tried direction-finding, taking a walk around the neighborhood with a headphone radio, and found that the static varied so much - it seemed idiosyncratic - that I couldn't nail it down.

Sunday morning about 10 am we heard a loud bang! The local utility came out with the trucks parked on the street just south of us. Our power was never out but I suspect they were out the next block over. That explosion sounded to me like a transformer explosion but I couldn't tell exactly what was going on. I believe the result was a transformer replacement. The distribution lines run along back lot lines around here, with no alleys, so it could have been in the middle to the block. But enough of that detail.

Since then, the static noise has been nearly eliminated, and isn't present at all on battery-powered radios. I walked around the neighborhood again this afternoon with the headphone radio and there was no static at all. A good test case was Boulder's KVCU, which is still running on aux power. It was listenable if a bit weak. The receivers at home that use AC power still get a little bit of static but it's not nearly as bad as it was.

Insulators also age and can also cause static problems. Utilities vary in their attention to infrastructure. Local distribution (generally less than 100 kv) is not covered by NERC-CIP standards, which are more for compliance and security anyway, and a bad insulator or transformer isn't going to show up on the HMI displays in a control center until it trips a relay, etc.

 

[brettbutlerisok]

All valid possibilities. I have been told by many broadcast engineers that those wall warts are very cheaply designed and made and are frequently the culprit in terms of electrical noise. So "something in the house" could indeed be any of those powering any of your devices. Even your phone charger can emit spurious noise.

The power transformer next door is pretty much the same, only a lot bigger.

Don't forget solar panels! I can't hardly use any AM radio plugged in to the wall inside my house anymore. Not too bad on battery power.

 

[davideduardo]

Don't forget solar panels! I can't hardly use any AM radio plugged in to the wall inside my house anymore. Not too bad on battery power.

Same here. We have 5 roof slopes of our "U" shaped house covered with panels and there is no way to listen to AM anywhere inside.

 

[cc333]

Don't forget solar panels! I can't hardly use any AM radio plugged in to the wall inside my house anymore. Not too bad on battery power.

A couple neighbors down the street have some! I wonder if that could be contributing? I would've thought that they'd be far enough away so as not to be much of an issue, but maybe they aren't?

c

 

[Kelly A]

Same here. We have 5 roof slopes of our "U" shaped house covered with panels and there is no way to listen to AM anywhere inside.

Are you using 'micro inverters' mounted under your solar panels or a big inverter in the house?
I hear the micro's are noisy.

 

[Mark Roberts]

Same here. We have 5 roof slopes of our "U" shaped house covered with panels and there is no way to listen to AM anywhere inside.

We had solar panels in Oakland. There was this horrific noise at 1200 kHz that rendered anything absolutely unlistenable at or near that frequency. (1200000 is a multiple of 60...hmmmm...that's an awfully high harmonic to be doing anything, I'd think - what was that inverter doing? 600 kHz wasn't a problem but that might have been masked by KEAR.) Strong local signals - San Francisco, Oakland, Peninsula area - weren't otherwise affected but there was still a deadening effect for distant signals. I had to go outside and get at least five feet away from the house in order to get those stations.

I see very few houses with solar panels in Denver. The electric rate structure does not provide much of an economic advantage for solar.

 

[davideduardo]

Are you using 'micro inverters' mounted under your solar panels or a big inverter in the house?
I hear the micro's are noisy.

Each set of panels has an inverter. That makes 5.

 

[Kelly A]

Each set of panels has an inverter. That makes 5.

Okay sure, micro-inverters. And all that wiring daisy chained from them makes a wonderful transmit antenna.

 

[brettbutlerisok]

A couple neighbors down the street have some! I wonder if that could be contributing? I would've thought that they'd be far enough away so as not to be much of an issue, but maybe they aren't?

c

Not sure, outside in my rather small back yard I have no real issues, out there it's like nothing has changed in the last 30 years. The power was out a few years ago on a sunny afternoon, I tuned in KGO (i'm in Fresno) and it was strong like nearly local, before I was even aware the power was coming back on the station faded away in to noise. Only took about a second, but it sure was eerie.

 

[Hyrum]

Aren't we getting away from the general topic.? There are a million reasons and causes of the electrical noise that has made AM radio unlistenable. No one is getting rid of their solar panels, microwave ovens, and aging insulators. The noise will remain. So AM stations won't. The lower powered stations are already hash 10 miles from the transmitter. The big guns are still there, but with half the range of 30 years ago. If they don't all switch to a digital format and all radios can't receive the signals, they will continue the progression of fading away. No legislation is or should be made to require HD radios. Even if it were so, how many would invest in one? The answer is simply to have better programming than anyone else on a band that people tune too, FM, satellite, or internet. If the message is worth hearing, the delivery system shouldn't matter. AM should not be encouraged to stay and burn a lot of electricity in 2024. There are too many boring stations offering too little quality. The big guys already know this and that's why so many group owned AM stations are rebroadcasting signals from a co-owned FM or infomercials simply to keep modulating. (please don't start a column to inform me that infomercials are a source of revenue to justify keeping AM alive) Just like the buggy whip, AM's time has come. Or is it AM's time has gone? Let's put something that might even generate water cooler talk on the air, whatever that air might be and then people might listen. Maybe advertisers might want to be a part of that and the money could be added to the budget of the FM station carrying it.