Nasty carriers in the AM windows...

[wb4iuy]

I've noticed, over the last few weeks, a non-stop carrier drifting between 3880-3885 & 7285-7295. They're kinda ragged around the edges, seeminly modulated by a nasty AC hum/buzz. Do any of you have similar birdies/trash in your area?? I'm wondering what this might be...

Dave WB4IUY
www.WB4IUY.net

[KF1Z]

I've noticed, over the last few weeks, a non-stop carrier drifting between 3880-3885 & 7285-7295. They're kinda ragged around the edges, seeminly modulated by a nasty AC hum/buzz. Do any of you have similar birdies/trash in your area?? I'm wondering what this might be...

Dave WB4IUY
www.WB4IUY.net

Sounds like a computer monitor.

Is there one nearby?

[wb4iuy]

Sounds like a computer monitor.
Is there one nearby?

There are several here, but I've powered them all down and have no change. I'm pretty sure it's local, as it is on 80m all day long. I'm still poking around to see what it might be, just wondered if anyone else had run into something similar in the past.

Dave

[KF1Z]

By powered down... do you mean unplugged?

Same as anything interference wise...
Absolutely disable, unplug, turn off breakers, take out batteries...
Then go from there.

[wb4iuy]

By powered down... do you mean unplugged?

Same as anything interference wise...
Absolutely disable, unplug, turn off breakers, take out batteries...
Then go from there.

I didn't pull the plug from the receptacles when I checked them. I'll go back and give it a whirl. I did disconnect the washer/dryer, they're the new computer controlled versions and spew out lots of garbage when they run.

Dave WB4IUY
www.WB4IUY.net

[Blaine N1GTU]

i had a small little VCR once that spewed trash all over the spectrum, all it needed was to be plugged into an outlet, did not need to be turned on.

[k4kyv]

I did disconnect the washer/dryer, they're the new computer controlled versions and spew out lots of garbage when they run.

i had a small little VCR once that spewed trash all over the spectrum, all it needed was to be plugged into an outlet, did not need to be turned on.

Is there any consumer electronic junk or home appliance made these days that doesn't spew trash all over the spectrum?

[WA3VJB]

Your description sounds a little different than what I am about to suggest, but our plasma TV generates a tremendous # of birdies on 80m and it's worth checking that as a source too.

It's more than just in the AM windows, however, and throughout the band.

[WB4AIO]

I've noticed, over the last few weeks, a non-stop carrier drifting between 3880-3885 & 7285-7295. They're kinda ragged around the edges, seeminly modulated by a nasty AC hum/buzz. Do any of you have similar birdies/trash in your area?? I'm wondering what this might be...

Dave WB4IUY
www.WB4IUY.net

It might be a touch lamp.

They need to be unplugged. And then this protocol needs to be followed:

http://3950.net/wp-content/uploads/2010/02/AM-864-destruction.jpg


Good luck finding the source!

Kevin, WB4AIO.

[wb4iuy]

Well, I'm now going to have to hunt around in the neighborhood... I powered the entire house down at the main disconnect outside. Ran the IC-756 on battery power, still have it. S-9 on both 75 & 40m... I need to rig up some sort of portable setup with my old TS-120 to walk around.

Dave

[Knightt150]

I think the problem is the new plasma TV's I have been told they are notorious for this. I have a birdie on 7260 Kc every now and then, and I think it is a TV.
When someone comes up with a fix let me know.

John W9BFO

[KF1Z]

I think the problem is the new plasma TV's I have been told they are notorious for this. I have a birdie on 7260 Kc every now and then, and I think it is a TV.
When someone comes up with a fix let me know.

John W9BFO

Have a plasma tv shoot in the neighborhood

[KF1Z]

I noticed the most wonderful Perseus SDR receiver has gone and got it's "FCC part 15 compliance".

Which means it can't generate crud to interfere....

But, the worst part...it has to ACCEPT interference !  isn't that just great...


I wonder how this would play out if a complaint was filed with the FCC of some neighbor's TV, or CB or even the power company's noisy insulators, if they found out the reciever was Part 15 compliant?

Would you really just have to live with the interference?

[ka3zlr]

Hello,

 I Been following along here, is this noise on a Transceiver or stand alone receiver, does it change with differing equipments, is it louder on Vertical or Horizontal or it doesn't matter, when you pull the feedline off the rig is it still noticeable or not, Type of antennas are you using, is there any heavy Industry in the area, are you close to farmland, can you Isolate your power line.

Things to think about.

73

Jack.

 

[K5UJ]

<<Is there any consumer electronic junk or home appliance made these days that doesn't spew trash all over the spectrum?>>

Not many that's for sure.  The allure of the switcher is just too much to ignore:  They are lightweight and cheap to make.  A big bonus is they can be made to handle any line service so one design is international.  My supply for my mac says on the case that it will handle 100 to 250 v.  Of course a single linear supply won't do that. 

[k4kyv]

But it would cost the manufacturer only a few pennies to clean up the RFI.

[W1RKW]

<<I've noticed, over the last few weeks, a non-stop carrier drifting between 3880-3885 & 7285-7295. They're kinda ragged around the edges, seeminly modulated by a nasty AC hum/buzz. Do any of you have similar birdies/trash in your area?? I'm wondering what this might be...

Dave WB4IUY
www.WB4IUY.net
>>

Dave,
I heard something similar to what you describe yesterday.  It appeared to drift too and go up and down (QSB) with other signals.

I had a pretty nasty QRN here a few months ago and traced it to a neighbors house.  Per recommendation of K1JJ, drive around with your AM radio tuned  as high as it will go ie, 1710KHz and you should be able to determine if local or not. I located a strong source on my street this way but what I heard yesterday was not local.

[K5UJ]

<<<But it would cost the manufacturer only a few pennies to clean up the RFI.>>>

We now enter the strange world of modern day consumer product manufacturing run by people with MBAs.

True, the per-unit cost is small.   But let's look at a made up example to illustrate why it isn't happening.  Sam's Global Wall Wart company makes wall warts for sale in bulk to (name any consumer electronics company) complete with re-branding if they want it.  Someone, Nokia let's say, has a cell phone they need a battery charger for.  All this business is motivated by more profits to keep shareholders happy and one way you do that is by holding down costs on parts.  Sam's and all the other wall wart mfr's need orders to stay in business.  So, they compete with each other on price and one way to do that and maximize profit is to keep components to a minimum.  Nokia, wants to sell their product all over the world so the charger has to work just about anywhere with minimal alteration.  A relative handful of SWLs and hams are of little concern to them--the MBAs in suits may even be oblivious to the existence of such people. 

Now, Sam's and the rest save a few cents gutting out the bleeder caps, little ferrite beads or what have you that does the filtering but a few cents multiplied by millions and millions of these things sold all over the world adds up to serious money. 
Then there is the time and labor saved in not having to source the parts, inventory them, track supplies, pay for more labor to add them on the assembly line...because there is so much focus on the bottom line as a result of international commerce and competition among other things, these products are stripped down to the bare minimum needed to get them working, and RFI filtering gets cut. 

Indirectly consumers are to blame.  Most people shop and make buying decisions mainly on price.  Let's face it, if you are selling a telephone answering machine made in the U.S. and it is all quality with RFI filtering and everything and costs $50 and you are also selling an answering machine made off-shore with none of that and it costs $30 which one will people buy?

Unfortunately most people are just not educated on why quality is important and how to look for it and why it is worth paying for it.  Even hams.  I'm amazed at how many hams buy cheap MFJ feedline tuners.

Meanwhile there is a tidal wave of these things coming in all the time because they are now used with so many products and apparently the FCC doesn't want to deal with it.  There is too much money involved and, if you are not a ham, you probably do not see any problem in need of a solution.   Yes, a law is being broken, but people drive faster than the speed limits all the time.  Some laws get less attention than others.

[k4kyv]

Yes, a law is being broken, but people drive faster than the speed limits all the time.  Some laws get less attention than others.  

I get a chuckle out of those who self-righteously proclaim that all ham rules should be followed to the letter of the law, and that anyone who goes 10 minutes 15 seconds between IDs or runs 50 watts beyond the legal limit is not worthy of keeping his licence, yet have no problem with driving at 85-90 MPH down the interstate.

Which violation poses greater potential for harm to the public?

[flintstone mop]

Power line arcing can do that traveling thing in your radio too.

Fred

[steve_qix]

I recently built a new computer for myself, and was amazed - when the comptuter was not turned on, but only plugged in how much noise was generated.  I took the power supply apart, and made a filter from a single type 43 core wrapped with about 7 turns (twisted pair) [between the line and the power supply], and a .05uF capacitor from each side of the line to ground [right where the line enters the power supply].  This elminiated the problem completely.  There was plenty of room inside of the power supply to fit the filter.

Before the modification, when the computer was actually on, the interference was so bad, local broadcast stations were wiped out.

Class B compliant before modification?  Highly suspect 

[K5UJ]

it is a tragedy that a few simple parts that could solve all our buzzie woes are left off to save money. 

If the FCC had teams of RFI inspectors at all the ports, it would take only one or two incidents where they turn back an entire tanker ship of wall warts and these manufacturers would get the message and start doing factory mods to their products. 

Unfortunately there are already millions of them in here in use now.

[ke7trp]

Astron power supplies that are switchers put out this signal in the AM window of 80 and 40 meters.  I know, because I purchased a 35 amp unit and had this problem.  Good luck in your search!



C

[k4kyv]

it is a tragedy that a few simple parts that could solve all our buzzie woes are left off to save money.  

Not that the problem was unanticipated long in advance.  ARRL and the ham rags like CQ, 73 and Ham Radio gave the ham public numerous warnings as far back as the early 60's about likely interference problems from the coming digital era, and the imminent vulnerability of the new solid state consumer gadgets to RFI from amateur transmitters. No-one in the amateur community paid much attention and little was said until the problem had become a reality, but by then it was too late.

Similar warnings about the upcoming change in the AM power limit were posted in The AM Press/Exchange in the early 80's, based on public statements by the FCC's Private Radio Bureau officials, and numerous p.e.p. clauses had already appeared in several rulemaking dockets from the 70's and early 80's that failed to pass for other reasons, but when the power limit proposal first came out, most of the AM community appeared to be taken by total surprise. Actually, the concept was old hat by then. The whole thing probably could have been headed off at the pass if the ham community had taken an interest when the first warning signs appeared. There was little or no mention of this in the mainstream ham rags, so how were typical hams even to know?

That's one of the problems with mainstream society in this country, and explains why we have so many apparently unsolvable social and economic problems to-day.  We are a crisis-driven society.  Things have to get totally out of hand and reach a crisis stage before the media and the public are willing to even talk about the problem, let alone take any action, and often it is too late by then.  In the meantime, media consumers are preoccupied with rubbish like Lebron, Tiger Woods, Britney and Paris. The energy debate we are having now is practically an exact re-run of what took place in 1974 and the few years that followed.

[John Holotko]

I had a situation like that with strange carriers up and down the band. It turned out to be caused by a noisy network hub.