AM Radio =-interference- Is there a plug-in or easy filter

[[email protected]]

I have a 1970's GE clock transistor radio. On AM stations, (1060) there is a lot of buzz/hum. However when I turn ON various CFL light fixtures around the house, the hum disappears. Is there a filter commercially available to put on the AC line? Or can I make one? I've tried reversing the plug (that used to work years ago). Any suggestions? TIA- vze2m645 at verayzon dot nat, you know what I mean.

 

[Phil Allison]

I have a 1970's GE clock transistor radio.

** Still working ??

On AM stations, (1060) there is a lot of buzz/hum.

** The usual cause is AC supply frequency modulation of AM radio signals
arriving on power wiring in the premises.

However when I turn ON various CFL light fixtures around the house, the
hum disappears.

** CFLs nearly all have a 100nF or 220nF capacitor that connects directly
across the incoming AC wires. These reduce any AM band signals to a much
lower level and so avoid the aforementioned supply frequency modulation.

Is there a filter commercially available to put on the AC line?

** Doubt it.

Or can I make one?

** A 1uF, 275VAC cap is all you need.

Wired into the back of a regular AC plug.



.... Phil

 

[michaelm]

<[email protected]>






** Still working ??






** The usual cause is AC supply frequency modulation of AM radio signals

arriving on power wiring in the premises.







** CFLs nearly all have a 100nF or 220nF capacitor that connects directly

across the incoming AC wires. These reduce any AM band signals to a much

lower level and so avoid the aforementioned supply frequency modulation.








** Doubt it.






** A 1uF, 275VAC cap is all you need.



Wired into the back of a regular AC plug.







... Phil

Thnks Phil. does that cap go in series with one lead of an ACPlug, or across thepower line.

 

[Phil Allison]

"michaelm"


** Fix you fucking settings !!!!!!!!!!!!!!

And learn how to read.



..... Phil

 

[Nightcrawler®]

"michaelm"


** Fix you fucking settings !!!!!!!!!!!!!!

And learn how to read.



.... Phil

Learn how to spell !!!!!!!!!!!!!

And, get OE Fix, too.

In all fairness to Phil, after he had his grumpy juice for
breakfast, he did state to put the capacitor across the
incoming AC line i.e. parallel. With a molded plug you would
have to be quite clever, but you may buy a replacement, two
piece plug and wire the capacitor into the circuit, minding
to heat shrink the capacitor leads.

 

[[email protected]]

Forget it, none of this shit is going to work. The simple fact is that there is so much shit putting out interference in that band that nothing is going to eliminate it.

You can't shield it from the power line because it is conming in from THE ANTENNA ! You would have to filter the frequencies you want to recieve.

It's different when you are out in a truck on the highway in bumfuct Kansassomewhere. Then AM can work.

Think about it, AM is about one megacycle. Yup, not even Hertz. It's that old. I hate to say it, but AM is just about dead. I used to like CKLW. In fact CKLW used to be one of the most popular stations in the whole country. The problem now is that even your fucking clothes apparently enamate RF in that low band.

Shortwave is just as bad.

There is a damn good reason that the technology has tended toward higher frequencies. In fact, like OVER ten years ago I advocated the elimnination ofthe VHF band for television. On channel 3 (US, about 60 Mhz) if a car was driving down the road and had a bad spark plug wire it would cause interference.

**** that.

 

[Nightcrawler®]

Forget it, none of this shit is going to work. The simple fact is that there is so much shit putting out interference in that band
that nothing is going to eliminate it.

You can't shield it from the power line because it is conming in from THE ANTENNA ! You would have to filter the frequencies you
want to recieve.

It's different when you are out in a truck on the highway in bumfuct Kansas somewhere. Then AM can work.

Think about it, AM is about one megacycle. Yup, not even Hertz. It's that old. I hate to say it, but AM is just about dead. I used
to like CKLW. In fact CKLW used to be one of the most popular stations in the whole country. The problem now is that even your
fucking clothes apparently enamate RF in that low band.

Shortwave is just as bad.

There is a damn good reason that the technology has tended toward higher frequencies. In fact, like OVER ten years ago I advocated
the elimnination of the VHF band for television. On channel 3 (US, about 60 Mhz) if a car was driving down the road and had a bad
spark plug wire it would cause interference.

**** that.

You seem to be retarded. The OP already stated that the noise was eliminated by
turning on a CFL.

If the OP could kill the power to the receptacle, solder some extension wire to the
cap leads, and then wire the cap across the back of the receptacle. Minding to heat
shrink the leads of the cap, and using a larger heat shrink, encapsulate the cap and
all of the smaller heat shrink. Make the extension leads 6" long.

 

[mike]

You seem to be retarded. The OP already stated that the noise was
eliminated by
turning on a CFL.

If the OP could kill the power to the receptacle, solder some extension
wire to the
cap leads, and then wire the cap across the back of the receptacle.
Minding to heat
shrink the leads of the cap, and using a larger heat shrink, encapsulate
the cap and
all of the smaller heat shrink. Make the extension leads 6" long.

Wouldn't it be easier to put the cap inside the radio?

Be careful with your choice of cap.
I put a quality 600V cap across 220VAC inside the dryer to
bridge the phases to make X10 work. Worked great for two
years before it exploded spectacularly. Good thing it was
inside a metal box.

 

[Phil Allison]

"Nightcrawler®"

"Phil Allison" <

Learn how to spell

** Get a life - you fucking IDIOT !!!!!!

 

[Phil Allison]

<[email protected]

Forget it, none of this shit is going to work.


** So you do not understand the issue.

AM radio often signals "piggy back" into premises on the AC power and are
then re- radiated with supply frequency related modulation - mainly 100
or 120Hz and harmonics.

They also arrive by penetrating walls and windows without such modulation.

The loopstick antenna in the OP's radio picks up either or both.

It may even have a small cap connecting to the incoming AC to enhance the
effect.

Get it now?


..... Phil

 

[Phil Allison]

"mike"

Wouldn't it be easier to put the cap inside the radio?

** Worth a try - if it will fit.

Be careful with your choice of cap.
I put a quality 600V cap across 220VAC inside the dryer to
bridge the phases to make X10 work. Worked great for two
years before it exploded spectacularly.

** My post specified a 275VAC cap ( aka class X1 or X2 suppression caps) .

These are specially would to avoid internal corona that destroys ordinary
film caps wired across the AC line.

If you cannot get any, try two 600V film caps in series - that ought to
work OK too.



..... Phil

 

[[email protected]]

What the ****.

"You seem to be retarded. "

Yeah well my shit that I design and build works.

What say you ?

 

[[email protected]]

Zanother thing. You think you can prevent a reciever from recieving that which to it is tuned ? All that fucking noise is right there in the passband.

who the **** here is so damn good that they cn selectively reject the noise wehn it is in the same bandw, and frequency, as the desired signsl ?

I don't know what kind of schoopkls they got down under, b ut in between buxting your heads and shit, they must be pretty fucking good.

Look up Lewin A.R.W. Edwards if you want to see a REAL resume'. In fact he toned his resume' down a bit. Maybe it wss embarrassing too many people.

Know what I say when this shit happens ?


Fukum.

 

[[email protected]]

God damn am I toast right now.

 

[William Sommerwerck]

wrote in message

Another thing. You think you can prevent a reciever from receiving
that to which it is tuned? All that fucking noise is right there in the
passband.

Who the **** here is so damn good that they can selectively reject
the noise wehn it is in the same bandw, and frequency, as the desired
signal?

If RFI is coming down the power line, it can be choked before it reaches the
receiver.

I've done this with FM tuners. It reduces multipath that gets in through the
power line and the antenna cable's shield.

 

[Allodoxaphobia]

They also arrive by penetrating walls and windows without such modulation.

Not if the window glass is "Low-E" and the walls are stucco.
Such dwellings are almost a Faraday cage.
I live in one. Most of my AM reception is of RF trash
generated _inside_ the house.

 

[Geoffrey S. Mendelson]

Not if the window glass is "Low-E" and the walls are stucco.
Such dwellings are almost a Faraday cage.
I live in one. Most of my AM reception is of RF trash
generated _inside_ the house.

I found this idea on a web page from a company that makes small high gain
antennas for shortwave listening.

Take a portable radio and find the end of the "noise cloud" around your
home an put an antenna there. Of course if you are in a tight urban
area, or an apartment, you may never find it. :-(

Geoff.

 

[Michael Black]

I found this idea on a web page from a company that makes small high gain
antennas for shortwave listening.

Take a portable radio and find the end of the "noise cloud" around your
home an put an antenna there. Of course if you are in a tight urban
area, or an apartment, you may never find it. :-(

I remember forty years ago I could just stick a few feet of wire on the
SP-600 and reception was fine. Now, there is so much noise from all the
electronic junk that didn't exist back then, that you really need the
antenna outside, or at the very least, next to the window. The signals
suddenly leap out, but it's a combination of stronger signals from
outside, and weaker signals from inside.

Michael

 

[amdx]

I have a 1970's GE clock transistor radio. On AM stations, (1060) there is a lot of buzz/hum.

However when I turn ON various CFL light fixtures around the house, the
hum disappears.

Leave the light on!
Put a shade on it?
Paint it black?

 

[[email protected]]

"Now, there is so much noise from all the
electronic junk that didn't exist back then..."

That's what I'm talking about. These days if it ain't Ghz there is all kindof noise all over the place. Sure there is some on the power lines etc., but it is also in the air.

Just for a test, if anyone is so inclined, just take a scope probe and connect it to a big piece of metal. You are going to see more shit there than.... well, I lack a proper metaphor at this moment. Sorry. But there is alot. Sometimes I'm surprised anything works.