Hello,

Not too sharp with noise reduction techniques.

And, too much of a Sr. Citizen now to actually build chokes, etc. myself
anymore, but would like to ask the following, please.

Have a new WinRadio Excalibur receiver, and it appears that I am picking
up a lot of noise from nearby "stuff":
Possibilities, I think, would include:

Comcast Router
PC Modem
And, a whole bunch of wal-warts which I assume are switching types.

Are there inexpensive, simple, ferrite toroids that I can clip on wires
that may help ?
Any that R/S sells that are worth a try ?

For the wal-warts, should they go on the AC input, the dc output, or both ?

Should they also go on USB cables between the PC and receiver module ?
All USB cables ?

How about the Modem to Router lead, and the Router to PC lead ?

Any part of the coax lead in from the receiving (only) antenna ?
(doubt it, but thought I'd ask this one anyway)

Any thoughts would be most appreciated.

Thanks,
Bob

On Fri, 19 Nov 2010 13:46:32 -0500, Bob wrote:

Any thoughts would be most appreciated.

Hi Bob,

I clipped all of your questions because they can all be answered in a
word:

Y E S

Now we can move on to "thoughts."

There are two modes for noise entry: radiation and conduction.

Radiation comes from the source "over the air."

Conduction comes from the source "through wire."

The Y E S answer snubs both at the source by putting a lot of Z in
line with the generator thus reducing its drive for either mode.
However, this is sometimes not enough and that is generally where the
focus on conduction can pay off.

Now, when I said noise can come in "through wire," think of all the
wire that interconnects your listening station, and:
Does that wire have a path to a noise source?

Break that path.

Unfortunately, the path can be obscure. One such blind spot that
trips many up is the power lead, and the 19th century network called
house wiring. One thing about this noise network is that it often
follows a hub and spoke style of design. If your receiving station
shares a breaker with the noise generator, that noise current is being
siphoned into your receiver. What drives most folks nuts about trying
to solve that is when they add a "ground" to their rig, the noise gets
worse! To some degree this is called a ground loop.

Try moving your power plug to another socket in another room (which,
presumably, is on a different breaker). A method for diagnosing where
your problem is coming from is to use a portable radio as a noise
detector (much as you would use a metal detector at the beach).
Another method is the throw breakers one at a time and note if some
noise abruptly vanishes. You will have then isolated your problem to
a noise network branch.

This should keep you from winding chokes for a day or two.

73's
Richard Clark, KB7QHC

On Nov 19, 10:46*am, Bob wrote:
Hello,

Not too sharp with noise reduction techniques.

And, too much of a Sr. Citizen now to actually build chokes, etc. myself
anymore, but would like to ask the following, please.

Have a new WinRadio Excalibur receiver, and it appears that I am picking
up a lot of noise from nearby "stuff":
Possibilities, I think, would include:

Comcast Router
PC Modem
And, a whole bunch of wal-warts which I assume are switching types.

Are there inexpensive, simple, ferrite toroids that I can clip on wires
that may help ?
Any that R/S sells that are worth a try ?

For the wal-warts, should they go on the AC input, the dc output, or both ?

Should they also go on USB cables between the PC and receiver module ?
All USB cables ?

How about the Modem to Router lead, and the Router to PC lead ?

Any part of the coax lead in from the receiving (only) antenna ?
(doubt it, but thought I'd ask this one anyway)

Any thoughts would be most appreciated.

Thanks,
Bob

Hi, Bob.
I had to Goggle the receiver to see what it was all about. So, now
some questions about the noise.

You have already determined the noise is continuous and repetitive by
thinking it may be from adjacent computer equipment. Does the noise go
away when you set the radio to FM? If it does, then the noise is
coming in from the antenna. If not, the noise is being picked up by
the radio chassis. Did you bond it metal radio box to the computer
metal chassis or housing? I hope you are not using a plastic cased lap
top computer.

I see the radio uses a USB connection to the computer. Do you have any
other USB devices connected to the computer? If so, disconnect them
all with the computer off, then turn the computer on and the radio on.
Still same noise. If no, plug in other USB devices one at a time and
listen for noise. If one of them is the source, you may need to get a
separate powered USB expander and plug all the offending devices into
it.

IF not USB related, you will need to go trough the steps of
determining which accessory is causing the noise.

Are you using a standard CRT for a monitor, or a LCD monitor? The LCD
will generate noise from the scanning electronics in the display panel
and unless the back light is LEDs, the AC operated electroluminicent
panels are quite noisy. Physically move the radio as far as you can
from the monitor.

You asked for thoughts and I have one other. Except for the noise, how
do you like the radio?

Paul, KD7HB

On 11/19/2010 1:34 PM, Richard Clark wrote:
On Fri, 19 Nov 2010 13:46:32 -0500, wrote:

Any thoughts would be most appreciated.

Hi Bob,

I clipped all of your questions because they can all be answered in a
word:

Y E S

Now we can move on to "thoughts."

There are two modes for noise entry: radiation and conduction.

Radiation comes from the source "over the air."

Conduction comes from the source "through wire."

The Y E S answer snubs both at the source by putting a lot of Z in
line with the generator thus reducing its drive for either mode.
However, this is sometimes not enough and that is generally where the
focus on conduction can pay off.

Now, when I said noise can come in "through wire," think of all the
wire that interconnects your listening station, and:
Does that wire have a path to a noise source?

Break that path.

Unfortunately, the path can be obscure. One such blind spot that
trips many up is the power lead, and the 19th century network called
house wiring. One thing about this noise network is that it often
follows a hub and spoke style of design. If your receiving station
shares a breaker with the noise generator, that noise current is being
siphoned into your receiver. What drives most folks nuts about trying
to solve that is when they add a "ground" to their rig, the noise gets
worse! To some degree this is called a ground loop.

Try moving your power plug to another socket in another room (which,
presumably, is on a different breaker). A method for diagnosing where
your problem is coming from is to use a portable radio as a noise
detector (much as you would use a metal detector at the beach).
Another method is the throw breakers one at a time and note if some
noise abruptly vanishes. You will have then isolated your problem to
a noise network branch.

This should keep you from winding chokes for a day or two.

73's
Richard Clark, KB7QHC

Nice and succinct Richard. Thanks from me even though I don't have such
a problem right now, because even though I know everything you said,
it's good to have it stated clearly by someone else.

I will be saving this in my archives.

tom
K0TAR