In reference to my earlier posting regarding a severe noise problem on
frequency 11955 kHz - The high noise level is still there with and without
the outdoor antenna connected. I've returned my Kenwood R-5000 receiver to
the local Kenwood service facilities (Cerritos, CA) and am temporary using a
Grundig eTraveller World Receiver until my R-5000 is repaired and returned.
However, even with the Grundig have found that I have the same noise problem
on 11955kHz. I'm using three different antennae - one amplified vertical
and two long wire. Could the noise problem being thru the mains (117 vac
house wiring)? This doesn't seem logical as I am running the Grundig off of
batteries with no connection to the mains. Could the problem be related to
nearby Pt. Mugu Naval Air Station who does experimental work for the Navy?
Would all fellow SWLs who live in the central and southern California check
and see if they have any noise problem on 11955kHz? Thank you.

Firstly, recall that you are amplifying the signal before it reaches your receiver. It will amplify whatever is received. Frequently the increase noise and produce mirrors of multiples of frequencies too.

As far as the noise is concerned, is it continuous, or intermittent ? Does it seem to be man-made or is does it seem naturally generated ?

Atmospheric noise can be intense ahead of advancing storm systems, and can be a guide to when to pull the plug out of the wall S. Noise can be generated by bad power lines or dimmer switches.

Some sounds can be classified as noise in that they are generated by digital equipment at radio frequencies and is unwanted if you are a shortwave listener.

If you clip a playing card onto your tire rim, it generates a noise as it makes contact with the spokes. The faster you pedalled, the more magnificent the sound, which is why little boys put them on their bike. In a similar way, digital equipment will produce a signal as the transistors are turned on and off in the regular functioning of the machine. The faster the switching, the higher the frequency of the signal, and by the time it is switching at radio frequencies, the signal will leave the equipment as if it were a transmitting antenna. If the signal gets into the power lines, it is very difficult to remove or prevent your receiver from seeing.

Can you describe the noise ? The Navy may or may not be the culprit. If it is weather related, you can install a device to bleed atmospheric electricity off the antenna line to ground. You definitely want a good earth ground. Even a coat hanger stuck into the ground is better than nothing in reducing noise. The other thing is matching your antenna to your equipment with a matching device of some kind. Sloper antennas and loops are better at limiting noise. Some receivers have noise limiters or noise blankers which may be hlepful sometimes. There are also devices the connect between the antenna and the receiver which will use phasing to cancel some noise.

I hope this helps. Best wishes.

God gives Peace not war +

In article ,
"JimmyT" wrote:

In reference to my earlier posting regarding a severe noise problem
on frequency 11955 kHz - The high noise level is still there with and
without the outdoor antenna connected. I've returned my Kenwood
R-5000 receiver to the local Kenwood service facilities (Cerritos,
CA) and am temporary using a Grundig eTraveller World Receiver until
my R-5000 is repaired and returned. However, even with the Grundig
have found that I have the same noise problem on 11955kHz. I'm using
three different antennae - one amplified vertical and two long wire.
Could the noise problem being thru the mains (117 vac house wiring)?
This doesn't seem logical as I am running the Grundig off of
batteries with no connection to the mains. Could the problem be
related to nearby Pt. Mugu Naval Air Station who does experimental
work for the Navy? Would all fellow SWLs who live in the central and
southern California check and see if they have any noise problem on
11955kHz? Thank you.

I'm in Ventura not far from you and I don't have any noise on 11,955
kHz.

To test your receiver disconnect the antenna and see if the noise goes
away. If it does then it is coming from your lead-in or antenna.

If the noise does not go away with the antenna disconnected the radio
has a problem or it could be coming from the AC power. If possible
operate the radio on batteries.

Use the portable to try to locate the noise source.

Try turning off the house breakers to see whether the noise is coming
from some appliance in your house.

--
Telamon
Ventura, California

The noise seems to becoming from my computer and printer across the room. I
notice no other loud steady noise level on any other frequencies. Is the
frequency of 11955kHz some harmonic of an RF signal being produced by the
computer and/or printer. The adjacent frequencies are free of this noise.
I've only started monitoring this frequency four months ago. I assume that
the noise could have always been there. I'll listen again when all of the
computers, printers, TVs, etc. are turned off for the night and will report
back tomorrow.

"JimmyT" wrote in message
...
The noise seems to becoming from my computer and printer across the room.
I
notice no other loud steady noise level on any other frequencies. Is the
frequency of 11955kHz some harmonic of an RF signal being produced by the
computer and/or printer. The adjacent frequencies are free of this noise.
I've only started monitoring this frequency four months ago. I assume
that
the noise could have always been there. I'll listen again when all of the
computers, printers, TVs, etc. are turned off for the night and will
report
back tomorrow.



Computers are notorious noise makers. The first thing you want to do is
turn everything off in the house and then turn each thing on at a time and
listen. Some things are thermal in nature and don't show themselves until
they run a wile. It took me a wile to find a quiet monitor for the shack. I
got a cable modem that makes a hell of a lot of noise even when its not on,
I have to unplug the ******* from the main to shut it up.


--
73 and good DXing.
Brian
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A lot of radios and 100' of rusty wire!
Zumbrota, Southern MN
Brian's Radio Universe
http://webpages.charter.net/brianhill/

EMAIL-
(Hide the $100 to reply!)

I've discovered the source of the RFI that I thought initially was an
internal R-5000 problem. It turned out to be my home computer network
LinkSys BEFSR41 router is causing the RFI with my shortwave radios on at
least one or more frequencies. The first frequency that I observed was
11955 kHz. The router and my computer, printer, scanner, and cable modem
are in the same room with the shortwave receiver. The distance between the
router and receiver is approximately ten feet across the room. I've
isolated the RFI source to the router by leaving a battery-powered receiver
on tuned to 11955 kHz and powering up and down individually the computer,
printer, scanner, cable modem, and router. Thank you all for your
suggestions.