My guess, and only a guess is that HV transmission line a mile and a
half away. Is it a 230 KV line, real tall tower structures? If you
have a portable SW rx you could take a nice healthy walk in its
direction and see if the noise gets worse. I don't think its caused
by the sun, because I don't have that particular noise here and the
sun affects us all at about the same time. The reason it sounds like
a HV transmission line is because as the morning progresses and
electrical demand increases the line is generating more noise, it's
like a corona noise you hear on a mobile antenna sometimes, a frying
or hiss. It's probably worse in dry weather and you have a lot of
that in Nevada. You might try a JPS noise canx device, or the MFJ
version, MFJ-1025 or 1026, but you will need a noise sense antenna for
the device to pick up the noise in order to canx it out before the
radio.
gud luke Joe
73
Dale, k9vuj
On 08, Mar 2010, at 0:17, Joe wrote:
> I posted this problem last month..I didn't really get much help so I
> will
> pose the question/problem again, in the hopes someone can suggest an
> avenue
> of discovery. I am getting more and more frustrated.
>
> Joe Wolfe
> WA6RKN
> Reno, Nevada
> ****************************************
>
> About a month ago, my noise floor on 40 and 75m , ie:...white
> noise....rose
> to
> 9 and 10 over. In the early AM, the noise floor is where it normally
> is...1 - 3 s
> units. Then, around 9 or 10, give or take, the noise floor
> gradually climbs
> back up over 9. Temperature does not appear to be the culprit.
> Feed line
> (RG-8X) tests good and no water present. Balun was replaced..no
> change in
> noise characteristic. (Antenna is a BuxComm 6-80 Windom at 30 feet.)
>
> I connected the radio (Kenwood T-2000X) to a battery, and turned off
> the
> master switch so no power was coming into my house.. No change in
> noise
> level. There are no overhead wires in my neighborhood and the
> closest major
> overhead power line is a mile and a half away.
>
> The frustrating thing is that it is pure white noise..no electrical
> type of
> noise...buzzing, chirping, whistling, crackling, etc., just what you
> hear
> for a noise floor.
>
> Any thoughts? What instrument would be needed to have something
> like this
> down? The AM radio trick sure doesn't work...no overhead
> transformers to
> knock about. Mercury vapor street lights are off when the noise level
> starts to climb in the late morning.
>
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