[Elecraft] K3 birdies - question?

[KC2UEE]

Aha!  I think you're on to something here Bill.

My RG-8 actually snakes its away around one of my entertainment centers
where I happen to have a cable modem, network switch, and seperate wireless
router all in the same spot.  I have a PS3, Xbox360, and an Onkyo TX-NR905
receiver all wired by CAT-5 into the switch, plus the wireless router also
wired into the switch is only a few inches away.  The RG-8 runs behind all
of that stuff, and if I recall, I simply have the cat5 cable laying loosely
around it.  There also happens to be several wall-wart transformers behind
the entertainment center, which I'm sure aren't helping the situation.

When I get home, I'll try and turn off the network devices and see what
happens.

Like you, I'm also a computer geek hihi.  I've got 2 home built PC's, a
Mac tower, and 3 laptops floating around the house all networked wirelessly.

It never crossed my mind to check the network for EMI... thanks again for
the suggestion!

73,
James KC2UEE

On Wed, Mar 4, 2009 at 1:07 PM, William Evans <w4ish.bill at w4ish.net> wrote:

> James,
> I believe what you are hearing are harmonics from ethernet cables.  I
> listened on 28.380, and sure enough, I heard one of the tones there also
> which go away when I complete shield the antenna (dummy load) or remove it
> completely.  I have been meaning to do something about these numerous
> network induced tones for a long time, but I haven't gotten around to it
> since they affect the higher frequencies the most (i.e., the "quieter
> bands").  Toroids and lots of shielding on all ethernet cables are required,
> and I have my whole house wired (about 6 computers, plus various routers,
> wi-fi, etc.  Often the switching power supplies for these units generate a
> lot of noise.)
>
> Bill
> W4ISH
>
>