[App_rpt-users] USB EMI?

[David McGough]

Hi Doug,

I've experienced that same situation when running high power on HF. I 
solved it with careful application of ferrites and other RF suppression 
means....Note that most "snap-on" RFI suppressors don't do much on HF, 
especially the low HF bands--you'll probably need many turns of the USB 
cable thru the core(s) to do anything at all. This is a situation where 
some RF analysis tools come in handy. I've got an AIM-4170C, which is an 
incredible help to tell if/when some suppression method is heading in the 
right direction!

Anyhow, good luck, I've been there, too! This just shows how much
unexpected RF can be floating around when using various radios and amps!

Merry Christmas and Happy New Year!

73, David KB4FXC



On Tue, 24 Dec 2013, Doug Crompton wrote:

> I had to restart asterisk after I got this message and my DMK went batty keying the transmitter at some crazy rate sounding like CW.
> 
> Dec 23 22:07:13 WA3DSP_Allstar kernel: hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
> 
> Curious about the EMI? because I was operating 75 meters phone 600 watts at the time this happened. The server and USB to DMK cable are in the basement well away from the antenna so I don't know if it is a coincidence or not. Anyone else ever seen this? Does the EMI in the message mean  electromagnetic interference? 
> 73 Doug
> WA3DSP
> http://www.crompton.com/hamradio
>