[App_rpt-users] USB EMI?

[Doug Crompton]

OK thanks for all the feedback. I am sorry others are having the same problem but glad I am not alone. This is the first time I have had this problem and I have a lot of wired cat 5/6 and USB floatng around the house. I wonder if the DMK is more sensitive to this. 

I wrapped multiple loops of the USB cable through a ferrite core and both ends. I will see how that works. 
73 Doug
WA3DSP
http://www.crompton.com/hamradio


> Date: Wed, 25 Dec 2013 11:19:55 -0500
> From: kb4fxc at inttek.net
> To: doug at crompton.com
> CC: app_rpt-users at ohnosec.org
> Subject: Re: [App_rpt-users] USB EMI?
> 
> 
> 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
> >  		 	   		  
> 
> 
 		 	   		  
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