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<body class='hmmessage'><div dir='ltr'><font style="" face="Tahoma">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. <br><br>I wrapped multiple loops of the USB cable through a ferrite core and both ends. I will see how that works. <br id="FontBreak"></font><br><b><font style="font-size:16pt;" size="4">73 Doug</font><font style="font-size:16pt;" size="4"><br></font><font style="font-size:16pt;" size="4">WA3DSP</font><font style="font-size:16pt;" size="4"><br></font><font style="font-size:16pt;" size="4">http://www.crompton.com/hamradio</font></b><font style="font-size:16pt;" size="4"><br></font><br><br><div>> Date: Wed, 25 Dec 2013 11:19:55 -0500<br>> From: kb4fxc@inttek.net<br>> To: doug@crompton.com<br>> CC: app_rpt-users@ohnosec.org<br>> Subject: Re: [App_rpt-users] USB EMI?<br>> <br>> <br>> Hi Doug,<br>> <br>> I've experienced that same situation when running high power on HF. I <br>> solved it with careful application of ferrites and other RF suppression <br>> means....Note that most "snap-on" RFI suppressors don't do much on HF, <br>> especially the low HF bands--you'll probably need many turns of the USB <br>> cable thru the core(s) to do anything at all. This is a situation where <br>> some RF analysis tools come in handy. I've got an AIM-4170C, which is an <br>> incredible help to tell if/when some suppression method is heading in the <br>> right direction!<br>> <br>> Anyhow, good luck, I've been there, too! This just shows how much<br>> unexpected RF can be floating around when using various radios and amps!<br>> <br>> Merry Christmas and Happy New Year!<br>> <br>> 73, David KB4FXC<br>> <br>> <br>> <br>> On Tue, 24 Dec 2013, Doug Crompton wrote:<br>> <br>> > 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.<br>> > <br>> > Dec 23 22:07:13 WA3DSP_Allstar kernel: hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...<br>> > <br>> > 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? <br>> > 73 Doug<br>> > WA3DSP<br>> > http://www.crompton.com/hamradio<br>> > <br>> <br>> <br></div> </div></body>
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