I had this problem when I first purchased my 5000A running more than about 50 watts. It turned out that RF was getting into the firewire cable.
I put ferrite chokes on each end of the firewire cable (three loops through the hole), no more problems, now I can even run the Alpha amp at full power 160m to 6m! I also put one on the microphone cable just for extra insurance. Cost about $5 each. The ferrite chokes I used are: EMI/RFI Suppressors & Ferrites 257 OHM @100MHZ SPLIT FERRITE Mouser Part #: 807-BF2930 Manufacturer Part #: BF2930 http://www.mouser.com, search on: BF2930 Unfortunately this number is now obsolete so you will have to look for the current version of the same thing. http://www.mouser.com/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppress ors-Ferrites/ You might even be able salvage the RF chokes that come attached to some computer cables at no cost. 73 Lloyd - N9LB -----Original Message----- From: Flexedge [mailto:[email protected]]On Behalf Of Robert Costa Sent: Saturday, December 22, 2012 4:15 PM To: Flex Radio List; Flexedge Subject: [FlexEdge] Suggestions All, As you may have seen from previous posts, that I have RF ingress issues on my Flex 5000a restricting my use of the flex to 40 meters and below. As I want to start addressing these issues, I would like to know what products others have used. I need to eliminate common mode currents at the feedpoint of my 80-10 meter dipole. I have seen Radio Works line isolators, but have been told that they are not very effective. I have been told to use a W2DU current UNUN from a company like the wireman. I am open to suggestions as I do not want this to be an extended engineering science fair. As this RF ingress issue has been a complete irritating experience with my Flex, I would like to hear who has used what and what the results and over all costs have been. Thank you, Robert KB6QXM _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software innovation and other technical SDR topics. _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software innovation and other technical SDR topics.
