Laptops are problematic in this regard. You can try to use the screw posts on one of the back connectors, like the video connector. Or use a lot of split or solid core ferrite beads on the Firewire cable to start with.
Jim's advice is very good too. Removing the common mode RF currents from the antenna coax shield using a choke balun before they get back to the radio hardware is the best way eliminate RFI problems. -Tim -----Original Message----- From: Russell Magnuson [mailto:r...@resultsdirect.com] Sent: Sunday, October 31, 2010 9:16 AM To: Tim Ellison; flexradio@flex-radio.biz Subject: Re: Flex-3000 freezing up on transmit Tim, I am using a notebook computer so a more formal ground technique eludes me (short of drilling holes into it in order to connect to its internal ground plan...). I'm not sure it even has a grounded metal shell type connector on it that I could connect to. So any advice you have would be appreciated. I am assuming that currently my best path to the Flex-3000 ground is through the shield in the firewire cable. - Russ, KFiK On 10/30/10 3:44 PM, "Tim Ellison" <telli...@itsco.com> wrote: > Do you have the PC grounded to the radio? > > Also you may need more ferrite beads on the Firewire cable > > http://kc.flexradio.com/KnowledgebaseArticle50370.aspx > > -Tim > > > -----Original Message----- > From: flexradio-boun...@flex-radio.biz > [mailto:flexradio-boun...@flex-radio.biz] On Behalf Of Russell > Magnuson > Sent: Saturday, October 30, 2010 3:00 PM > To: flexradio@flex-radio.biz > Subject: [Flexradio] Flex-3000 freezing up on transmit > > Hello all, > > I have been fighting a problem with my Flex-3000 setup (or one that it > is a victim of) which I believe... is related to RF getting back into > it and freezing it up (Problem: display wave form freezes on transmit > after modulation, Flex-3000 requires a power cycle/PSDR needs to be > restarted on my notebook PC). > > At first I thought it was a problem with my firewire card and all > that, but eventually got to try transmitting into a dummy load and > under this scenario the rig does not freeze up when transmitting (all > the way up to full power out/100w). > > Other details: > > * 50¹ of LMR-400 feeding a Radiowavz OCF DX 80 ( replaced RG-8X with > the > LMR-400 as part of my debug process here) > * Insertion/use of an external tuner does not seem to change the > symptoms or prevent freeze up > * Increasing output power (and Mic gain to drive it) beyond a few > watts into the antenna causes it to crash > * Problem seems to be worst on 40m, but I have had it crash on 20m as well. > Higher bands seen less prone to crashing > > Grounding: > > I have been trying different grounding things but to no avail. I DO > NOT currently have a 8¹ rod handily pounded into the ground nearby. I > have tried the incoming copper water pipe in addition to normal A/C > house ground (I also tried a 50¹ run of RG-8x to that incoming water > pipe, with the C/S shorted on the pipe end and a .01uf ceramic cap > between the center and the shield on the other end, where I then connected > the center to the GND on the Flex-3000). > > Other rigs: > > Prior to purchasing the Flex-3000 I have been running my FT-897D into > this same antenna setup with no known (or detected) issues related to > ground or RFI, etc. > > Thoughts? Ideas? Theories? What am I missing here? Is there anything > in the > Flex-3000 that maybe is futz in some way that would make it > hypersensitive to some RF(???) in the shack? Or am I missing some other angle > here? > > Thanks in advance, > Russ, KF1K > > > > _______________________________________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kc.flexradio.com/ Homepage: > http://www.flexradio.com/ > _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
