Re: [Flexradio] High SWR indication and loss of keying
I notice that John puts the choke at the computer, Flex puts the choke at the radio and Ahti puts chokes on both ends of the USB cable. I thought that the radio would be the thing sensitive to the RF so the Flex approach makes the most sense. But I'm not sure. I have the same question concerning the audio cables going to the external sound card (Firebox etc.) I am inclined to do the belt and suspenders approach, chokes on both ends but wonder if anyone has run ferrite experiments. Incidentally, for those of you in the US who like the looks of Ahti's E cores in type N27 material, Type 77 is, apparently, similar to N27 ( http://users.catchnet.com.au/~rjandusimports/xref_mat.html ) and Amidon has a nice selection of E cores in type 77 http://www.amidoncorp.com/aai_cost_ecores.htm and Ham pricing http://www.amidoncorp.com/pricing/I haven't received mine yet so no experiments have not been run. Jon, K6JEK On Oct 16, 2006, at 11:06 AM, [EMAIL PROTECTED] wrote: I had very same problem and it appears that SWR is not the problem but RF in the shack is. I added two (2) radio shack cable type clamp on chokes to the USB cable about 6 months ago and problem resolved. Put the Chokes right at the computer where the cable plugs in. Chokes a little loose on usb cable so put a tie wrap behind them so they will remain in place on the cable. John [EMAIL PROTECTED] -- next part -- An HTML attachment was scrubbed... URL: /pipermail/flexradio_flex-radio.biz/attachments/20061016/f75aca30/ attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] High SWR indication and loss of keying
Actually, there is not much in the Flex-Radio SDR-1000 for the rf to get to. I have found that the computer system and its peripherals, mouse, keyboard etc. have been the major culprits. I had to relocate the 40M antenna away from the shack in another more distant part of the attic to keep my Athlon confuser from going into standy when running the full 100W on CW. I was using an external tuner and had rf isolators in all the feedlines along with feritte beads on the mouse and keyboard cables. RFI elimination is trial and error. 73 Jim, W4ATK ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] High SWR indication and loss of keying
I had real good luck with the T4 Radio Works Line Isolators (page 7 of their catalog http://www.radioworks.com/Catalog2006web.pdf). I am sure there are others that would work fine too. de ken n9vv Jim, W4ATK wrote: Actually, there is not much in the Flex-Radio SDR-1000 for the rf to get to. I have found that the computer system and its peripherals, mouse, keyboard etc. have been the major culprits. I had to relocate the 40M antenna away from the shack in another more distant part of the attic to keep my Athlon confuser from going into standy when running the full 100W on CW. I was using an external tuner and had rf isolators in all the feedlines along with feritte beads on the mouse and keyboard cables. RFI elimination is trial and error. 73 Jim, W4ATK ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] High SWR indication and loss of keying
On 16/10/06, Jim, W4ATK [EMAIL PROTECTED] wrote: RFI elimination is trial and error. 73 Jim, W4ATK Yes, Jim, so it is! In my case one common mode choke was not enough. I tried two cokes first at the radio end and then at the computer end. The best result was with one choke at both ends. It obviously depends on the mode of the RFI coupling due to different routing of the cables. Jon, Thank you for informing about the Amidon materials. 73, Ahti OH2RZ ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
