I just got back from Radio Shack and hooked up the transformer. Made a big difference. But I also noticed another strong spur down 22khz. The 11khz one is almost gone now but the 22khz one may be a problem. Any reports of a 22khz spur also? The transformer seems to have no effect on the 22khz spur. Frank WY3D
----- Original Message ----- From: A.R.S. - W5AMI To: Jerry Flanders Cc: Frank Mayer ; FlexRadio@flex-radio.biz Sent: Monday, January 22, 2007 12:32 PM Subject: Re: [Flexradio] spam: Spur on AM On 1/22/07, Jerry Flanders <[EMAIL PROTECTED]> wrote: > If it is actually a ground loop, I think my first approach would be > to try to find that loop and eliminate it, rather than spending $40 > and a trip to a RS store. > > Jerry W4UK > Jerry, This has been an issue for some time with Flexer's using AM. I have no problems with ground loops in any mode, and using a Henry 3K Classic export. If it is a ground loop, it is within the black box and nothing you can do on the outside. Flex duplicated the problem in their lab and the only solution they could find was to add the 1:1 isolation xfmr (this is what I was told). Even at that, the spur was not eliminated, but reduced 50 db down from the actual carrier transmitted on the fundamental freq. In some cases, that's not enough if you're +60 db on a local ham. I can run SSB at the legal limit without the 1:1 and have no spur down the band, but inject a carrier with the same PEP, and there it goes. Carrier AND audio is heard 11kcs down. So where is my ground loop? IMHO, OUTS 3 & 4 should have been better isolated within the SDR or the Delta-44. I got a nasty phone call about it before I knew, and another ham I know nearly got a fine for malicious interference... Brian / w5ami -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.17.4/644 - Release Date: 1/22/2007 7:30 AM -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070122/c6fa7184/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 Knowledge Base: http://kb.flex-radio.com/
