Hi Paul,
Please see these FRS Knowledge Base articles: < http://kc.flex-radio.com/KnowledgebaseArticle50280.aspx?Keywords=echo > < http://kc.flex-radio.com/KnowledgebaseArticle50288.aspx?Keywords=echo > < http://kc.flex-radio.com/KnowledgebaseArticle50160.aspx?Keywords=sdr-1000+specifications > I use ferrite on the leads to my SDR-1000 and PC. I use isolation transformers on the sound card cables. That also gets rid of the DC "hump" on the panadapter. The RFI can sometimes be caused by ground loops. I'm using a big Marantz Stereo HiFi amplifier on the sound card output, and if I ground the chassis to station ground, it hums. I use an old Shure M67 audio mixer for microphone gain, rather than software gain in the sound card. Got it cheap on eBay. The M67 does a lot better in rejecting RFI than my sound card. And I get to play with the knobs mixing different mics and watch the VU meter. Takes me back to my broadcast days. 8) RF in the shack can be a symptom of an antenna issue. I try to decouple my feedlines at the antenna and also where the feedlines enter the shack, right after my grounding plate. Ferrite is my friend. I remember running some rigs back in the 1960's where, if my lips touched the metal microphone, or my finger touched the ground on the key, I could feel RF warming. BTW, the SDR-1000 is such a good performer that you need a low-impedance connection to a power supply than can provide a solid 25 Amps. Use heavy leads to the SDR-1000. I was chasing down a problem and discovered that my power supply was not providing enough current. Mike - AA8K Paul Giusti wrote: > Hi All > > > > I seem to be experiencing on transmit what sounds like an > "echo" its sounds like a delay i.e. a few milliseconds , i'm pretty sure now > after some months of trying to eliminate it that it might be rf getting in > somehow > > > > I am using the current Test SVN as well as K6JCA consoles > and both have the same effect, so i am pretty sure i have eliminated > software issues > > > > Its a late model SDR1000 (Jan 07 Build) using a FA66 and a > Heil HM-10 Dual Insert microphone. The microphone is plugged into input 1 on > the FA66. I use sample rate of 192khz. The rear gain control is at 12 > o'clock, the front panel mix control is at 12 o'clock as is the sensitivity > on input 1. I have followed the FA66 setup guide > > > > I'm looking for any advice with maybe the wiring of the 4pin > xlr to 3 pin xlr for the heil mic..is this where my problem might be??..what > mic cable should i use?? > > > > I have spent most of the weekend earthing my station but to > no avail the problem is still apparent. > > > > Any advice would be greatly appreciated in finding the cure > of the "echo/RF " > > > > Thanks > > > > Paul - VK3APG > _______________________________________________ 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://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
