Correction: “bonded and grounded” not “bounded and grounded.” Sorry for typo…. ;-)
73, Dave - N5DCH > On Nov 24, 2021, at 11:49 AM, David Herring <[email protected]> wrote: > > I don’t disagree with K4TAX. It’s up to the operator to work out RFI at > one’s station. > > But for the sake of clarity to those that may read this thread later… > > The rigs in question in this part of the thread are the K4. > > Every component of my station is bounded and grounded per K9YC’s > publications. My antennas are effectively common mode choked both at the feed > point and at the entry point to the shack (the latter demonstrably reduces > received noise at my noisy QTH). > > I am unaffected by RF at the operating position in the sense that I don’t get > burned and none of my peripherals (such as a PC and monitors, for example) > display any evidence of RF at all. The only issue here is what appears to be > RF feedback getting into the audio when using a CM-500 plugged into the rear > panel mic jack and, as I discovered later, a D-104 plugged into the front > jack. Neither mic is shielded and neither uses twisted-pairs in their cables, > so it is possible that at least some of the problem lies not with the station > but the mics themselves. Quite interestingly, another mic didn’t exhibit the > problem here at this same station. > > So is there RF at my operating position? Well to state the obvious, I guess > there must be at least a little or else this would not happen. But until I > find where it’s coming from, a "band-aid” (common mode choke) is an > appropriate way to continue safe operation. This band-aid may also be > appropriate to augment components that can’t readily be fixed otherwise. > > My comment about Elecraft looking at the radio for RFI issues was solely in > response to another post in this thread where it was stated that Elecraft was > ALREADY looking into the rear panel mic jack for RFI, which made me wonder if > there was a known problem. IF that is true, then maybe looking at the front > panel jack may be advisable. Otherwise I agree it’s not up to Elecraft to > work out RFI issues at an individual’s station. > > 73, > Dave - N5DCH > > > > >> On Nov 24, 2021, at 8:11 AM, Bob McGraw <[email protected] >> <mailto:[email protected]>> wrote: >> >> Running my K3S, KPA500 and working 160M - 6M at 500 watts, using either a >> mike into the front of the radio, or my headset into the back, I experience >> NO RFI issues. I don't have any toroids on any cables either. I also run >> digital modes with a single USB cable between the computer and the radio. >> All of these inputs/output stay connected all of the time. >> >> As to using toroids, refer to the work that Jim, K9YC has written and >> published. If you experience RFI and use toroids to resolve the issue, you >> have only put a band-aid on the wound. I suggest looking at the antenna >> system, feed line system, and bonding of equipment cabinets to reduce RF at >> the operating position. >> >> I don't see this as a need for Elecraft to look at the radio for RFI issues. >> To many hams use the K3 series successfully without RFI issues. >> >> 73 >> >> Bob, K4TAX >> >> >> On 11/23/2021 9:28 PM, [email protected] >> <mailto:[email protected]> wrote: >>> I also had RF problems with the CM-500 plugged into the rear mic jack. The >>> solution I?ve implemented so far was to wrap about 13 turns of the CM-500?s >>> cord around a #31 toroid. It both shortened the cord which was way too long >>> for my shack and eliminated the RF problem. A two-for-one solution.;-) >>> >>> On rare occasions I like to use my D-104 mic in the front panel jack. It >>> too is adversely affected with RF issues. As soon as I get a moment I?m >>> going to try wrapping it?s cord around a #31 toroid and hope it works as >>> well there as with the CM-500. >>> >>> I hope Elecraft is looking at the front panel mic jack as well as the rear >>> when looking at solving the RF issue. >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> <http://mailman.qth.net/mailman/listinfo/elecraft> >> Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm> >> Post: mailto:[email protected] <mailto:[email protected]> >> >> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >> Please help support this email list: http://www.qsl.net/donate.html >> <http://www.qsl.net/donate.html> >> Message delivered to [email protected] <mailto:[email protected]> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
