Sometimes older answering machines can do that. Also some digital power supplies can do that. I would try unplugging things or turning off circuit breakers to see if you can make that noise go away. I have heard similar noises.
Sent from my iPhone this time > On Nov 15, 2014, at 3:42 PM, Dauer, Edward <eda...@law.du.edu> wrote: > > Anyone have an idea where and how I might begin tracking this down . . . > > KX3 (indoors with a Buddipole) has a signal every 18 Khz across almost all of > the HF spectrum, worst on 15M. It also appears on the PX3 display - in all > the same places. On both AM and CW it sounds like a buzzing, with about a 1+ > Khz bandwidth.. > > The signal level changes on the KX3 as expected with PRE and ATT cycled. On > the PX3 display, PRE and ATT change the base level but not the absolute value > of the peaks. > > Here's the odd thing - the audible signal disappears from the KX3 when the > antenna is removed, but it does not disappear from the PX3 - where, again, > the base level changes but the magnitude above base level does not. And it > remains in the PX3 display even when the I/Q cable is removed. > > Neither the KX3's NB nor NR change anything. > > The KX3 is running from batteries, so it's not the outboard power supply. > Neither is it the PX3's wall wart, since the signals are present in the KX3 > when that supply is removed from the source. > > Unfortunately it will be a while before I can move the equipment to another > location to see if that matters. In the meantime, anyone know a signal > source with harmonics at 18 Khz? > > Tnx, > > Ted, KN1CBR > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to gerrylear...@icloud.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
