I suggest one check the 240V wiring to confirm all connections are tight and solid all the way from the main breaker panel to the outlet for the amp. This includes L1, L2, Neut, and Ground. Also I would make sure there is a solid ground between the PS cabinet and amp cabinet.
Also , since recent issues are reported as new for 10M, make sure the station ground ( if one is used) is not near 1/4 wavelength on 10M. That’s about 8’ or so. 73 Bob, K4TAX Sent from my iPhone > On Dec 16, 2019, at 4:28 PM, Chris Codella, W2PA <[email protected]> wrote: > > Scott, > > I noticed the same thing this last weekend, having not been on 10 much since > getting the amp. But I found the noise to be quite variable. It doesn't > always occur. When it does, it appears suddenly, out of the blue while > operating. > > Sometimes I could make it go away by turning off the power, waiting a while, > then restarting. I also got it to stop a couple of times by sending a single > "dit" while in operate mode. Quite strange. I'm trying to get more data but > it does seem to be an intermittent thing and hard to replicate. > > This noise didn't affect any band below 10m but appeared very broad-banded > above, using an SDR receiver. > > 73, > Chris, W2PA > >> On 12/14/2019 4:43 PM, K9MA wrote: >> I guess it just shows how little I've been on 10, but I've had the KPA1500 >> for over a year now, and I just noticed that when I turn it on, my noise >> floor on 10 goes up about 3 dB. (And that's from an urban noise floor.) It's >> pretty flat over much of the band, not typical switching supply noise. Has >> anyone else experienced this and found a cure? (Other than using the old amp >> tube.) >> >> 73, >> >> Scott K9MA >> > > ______________________________________________________________ > 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] ______________________________________________________________ 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]
