I’ve only noticed a thump with a piece of equipment which has a power supply when it turns on at a line voltage peak. On the occasion that it turns on at a line voltage zero crossing, it makes no noise at all.
Chuck KE9UW Sent from my iPhone, cjack > On Jun 27, 2018, at 2:10 PM, Bob McGraw K4TAX <[email protected]> wrote: > > Seems that the AC line supplying the equipment has a rather high impedance > thus allowing the voltage to suddenly drop under the dynamic load and then > surge to a higher than normal value. > > A dedicated 120V and/or 240V service should be considered for the station > power. > > Laser printers do draw considerable power when they start. > > Bob, K4TAX > > > Sent from my iPhone > >> On Jun 27, 2018, at 2:00 PM, John Simmons <[email protected]> wrote: >> >> My Astron RS35 does the same thing under the same conditions. >> >> -John NI0K >> >> Matt NQ6N wrote on 6/27/2018 1:20 PM: >>> My KPA500 makes a noticeable hum/thump when the laser printer that is on >>> the same circuit draws a lot of current. >>> >>> 73, >>> Matt NQ6N >>> >>> On Wed, Jun 27, 2018 at 12:58 PM Jim Brown <[email protected]> >>> wrote: >>> >>>>> On 6/27/2018 10:37 AM, Richard Wade wrote: >>>>> If I had to venture a guess, I would say that somehow the unpowered >>>> KPA500 >>>>> was picking up noise on the shack wiring. Very strange. Is that >>>> possible?? >>>> >>>> It is if equipment in your shack is not properly bonded together, and to >>>> house grounds that are also properly bonded together. Study N0AX's >>>> recent ARRL book on the topic, to which I contributed, or the slides for >>>> a tutorial talk I've done at several hamfests. >>>> >>>> http://k9yc.com/GroundingAndAudio.pdf >>>> >>>> 73, Jim K9YC >>>> >>>> >>>> ______________________________________________________________ >>>> 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] >> >> ______________________________________________________________ >> 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] ______________________________________________________________ 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]
