My KPA1500 Power Supply is making a noise that has gotten progressively
louder over time when I transmit. It sounds like a hissing (but it is not arcing) when I transmit. The noise is modulated by SSB speech or CW or digital modes keying, louder at higher power levels now during the CQWW WPX Phone contest. I am pretty sure it is not RF getting into the Power Supply. I have followed K9YC practices of bonding the K3, KPA1500 Power Supply and RF decks to the ground bus. All cables going into and between are wound on snap on or toroid ferrites. Has anyone else run across this? I plan to open up the power supply and check for loose parts and do some more testing after the contest. -- Thank you! David Needham, AA4VT (formerly K4AJA and K8AJA) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Not heard here, although my KPA-1500 gets fairly heavy use. Power
supply is on the floor, which no doubt helps with noise. 73, Pete N4ZR Check out the new Reverse Beacon Network web server at <http://beta.reversebeacon.net>. For spots, please use your favorite "retail" DX cluster. On 3/27/2021 11:06 AM, David Needham wrote: > My KPA1500 Power Supply is making a noise that has gotten progressively > louder over time when I transmit. It sounds like a hissing (but it is not > arcing) when I transmit. The noise is modulated by SSB speech or CW or > digital modes keying, louder at higher power levels now during the CQWW WPX > Phone contest. > > I am pretty sure it is not RF getting into the Power Supply. I have > followed K9YC practices of bonding the K3, KPA1500 Power Supply and RF > decks to the ground bus. All cables going into and between are wound on > snap on or toroid ferrites. > > Has anyone else run across this? I plan to open up the power supply and > check for loose parts and do some more testing after the contest. > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by aa4vt
Regarding placement of the KPA1500 power supply.
After repairing and maintaining residential home computers professionally for several years, be advised that floor placement will allow 5X the dust to be sucked into the unit. Units with air flow in and out are like vacuum cleaners. I recommend raising the unit, even if only a foot or two, to reduce dust intake. Units on the floor were packed with dust as compared to units on desks. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
I used to maintain computers used by farmers. I’m surprised they didn’t plant crops in them. There was enough soil there. Floppy disks (this was a long time ago) were unusable due to the abrasive action of the dirt.
Victor 4X6GP > On 28 Mar 2021, at 4:24, Steve Hall <[hidden email]> wrote: > > Regarding placement of the KPA1500 power supply. > After repairing and maintaining residential home computers professionally > for several years, be advised that floor placement will allow 5X the dust > to be sucked into the unit. Units with air flow in and out are like vacuum > cleaners. I recommend raising the unit, even if only a foot or two, to > reduce dust intake. Units on the floor were packed with dust as compared > to units on desks. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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