Re: [Elecraft] K3 Audio our artifacts
Jim Brown wrote: On Mon, 02 Mar 2009 18:58:58 +, Brian Alsop wrote: I'm wondering about a UPS supply that's attached to the computer. Do they only kick in when power goes out That is nearly always how they work. BUT -- if the transformer is The sort of UPS that would be used by a data centre would normally always use the inverter, the argument being that it avoids mains transients (and, presumably, gives a cleaner switch over). -- David Woolley The Elecraft list is a forum for the discussion of topics related to Elecraft products and more general topics related ham radio List Guidelines http://www.elecraft.com/elecraft_list_guidelines.htm __ 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
Re: [Elecraft] K3 Audio our artifacts
David is correct. You really need to look hard to find an inverter type of UPS in the consumer market. All of the consumer grade UPS's I know about (APC, Tripp-lite, etc) are switching types and have been known to cause problems. David Woolley (E.L) wrote: Jim Brown wrote: On Mon, 02 Mar 2009 18:58:58 +, Brian Alsop wrote: I'm wondering about a UPS supply that's attached to the computer. Do they only kick in when power goes out That is nearly always how they work. BUT -- if the transformer is The sort of UPS that would be used by a data centre would normally always use the inverter, the argument being that it avoids mains transients (and, presumably, gives a cleaner switch over). -- R. Kevin Stover, ACØH __ 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
Re: [Elecraft] K3 Audio our artifacts
On Mon, 2 Mar 2009 18:23:57 -, Dave Hachadorian wrote: would guess that the headphone output is expecting a low Z (~16 ohm?) termination, and your sound card has a high Z in. Try a terminating resistor across the headphone jack in parallel with your sound card. No, termination has nothing to do with it. It's either power line hum/buzz or 60Hz leakage flux from a power transformer. 73, Jim K9YC __ 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
Re: [Elecraft] K3 Audio our artifacts
On Mon, 02 Mar 2009 18:58:58 +, Brian Alsop wrote: I'm wondering about a UPS supply that's attached to the computer. Do they only kick in when power goes out That is nearly always how they work. BUT -- if the transformer is energized, there will be a field. So it depends on how that particular device works. Have the opposite problem with earphones clean but line out polluted by third and other odd harmonics. That's produced in the line out transformer because there's 600 ohms in series with it and the output driver. The mod fixes that by reducing the resistors to a much smaller value (50 ohms, I think). 73, Jim Brown K9YC __ 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
