Merv, if you're suddenly getting hash from two formerly-clean switchers, I'd suspect something else, such as a bad mains ground on the circuit feeding the supplies or a change in the rig's grounding system that is now introducing some sort of a "ground loop" return.
Have you made any changes to your antenna situation lately? If feeding with coax, are the shields intact and properly terminated at the rig? After over 50 years of fixing electronics, I've yet to find two similar failures in separate gear that were coincident, no matter how often I've tried to convince myself I was finally experiencing the first time. It's always something in common to both. As for power supplies in general, my linear Astron 20 handles my K3 FB. (I don't try to crowd out an extra 1/10 of an S-unit above 100 watts by running the power control "wide open" keeping the demand comfortably within the Astron's 20 amp ICAS ratings on CW/SSB. If I want to run a 100% duty cycle mode such as RTTY, I back down the power.) The linear supplies may be heavy, but I don't take mine back-packing (the extension cord would weigh more than the supply if I did ;-) So it sits under the operating desk where I don't care how heavy it might be. Ron AC7AC -----Original Message----- The past couple of days I have noticed the noise level on the K3 has gone up a couple of S units and on 20 meters and there were tunable hash signals. I started to try and find the problem and using another receiver I find the Astron SS-30 is generating all sorts of noise. I have used this supply for some time and have not noticed the noise before. I drug out an old backup supply MFJ-4245 and behold it also has a lot of tunable hash signals on 20 meters. Wonder what supplies are being used with the K3? Or if anyone has had luck on cleaning up the switcher supplies like the Astron? I suspect it could be due to age and caps going bad, the supply has been in use for 8 years. There are no locally available parts so before I try and recap and order ferrites etc like to know what works if anything. Thanks Merv KH7C ______________________________________________________________ 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
