So brought the K3 in to work this morning to our lab area where we have static benches, blowers, wrist straps etc. and opened it up. Sure enough, the T4 transformer was pretty crispy looking. My boss who is also an avid ham (dream job setup :) ) then sprang into action. He removed the transformer, counted the turns, removed the old wire, found some new magnet wire of the proper gauge, rewound the toroid, and replaced both it and the straight through portion (which had gotten pretty hot from the proximity to the core.) Prior to stripping the burned turns off of T4 we looked at it under a microscope and saw that the windings had burned open in one place, effectively acting as a fuse of sorts. There didn't seem tpo be any other parts, connectors, or board traces that looked to have been stressed. I brought the radio home and hooked it up to a dummy load and a reasonably accurate external wattmeter. It seems to be fine, both on receive and transmit.
I was hoping there was a built in SWR bridge cal procedure, but I didn't see anything like that in the manual. The SWR values reported though seem to match the LP-100A I am using externally pretty closely. I did try to follow the Wattmeter calibration and ran into some confusion on the procedure as written in the manual. I think I was able to puzzle it all out except for one item - how do you change the config menu item from CONFIG:WTMR LP to CONFIG:WTMR HP? It doesn't seem to change just by having the tune power changed to 50 watts, so I am at a loss on how to change it. So perhaps my K3 is now alright again, although I would appreciate any other comments on other things to check or calibrate. And thanks to all on the list who helped me out. After this the next project is to fuse the DC supply cables to my DC blocks with some rationally small value of fast blow fuse :) de Mike/KE0MF ______________________________________________________________ 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]
