Wondering if it's possible in any practical sense for the windings to change on their own, or with vibrations from mobile/portable operation.
Not just for the K3, but any toroid of similar construction and mounting. ================ We used to go to Baskin-Robbins for "hand-packed" ice cream because everyone knows it tastes better. ;-) >>We carefully hand-adjust the windings after the toroids are mounted. ================ [Elecraft] K3 Toroids: Why some have uneven turns spacing (It's intentional!) wayne burdick n6kr at elecraft.com Mon Nov 19 19:52:35 EST 2007 Please DO NOT adjust the turns on any of the toroids in the K3 to make them "look nicer" :) In some circuits, we need to hold 2% or better tolerance on inductances to meet filter passband cutoff or ripple criteria. We carefully hand-adjust the windings after the toroids are mounted, because it's not practical to control them to this tolerance at the winding house. A lot of very expensive test equipment is brought to bear on this as we sweep for best return loss (lowest SWR) and the required passband shape. Having the turns spacing slightly irregular may not look as pretty, but trust me, they're where they need to be. This is one reason for the large-gauge wire on toroids in the low-pass filters. And it has no significant impact on their self-shielding characteristics in our applications. We'll be adding a note about this to the assembly manuals. 73, Wayne N6KR _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
