Cookie has it right. It seems to me another issue is that many of the knobs have tight threads. Not terribly tight, but requiring more torque than I normally see on such a small screw. I had some like that on my first set. Lube didn't help. That makes it difficult to tell how hard they are binding against the control shafts.
Also, I wondered if the fact they were tight wasn't due to a slightly undersized hole, so the set screw acted like a wedge pushing outward on the surrounding area as it was screwed in. A wedge like that can exert huge force on the knob even though it's not very hard to turn. That could be the source of stress cracks before the knob was even tightened. The Aptos folks have been very clear for a long time that they got a bad bunch of knobs and have replaced them as quickly as cracks have been reported. So far, my second set, received almost a year ago, has been fine. Ron AC7AC -----Original Message----- Posts like this are no doubt well intentioned and good advice in general. For these knobs with built in stress cracks normal care is not adequate. Use the short handle for leverage, just tighten barely enough that the knob does not slip on the shaft, expect the knob to fail while you are adjusting the knob at some point in the future. If can keep spare knobs on hand. Elecraft are taking steps to get us better knobs and I am confident they will succeed soon and do something that is appropriate, but it takes a while to accomplish these design changes. I am sure they will let us know soon. But don't assume that those of us who have had failures are ham-fisted klutzes who don't take normal precautions. That could be the case sometimes, but certainly not the general situation in this case. Willis 'Cookie' Cooke K5EWJ ______________________________________________________________ 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
