A follow-up Got back to the radio after mulling the comments this weekend regarding this asymmetric knob issue and... the felt hiss issue. Lost some sleep over it as that's the time I seem to best come up with creative things.
So.. I made a plastic feeler gauge of the pointy bevelled end of a Plackers flosser stick as that won't scratch the paint. I marked where the gauge stopped under the narrow end of the A knob and then compared it to the other side 180 degrees away. A marked (no pun intended) difference. I then put that A knob on the B Vfo and did the same procedure with a new flosser stick. and indeed there was a slight difference here as well but in the opposite direction. As the knob did not wobble on either VFO but tracked poorly, I surmised the shaft does not innately follow the straight path when tightened. So I loosened both nuts and this time applied a small amount. of pressure on the nut driver away from the low side. That resolved the problem. I then did the same with VFO B's shaft though it wasn't presenting an issue. I do try to keep symmetry in all things... Issue Resolved. Now as to the hiss. Some really interesting ideas, especially getting SWMBO to give up her softer felt in exchange for a nice dinner cooked by HWMS. But that doesn't apply here so the idea of the Fender washer was a worthy possibility & I was prepared to get two Nylon washers to see if some combination f the 2 felt washers & 2 nylon ones would work well but then I thought about it while tossin' & turning last night & it dawned on me: Wrap the felt washer with teflon piping tape like it was a toroid transformer. So I ran the tape through the felt washer and did so all the way around till the washer had no felt showing but the hole was still there. I put that in place and the give was still there because of the felt doing its job and it was silent because of the teflon . Wala... Success on all counts! Now to get to the post office to send out a TenTec VFO I just sold to apply the $ for more K3 goodies & get a present for Mom who turns 99 on Christmas Eve. Thanks for the idears, they got me to the solutions! I'll have more questions as I still have to learn how to operate the K3 & I have yet the sub Rx on its way & the transverter interface. 73, Gary KA1J > Hi Patrick, > > Indeed there was a third felt washer with mine too. Presently I do > have it installed with the 2nd one in place. My knob wasn't loose > though, it was quite firmly attached once tightened. When I first > felt the knob rotate properly for say, 200 degrees of rotation & then > bind a little for the remaining 160 degrees (making up numbers here > but fairly accurate), I removed the knob and saw a little circular > scratch on the clear plastic cover where the edge of the knob had > scored it. I then put the knob back in place & put the K3 on end & > looked from underneath along the front plane & saw the knob was > resting with a slight tilt. Again though, this knob wasn't loose, it > was firmly attached. > > I removed the knob & put the 2nd felt washer on top of the first to > get it off the plastic and add some tension and then tried it again > but when rotating the knob, I could hear a felt on felt sound like > scuffing two chalkboard erasers face to face. Not the end of the > world or anything but VFO B makes only the faintest of hissss from > the felt and B acts perfect. > > The Best tension I can get for the A knob isn't as good as the VFO B > which feels darned good to rotate. I did rotate each of the shafts > before assembly to be sure they were OK & they both rotate with zip > friction. > > I could forego any friction at all & it would be fine & easy to > rotate but it would be a constant annoyance when I bump the VFO & > then be moved away from a frequency I'd narrowed in on. Since I will > forever be using VFO A, I do need it to feel natural. > > Gary > KA1J > > > Well, I'll jump in here. I had the same problem a few months ago when I > > assembled S/N 1889. The VFO A knob was way too loose no matter what I did. I > > had followed the instructions and installed one (1) felt washer under both > > the VFO A and B knobs. The B knob was fine. The A knob couldn't be adjusted > > to my liking. Then I noticed I had an extra felt washer (i.e., a total of > > three were included in the package). I added the second washer and life is > > good. I have it setup so I can spin it and get a nice smooth run (maybe 6 or > > 8 turns) as it freewheels but yet for my taste it's not too loose. > > > > Like everything else of course it's all a matter of taste. Two washers > > worked for me. If it was an accident (they included too many) then it was > > fortuitous in my case. If by chance you have a third washer install it and > > life will be good. > > > > 73/Patrick > > W7TMT > > > > > > > > _______________________________________________ > > 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 > > > > > _______________________________________________ > 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 > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. 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