I do the same as Bob with a Vibroplex I "inherited" when my buddy's XYL gave it to me when he became an SK. You can see it at work with its original owner, complete with cable clamp, at RCA station KPH in the top photograph on this page:
http://www.radiomarine.org/historic-5.html That Vibroplex was the second one LR (the original owner) had, purchased in the early 1960's. (LR had served in the Merchant Marine through WWII). Doing some research into this key I discovered that, for reasons never explained to me, Vibroplex made a number of bugs with a very thick pendulum spring compared to earlier (and, I believe, later models). The impact of that thick pendulum was to cause the pendulum to vibrate *very* fast. Not even all the weights Vibroplex sold could bring its dit speed below 30 WPM - way too fast for commercial or normal Ham use. Hence, the heavy weight. Some Vibroplex keys with thinner springs are controlled nicely using just the standard Vibroplex weights. The disadvantage of the cable clamp is that it gives the key a very heavy 'feel'. There's a *lot* of inertia in that weight which the thumb has to overcome to start dits. An option is to extend the length of the pendulum. I have "tamed" LR's key by adding a large alligator clip to the end of the pendulum, positioned so the jaws gripped the top and bottom of the bar so as to not interfere with the damper. Extra weight from a few wraps of solder around the end or a nut threaded onto the end of the alligator clip will slow it further. That brought the pendulum speed well down below 20 WPM without adding lots of weight. Some fellows have used clothes pins and other additions to accomplish the same thing. There are a couple of commercial products available. One is the "bug tamer" - an extension to the pendulum (adding length slows it down much more easily than adding weight). Another is the "Vari Speed" that is a mixture. It is shown here: http://www.visradio.com/cata/vib-vs.html It works well provided you tighten the screws enough so that it doesn't suddenly start to flop about in the middle of a transmission, Hi! But I still prefer the cable clamp like LR did. It works very well and, for me, it's a nod to "tradition" that LR started half a century ago with that particular key. Ron AC7AC -----Original Message----- If you can't find one, try using a 1/4" wire rope clamp with the legs pointing "up". It's easily adjusted but stays in place when the nuts are hand-tightened. I use one on an Original I've set up for slower speeds. I lined the saddle of the clamp with a piece of vinyl electrical tape so it doesn't scratch the shaft. Bob NW8L On Sat, Aug 22, 2009 at 6:27 PM, James Harris<[email protected]> wrote: > Good evening, All. > > I recently acquired a Vibroplex "Original" with the idea of learning to use it attached to my K3/100 [S/N 2802]. I need to slow it down until I can get the "gist" of it. I can now work at 18-22 wpm with my Iambic. But I wouldn't dare try to get on the air even at the "bugs" slowest speed adjustment which is in the range of 30 wpm. > > I would like to buy, lease or borrow a Varispeed {for a round shaft] until I can get up to speed with my new toy. They are no longer available from Vibroplex. > > I'd like to hear from anyone having such a device. > > Thanks & Best 73. > > Jim......... > WA4NTM > ______________________________________________________________ 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
