[Elecraft] Not necessarily an Elecraft subject!

[Ron D'Eau Claire]

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<capobs1 at bellsouth.net> 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
>