[CW] Bug Adjustments

[Matt Cline - Westcott House Foundation]

David:

Yes, that method of bug adjustments usually works very well. The theory (as 
best I can determine) for the single non-moving weight at the close end of 
the pendulum seems to produce a relatively consistent minimum mass to the 
pendulum and allows for a more consistent dot creation with a consistent 
right-paddle throw. Having and moving only a single weight around changes 
the period and momentum of the dot pendulum so that its contact with the 
dot spring is slightly different every time. Its a really problem on slower 
speeds.

I essentially do just that, although I never got it off the article you 
describe. I have one weight about 1/2 way along the standard pendulum. Then 
I got one of the "bug tamer" attachments that extends the pendulum beyond 
the damper structure. A weight on that extension is used to adjust my 
speed, as I tend to still go pretty slow (relatively speaking).

However, to be honest, I still had to make a key interface to my radio that 
cured a problem I was having with my bug and my FT-100D. Most of the folks 
I spoke to who use bugs say a simple adjustment would work just fine, but I 
never got it to work. The problem was that my Vibroplex Blue Racer 2000 and 
several other bugs I was using created a scratchy connection when creating 
a dot and somewhat when creating a dash. The nature of a bug is such that 
the contacts don't make definitive sharp contact. In electronics terms, it 
"bounces" a little. So I made a small 12 volt electrical relay interface. 
My bug activates/deactivates the relay and the relay control the CW on/off 
with my FT-100D. It worked perfectly. Each time I throw the bug, I get a 
razor sharp dot or dash. I have a good fist, so I have had many of my 
fellow CW'ers tell me they thought I was using an electronic keyer. So I 
use the bug as my code generation interface, but I let the relay be the 
interface to the rig to clean up the problems of a modern extremely 
sensitive electric rig with the "eccentricities" of a bug. The relay does 
not take ANYTHING away from your code generation. Garbage in, garbage 
out...Good code in, good code out. Its just cleans up the actual dots and 
dashes attack and decay qualities. If your adjustment does not work with 
the weights, try a simple relay interface. You will be amazed at what a 
difference it makes.

Hope to hear you on the air soon.

73'

Matt, KB8WFH


Someone sent me an article from a radio magazine - unfortunately I don't
know which one, but it was an article about adjusting a bug.

One of the things it says, that I haven't been doing is the method of speed
adjustment with two weights - he says to leave one weight "all the way" out
at the end of the pendulum, and adjust the key by moving ONLY the inner
weight.

This is the opposite of what I've been doing, and I it might be possible
that I asked for instructions on this over the "circuit" and received a
backwards mental picture of what I was supposed to do.

Here is the article - and do you have any comments?  Is this a better
method?

I have to admit that having the whole arm of the key vibrate with a mass at
the end sounds like it would produce a better clearer dot.

73

David Ring, N1EA

CLEANING  AND ADJUSTING SEMI-AUTOMATIC (BUG) KEYS

'DOC' WESCOMBE-DOWN, VK5HY/ VK4CMY, believes that a straight hand keys and
bug-keys are the only true Morse senders around - the electronic keyers and
keyboard Morse generators have dehumanised the basic skill of Morse code,
which is the making and spacing of characters, numbers and symbols correctly
by hand".

While I guess that this is today a minority opinion it is true that
"seasoned CW operators take pride in the upkeep and adjustment of both
straight and bug keys, this never being seen as a chore but the key element
in the formation of Morse." In Amateur Radio, July 1994, ppl 1-12, VK5HY
provides detailed information on maintaining and adjusting semiautomatic
keys, and the following information has been abstracted from his article:

He stresses that no two operators key exactly the same way and that the most
important aspect is correct adjustment of the keyforsending well-formed dots
(dits). Again, just as a person?s handwriting changes so does the 'feel? of
the key change, so that you need to be able to adjust it to suit your
current keying. Fig 12 shows the usual adjustment points of most makes of
semi-automatic keys. Note that some experimenting with the following
adjustments may be needed.

Adjust both the left and right trunnion screws so that the vibrator arm
(pendulum) lies perfectly straight and butts lightly against the damper
wheel. This sets the initial 'hands off' key position.

Slide the speed weight(s) on the vibrator arm to the end position giving the
slowest dot speed. Tighten the weight(s) ensuring they do not contact the
damper wheel.
Hold the flat thumb paddle in the constant dot position and adjust the left
trunnion screw so that the vibrator dot can move to the left about 0.4mm
(1/64 inch). Use a small scale rule to check. Then tighten the left trunnion
screw.
  Hold the paddle for steady dots and allow the vibrator arm to stop
vibrating. Now adjust the dot contact screw (on the dot post) so that the
contact just makes firm connection with the vibrator dot, giving steady tone
from your monitor. Tighten contact screw and release paddle.

To check dot adjustment, hold paddle to activate string of dots - there
should be at least 40 dots for each paddle movement, if necessary
repositioning dot contact screw to obtain this. When the vibrator arm stops
oscillating, the vibrator dot should come to rest lightly touching contact
screw.

With two speed weights, to speed up dot rate, slide the innermost weight
towards the paddle end. Always keep the outemost weight at end of vibrator
arm regulating dot speed with innermost weight.

For dash adjustment, position dash contact for a lateral movement of 0.4 to
0.8mm (1/64 to 1/32 inch). Typically, thickness of a sheet of typing paper
or a business card. Movement is a matter of personal preferei~ce, but the
smaller the spacing the better the feel of the key.

Adjustment of spring tensions is a matter of personal preference. Typical
about one third of the tension available. The less tension, the easier the
feel. It depends on whether you have a 'light' or 'heavy' arm action.

Some users have been seen to use finger touch operation similar to that
preferred by some users of electronic keyers. However, the bug key was
developed to prevent 'glass arm' in protracted operation.

VK5HY suggests "set the key side on to you (i.e., vibrator arm longways to
the front
of your body) located directly infront of the shoulder of your non-keying
arm and rest
the non-keying forearm parallel to the key. Also rest the keying forearm
flat on desktop so your body weight is taken evenly by both forearms. The
key is now operated by wrist rotation towards (dashes) and away (dots) from
your body front. This posture immobilises whole arm action and encourages
rolling of the wrist - just as with a straight key, wrist action produces
rhythmical Morse, not 'nerve Morse'. Once this basic action is acquired, the
bug can be repositioned to suit individual situations."

On the subject of key maintenance, VK5HY recommeds periodic inspecton of the
condition of gold or silver contacts. They should be clean and bright. Place
clean typing or copying (bond) paper between the contacts and pull it
through several times to wipe the contacts. Use switch contact cleaner also
but no, repeat no, matchbox striker paper, wet 'n' dry paper, or any
abrasive cleaner such as Brasso or Silvo. These should be used only when
attempting to resurrect badly pitted and burned contacts although it is
better to have new contacts or re-plate old ones. If you do wish to
resurrect pitted contacts use (1)  very fine emery paper: (2) very fine
wet'n'dry paper; (3) crocus cloth or toothpaste on a polishing cloth; (4)
bond paper.

To remove leftover polishing debris, use cotton buds and rubbing alcohol or
petrol.
Clean the areas thoroughly. Don't use CRC, or sewing machine oil, etc on a
bug as these attract lint and dust. Use tiny dabs of silicone lubricant at
pivot points. When not in use keep the key in a dust cover.

-30-

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