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Chapter 9 - Part II
Contents Chapter
11
In Chapter 9 the regular "straight" keys were discussed at length. Here we look at all keying devices.
These may be classified as:
For the handicapped several kinds
of keys have been devised to be operated by breath pressure on a diaphragm
or piston, etc. Some of the interesting recent designs take advantage
of solid-state circuitry using such things as a) the interruption of a
light beam by a finger tapping in front of a photo-sensitive cell, b) the
change of capacitance or resistance produced by moving a finger to
approach or lightly touch a fixed metal pad, c) the tone of a human voice
humming in Morse code within the range of a tiny microphone, and
other possible means to control the keying. How does one classify
such devices?
OTHER KINDS OF MANUAL KEYS
The "DOUBLE SPEED" KEY
- "SIDESWIPER"
Just when the first "sideswiper" came into existence does not seem to be known. It is based on the idea that sidewise hand movements should be easier and perhaps faster than up and down movements. According to records found and graciously supplied by Jerry L. Bartacheck, KD0CA, the J. H. Bunnell Co. patented their new "double-speed " key in 1888, and claimed that it was developed to overcome telegrapher's paralysis or "glass arm". Today this type of affliction is called "carpal tunnel syndrome". Those who used this new key did find its claims to be true - that sidewise movements are much more comfortable and natural, and that it did prevent or greatly reduce the risk of glass arm. This key for a time became popular and was often called a "sideswiper", and sometimes a "cootie key". However, Bunnell's key was rather expensive and easy to imitate.
To use it, the operator used his thumb and forefinger to move the paddle of the key lever alternately from one side to the other -- each direction closed the circuit, whether moved to the right or to the left. In this way he formed the successive dits and dahs for each character. For example, If the operator made the first element of a character to the left (L), whether it was a dit or a dah, its next element was made to the right (R), and so on, alternately so that his pattern of movement was L-R-L-R-L-R .. . . or R-L-R-L-R-L . . .
This back and forth motion often tends to lead to a sort of peculiar rhythm of its own, betraying the use of a "sideswiper".
A few operators, troubled with "glass arm" found relief simply by turning their straight key around 90 degrees so it could be used with a one-way sidewise motion. (This use is easy to do with a bug or keyer which already uses sidewise motion.)
Commercially made double-speed keys were
relatively cheap compared to the Vibroplex, and it was quite easy to make a
good home-made one. No wonder that it became popular in wireless
operations, especially among hams,
for some years. (It does not seem to have been used much by landline
telegraphers.) Perhaps its novelty was as much an attraction as its claim
for higher speeds and lowered fatigue.
The double-speed key may have led
later to the idea of the semi-automatic key, whose first good commercial
version, the "Vibroplex" was introduced in 1904, and soon began to
be widely used by commercial telegraphers.
Of passing interest in 1926 was a
similarly connected key having two pushbuttons, like typewriter keys or
pushbuttons, to be used with two fingers, called the "Cricket" by its
manufacturer. The keys were to be used alternately to form the characters,
as with the "sideswiper". It never became popular.
The "BUG"
Historically the Martin semiautomatic
key, introduced in 1906 as the "Auto" and later as the "Vibroplex" - commonly
called a "bug" - is listed here second because of its greater mechanical
complexity and difference in use.. The patented Vibroplex, by making
dots automatically (by the sidewise vibration of its elastically mounted
arm), relieved much of the operator's effort (although he still had
to form the dashes manually), and increased his speed potential, while
reducing the risk of "glass arm" (by sidewise movement and division of
labor between thumb and fingers).
In its various models it became very popular and has been widely used up to the present time. There have been many imitations, a few of which also produced automatic dashes. Normal (right handed) models formed the dits automatically with a right-wise movement of the thumb and the dahs manually with a left-wise motion by one or two fingers against a paddle assembly. A few designs produced by a few manufacturers provided automatic dahs with by a second vibrating arm.
On the Australian land-lines bug-keys
were known as "jiggers". Those issued by the Sydney GPO Telegraph
Office in 1946 had 3 knobs, two of them controlled separate swinging arms,
one for automatically forming dits and one for automatic dahs and
the third for manually controlled dahs. The knobs could be positioned
at either end of the base-plate for easy use by right or left handed people.
I have no information as to how these were used.
USING A BUG
A "bug" should not slip on the table,
and its paddles should be about 2-1/2 inches above the tabletop.
Most teachers recommend a light touch, pivoting the hand on the knuckle
of little finger and using as combination of finger action and rolling
wrist-motion. (Long-time speed champion Ted McElroy, however,
said the wrist and elbow should be off the table, and a full, free swing
of the arm used.) We may suspect several different styles are equally
satisfactory. (It has been suggested that by holding a pencil in
the same hand while sending will help one learn to relax.)
Bug sending should duplicate good hand-key sending. Handle it easily. Do not grip its paddles, but only allow the fingers or thumb to touch the side you are pressing on -- not touching the other side. When a bug is used for radio work there is a tendency to make the dits relatively too light. As compared to telegraph landline sending, radio requires a heavier style to put the signal through static and interference, and a heavier key will help do this. So be sure to set heavy enough dits that they are not likely to be swallowed up by moderate static or interference.
Setting the Adjustments of a Bug
Like all keys, bug adjustments are
a highly personal matter, varying from one operator to another. They
are also sensitive to the range of speed. For example, a bug set
for 35 wpm operation will do poorly at 18, and vice-versa. -- Remember
the rule: NEVER readjust another operator's bug!
Hugh S. Pettis, K3EC, recommends the following as optimum bug settings:
Robert. R Hall W9CRO recommends: (Some adjustments are interactive.)
SENDING WITH A BUG
Key smoothly and easily with a minimum
of effort. Let the bug do the work - you just control it, with the
arm resting on the table, touching the paddles loosely (lightly) between
thumb and forefinger. Control it without much motion of the hand
or fingers. A slight twist or roll of the wrist will change from
the dit to the dah side. Relax and enjoy it. Don't
bat out the dits and dahs out with thumb and forefinger so widely separated
and so hard that it tends to push bug around.
There is a marked tendency among
some bug users to set the dits too fast relative to the hand- formed dahs
and spaces. Hand-formed spaces tend to become too long in proportion.
The result is often a choppy sounding code or to signals which are certainly
readable, but tiring to listen to and read. Katashi Nose KH6IJ points
out that "at high speed one cannot put much force on the paddles."
He also said that "If you move your whole arm, the law of inertia prevents
you from attaining high speeds."
KEYERS
Keyers are electronic devices controlled
by paddles similar to those on a "bug" for automatically making dits and
dahs, and often incorporate other useful operating features, including
buffers and memories. Many include "iambic" type of operation by
a "squeezing" motion which provides for alternate dits and dahs, which
further automates sending and in this way reduces total effort. An
iambic keyer will always produce perfect characters, even though they may
not be used in our code.
Katashi Nose here says "If you
have already mastered a bug, it will take about three weeks to convert
to electronic-key sending. Once you are converted, you are hooked
because now your bug fist is ruined [ed. for most people]; an entirely
different technique is required." If your keyer has
"forced character spacing" (FCS), use it! This may take several weeks practice,
but your sending will be real armchair copy. It is worth the
effort.
KEYBOARDS
Finally, the keyboard (including
the use of electronic computers with programs for using their keyboards)
automatically makes all characters from a typewriter type of keyboard.
Both keyers and keyboards often include teaching programs for learning
the code and/or improving code abilities, as well as having memories for
various purposes. This is about the ultimate in code production.
(Machine sent CW is considered almost a "must" for good copy when signals
are very faint, including QRP-- and for very high speed work (hand sending
just won't hack that.)
Keyboards also have much to offer the beginner in learning the code initially and for improving one's skills. What may be possible hand-key speeds?
Psychological testing shows the average
rates at which people can tap a fingers:-
On the High side: 9.7
per second, or 576/minute, (300 in 31 sec)
Average: 8.6 per second,
or 516/min. (300 in 35 sec.)
On the Low side: 6.7
per second, or 402/min. (300 in 45 sec.)
If we assume that a dit is one "tap"
and a dah is equal to two "taps" (two nerve pulses: one down and one up),
then we may say:
| Taps | Letters | Group Frequency | Taps x Frequency |
| 1 | E | 0.130 | 0.130 |
| 2 | T I | 0.166 | 0.332 |
| 3 | A N S | 0.214 | 0.642 |
| 4 | D H M R U | 0.192 | 0.768 |
| 5 | B F G K L V W | 0.124 | 0.620 |
| 6 | C O P X Z | 0.139 | 0.834 |
| 7 | J Q Y | 0.024 | 0.168 |
| Average per letter | 1.000 | 3.494 |
At this rate, assuming the above
rates can be maintained for periods of time needed to send messages, news,
etc., the slowest keying rate would be 23 wpm, the average 30 and the highest
33 wpm.
AN INTERESTING BUG
The Sydney Australia GPO Telegraph
Office in 1946 produced a bug that had two separate swinging arms for dots
and dashes. There were 3 knobs: one for dits, one for automatic dahs
and one for manually controlled dashes. The knobs could be positioned
at either end of the base-plate for easy use by right or left handed people.
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