Bugs - Want some Technology with That?
Marshall G. Emm N1FN/VK5FN
|A friend recently asked
about the differences between the current GHD bugs and the older, discontinued
models. The only significant difference is that the newer bugs are
covertible from dual to single lever operation, while the older ones are
one or the other. But the conversation evolved into a discussion
of the history of bug technology, and some of it bears repeating here.
The history of bugs goes back to the end of the 19th Century, and in some ways it is ironic that two of the most significant advances in the technology had to wait for the end of the 20th Century, when users were more interested in paddles and computerized electronic keyers. Those two innovations, optical sensors in place of contacts, and convertible dual-single lever operation, were introduced by Japanese keymaker Toshihiko Ujiie, the principal of GHD Keys..
One Lever or Two?
There's no such thing as "iambic" or "squeeze keying" with a bug, so the differences between single and dual lever bugs are pretty subtle and not obvious to the majority of operators. Dual lever bugs are one of the oldest ideas in telegraphy, and convertible dual-single bugs are one of the newest.
Dual lever bugs were introduced as early as 1910, and should have represented a significant advance in the art of telegraphy because a dual lever bug can be operated at higher speeds than a single. Why? With a traditional pendulum and spring arrangement, the dot lever had to be moved a considerable distance and held, to set the pendulum going. To make a dash, the lever had to come back from "full right," through dead center, and then full left. It's true the dash contacts could be set close, and little lever movement was required to make dashes on their own. But that distance is added to the full travel on the dot side in cases where a dash follows a dot. To this day, when you hear a fast bug on the air you can detect a slight delay between dots and following dashes. It actually imposes a speed limit on single lever bugs, because you get to a point where that delay between dot and following dash is equivalent to the space between characters, and the code becomes unreadable.
The dot-to-dash gap problem is eliminated when you have separate dot and dash levers, because you can begin to make the dash stroke before the dot stroke has completed. That is, when the last dot has been made, you release the pressure on the lever but don't have to wait for it to move to and through the center position before you begin making dashes.
Dual lever bugs were very rare in the early 20th century for two reasons. First, they were relatively expensive, and few telegraphers (who did not make a lot of money) could justify the price difference.
Second, and more telling, the dual lever bugs had quite a different feel to them and telegraphers found it difficult to adapt to them. Remember, a professional telegrapher was used to working at the same speed day in and day out, and they truly became creatures of habit. As is the case with straight keys and even paddles, the physical operation of the device becomes a matter of muscle-memory and trained response. When a telegrapher was first confronted with a dual lever bug, there was a tendency to rush the dash that followed a dot (compensating for the expected delay). The usual result was that the dual lever bug just didn't "feel right," and so they never became popular.
Closer to the end of the 20th Century, almost bug users were amateur radio operators, who spend less time transmitting, often need to change speeds, and generally are a lot more flexible in their application of technology. With increasing frequency, an operator who is learning to use a bug has already mastered the paddle and keyer. A dual-lever bug will seem more familiar and be easier to adapt to than a single, and the new user has no bad habits to overcome.
The early dual lever bugs are prized by collectors and operators alike, and the convertible bugs from GHD offer yet another layer of flexibility.
There are still some OT's out there who grew up with bugs, often used them professionally with the railroads or the military, and are keeping the art and science of bug telegraphy alive. And there is a growing body of modern hams who are fascinated by the older techniques and technologies and naturally attracted to bugs.
Optical Sensors or Mechanical Contacts?
It takes a fair amount of work to set up and adjust a bug and the adjustments will depend on the speed that you are setting it up for. The goal is simple-- throw the lever over and have the pendulum make a series of perfectly timed and spaced dots. The speed is determined generally by the position of the weight on the reed-- the closer to the pivot, the faster the oscillations and the faster the dots. But there's a lot more to it. To get the dots to come out right, you might need to make changes to four or five adjusting screws. If you are interested in the details, see "How to Adjust Morse Keys, Paddles, and Bugs" , but for now suffice it to say that the process is tricky and time-consuming.
In the heyday of manual telegraphy, a telegrapher might spend an entire shift doing nothing but sending code, at a constant speed, and often to the same individual at the other end. Thus a bug could be set up once, and its adjustment might not need to be changed for weeks or months, and then only for cleaning and maintenance. A typical amateur radio operator might spend an hour or two a week transmitting, and often will need to send at different speeds, or even change speeds during the course of a QSO. To some small extent the sending speed can be adjusted by changing the length of the dashes (which are made by hand), but trying to change the speed by more than a few words per minute will resulted in a distorted "weight" which can be difficult to copy.
The reason that the dots are difficult to adjust on a traditional, mechanical bug, is that the moving dot contact is on a spring attached to the pendulum. Changing the oscillation of the pendulum will change the force with which the contacts close, the distance that moving contact will travel, and the amount of time the contacts will be closed (the "dwell"). The closing of the contacts induces drag on the pendulum (the repeated "impacts" tend to slow the oscillation). The desired result is contact closings with a consistent dwell, equally spaced, for a duration of at least eight to ten dots without appreciable difference in speed from start to finish. Consistency in this area of "impact" also dictates a minimum weight or impetus for the pendulum and the force needed to set it going.
With GHD's optical sensor, there is no physical contact, no drag, and no changes in the geometry of the oscillations. A beam of light is interrupted by a flag attached to the reed; as the pendulum oscillates, the flag moves in and out of the beam, interrupting it and telling the the electronic circuitry that a dot is being "made." In orther words, there are no dot contacts, and virtually nothing to adjust when changing speed. In practice, changing the speed of a GHD optical bug is simply a matter of moving the weight along the reed. Since there is no drag, the pendulum can be much lighter, and the bug can be operated at higher speeds, with less effort.
What are You Sending With?
An old axiom of telegraphy has it that a good telegrapher can send perfect code with any sending device. Someone listening to you should not be able to tell whether you are sending with a straight key, bug, paddle and keyer, or keyboard. The goal of sending perfect code was always more difficult to achieve with a bug than with any other device, but dual levers and optical sensors have gone a long way toward eliminating the problems.
Copyright © 2003, Marshall G. Emm. All Rights Reserved