! COPYRIGHT (c) 2000, 2009 - Thomas B. Perera: 4-21-2009 full-auto roto-bug 10-01-2006 added rotobug 02-14-2006 >
Visit his website for much more information:
Richard's keys are shown below
and these are his introductory remarks:
When I returned to active ham radio in the fall of 1998, after a silence of
25 years, I found myself looking for a good straight key and a set of
paddles. Being especially interested in the homebrew aspects of our hobby, I
decided to work out some new designs that, to my knowledge, had not yet been
tried. I started out by making large keys and paddles, but having been bitten
by the QRP bug, I decided to develop a series of small and portable
Since I am not a machinist, I wanted to come up with designs that would
work well even when built by an amateur metalworker (like myself). After
trying a couple of other approaches, I arrived at what I call the
The lever force is provided by a compression spring that pushes the lever against a fixed plate. The lever pivots with respect to the fixed support on two precision balls that fit into milled pockets at each side of the lever. The balls can be of brass, nylon, teflon, delrin, etc. The ball pivot holds the lever in alignment while it moves, and the lever force is provided by a compression (or tension) spring. The spring force also holds the pieces together when the lever is at rest. In my experience so far, the ball pivot provides adequate stability and a crisp and smoother ''feel''. This basic mechanism can be used either in straight keys or single and double paddles. Some of my recent designs use miniature ball bearings rather than the ball pivot, and some use magnetic repulsion instead of springs. All of the key designs shown here have been used successfully on the air. None of the designs have been optimized for high speed keying because I am still in the 15-18 wpm range. As I get faster, so will the paddles.
Click on photographs then click "GO BACK" to return to text.
10 Ball-Pivot Straight Key:(24KB)
This is the first ball-pivot design. It uses 1/4-inch steel balls and has some ''drag'' in its ''feel''. It is made mostly of aluminum, and mounted on a cocobolo wood base. The knob is made of the same wood.
20 Miniature ball-pivot Straight Key:(20KB)
This is the first QRP-sized straight key to use the ball-pivot mechanism. It uses Teflon pivot balls, and force is provided by a compression spring. Contact spacing is set by the small wheel at the front of the key. Although there is no locking mechanism, the adjustment does not shift significantly during operation. The key uses brass contacts. It feels quite nice and I use it often.
30 Miniature ball-pivot Straight Key:(20KB)
This is the second ball-pivot miniature straight key but it uses a tension spring to provide the restoring force. The tension is set by pulling out the spring tension adjustment to the desired degree and then locking it with the thumbscrew near the top of the unit. It is also provided with a locking mechanism so that it will hold its adjustment. The pivot balls are of Delrin plastic. This straight key was used to help work out the basic design prior to using it in a paddle. All aluminum. Very crisp ''feel''.
50 ''Fancy'' Brass Straight Key:(28KB)
This is my first attempt at a ''fancy'' brass straight key. It is very heavy, made of solid brass and mounted on a bocate wood base. It has a ball- bearing movement, and travel and force adjustments share the same vertical shaft. All of the parts of the key are mounted on a brass baseplate which is then mounted on the wooden base.
60 ''Fancy'' Brass Straight Key:(32KB)
This is my second attempt at a fancy straight key. Solid brass construction, with bubinga wood base and knob. The lever is pivoted on conventional ball bearings mounted in the bearing supports. Side-play is kept to a minimum by careful machining and assembly. Contacts are also made of brass and the lever rest position, contact spacing, and lever force are all separately adjustable and lockable. Very good ''feel''. I use this key daily.
70 The Prototype Ball-Bearing Straight Key:(24KB)
This is my first straight key. It is a ball-bearing design, made entirely of aluminum. The upper screws set the limits of travel, while the wheel below the lever sets the force. The unit has a good ''feel''.
80 Miniature Ball-Bearing Magnetic Repulsion Straight Key:(22KB)
This miniature straight key is of conventional design with ball bearing pivots. The return force is provided by a pair of rare-earth magnets working in the repulsion mode. Operating force is adjusted by sliding the lower magnet away from the common axis. The knurled knob in the cneter is for locking the magnet slide in place, and key travel is set by the knob in front. The key is machined from aluminum allow, with stainless steel and brass fittings. While small in size, the key is very solid and feels like a much larger unit. It is my best effort at a QRP straight key.
90 Miniature QRP Straight Key:(16KB)
This is the first attempt at a small ''QRP'' key using a non-conventional pivot mechanism. Instead of pivot points or bearings, the key lever is connected to the base through a piece of very thin shim stock. This connection does not contribute to the operating force but it eliminates lost motion and side play. The force is provided by a compression spring compressed by the large knob on top, and the wheel below the red knob is used to adjust the travel distance. The ''feel'' of the key is somewhat different from a conventional key, but it has been used on the air with good success. The shim stock connection has shown no sign of fatigue and it is easily replaceable. All aluminum construction, nice ''feel''.
100 Non-Iambic Rocker-Plate Paddle:(27KB)
This is my first attempt. It uses a rocker-plate mechanism. There is some lost motion, and the ''feel'' is not crisp. Construction is all aluminum, with some plated brass fittings.
110 Non-Iambic Rocker-Plate Paddle:(22KB)
This is my second attempt. The movement uses a shim-stock hinge and a lateral rocker-plate approach. It works well, but the ''feel'' is not yet there.
120 Non-Iambic Ball-Pivot Paddle:(22KB)
This is the first of several small paddles to use the ball-pivot design and it is the only non-iambic one. It uses a transverse ''rocker'' mechanism. The paddle lever forms a t-type arrangement with a four-ball pivot unit at right angles to it, so that moving the lever results in a rocking motion of the pivot unit. (this was worked out in an earlier and larger version, without the ball pivots.) A single tension spring at the center of the pivot unit provides the restoring force. This design solves a difficult problem in non- iambic paddle design - it is not easy to get a definite-feeling center position that is bounce-free and positive. Two finger pieces are provided to give the unit a better ''feel''. This design is further elaborated in later attempts. It works adequately but the movement lacks vertical stability. It has rather nice ''feel''.
150d Design Drawing of this key:(29KB)
160 Ball-Pivot Iambic Paddle:(27KB)
This all aluminum iambic paddle set (with ball-pivot mechanism) uses separate tension springs to set the paddle force for ''dit'' and ''dah''. Tension is adjusted by pulling out the spring-holding cylinder to the desired degree, and locking it with the thumbscrew. Paddle travel is set for each side with thumbscrews near the paddles. The two arm-stabilizers prevent rough handling from dislodging the mechanism. This unit uses lubricated brass pivot balls which are held captive by the top and bottom plates. Even though the unit is made of aluminum, it is sufficiently heavy to be used without chasing it all over the desk, especially when it is used with the stabilizer arms, which are pivoted so that all four feet may be planted firmly. A nice-working unit with a good, crisp ''feel''.
160d Design Drawing of this key:(25KB)
170 Small Ball-Pivot Iambic Paddle:(28KB)
Small ball-pivot iambic paddle which uses 3/16-inch Delrin balls. Finger piece position is adjustable. Mounted on cocobolo wood base with fingerpieces of same. This is my favorite of the ball-pivot iambics and it is also on my QSL card. Made of brass and aluminum.
180 Small Ball-Pivot Iambic Paddle:(20KB)
Very similar to above design. All aluminum, bocate wood base, purple heart fingerpieces. Stable and smooth-working.
190 Miniature Ball-Bearing Magnetic Repulsion
This is the first iambic/ball-bearing movement paddle. This miniature paddle was built to fit in a 35-mm slide box. It is a ball-bearing unit that has several interesting design features. The bearings are at the forward end of the levers and they are pre-loaded by a small compression spring that runs between them. (This also provides a DC return path for the switching action.) Such an arrangement reduces the amount of play felt in the bearings. Restoring force is provided by four rare-earth magnnets (two per side) operating in the repulsion mode. Using the magnets in this way eliminates the ''clicky'' feel that some magnetic keys have (and that some people like). Variations in force are provided by mounting the paddle magnets in a moveable carrier on each paddle so that they can be moved out of line with the stationary magnets. Distance of travel is limited by eccentric cylinderical stops beside each paddle. Fold out legs give the key stability when in use. Nice ''feel'' for such a tiny key.
200 Miniature Ball-Bearing Magnetic Repulsion
This is a refinement on number 190 above. The eccentric travel stops have been replaced with a locking screw mechanism that is easier to adjust. The fold-out legs give it a somewhat wider stance than its predecessar. Details of the magnet adjustment can be seen on the inner surface of the paddle levers. The magnets are on the between-paddle levers and on the vertical member between them. Adjusting the alignment of the magnets adjusts the force.
200b Another view of this key:(18KB)
300 This is a very unique design which used
magnetic repulsion instead of springs:(41KB)
310 This is a bug which is similar to number 300 above
but it is mounted on a wooden base:(42KB)
400 This is a right-angle bug which uses magnetic
repulsion instead of springs:(44KB)
500 The 2003 Fully Automatic Key and it's Offspring:(77KB)
This is an amazing fully automatic bug capable of making both dots AND dashes automatically. Many people have tried to design a fully automatic bug but only a few have succeeded and none have used magnetic technology. Richard Meis has done a great job of designing this bug. After 5 less successful designs, he completed this magnetic, dual lever, dual over-and-under pendulum bug. He intends to refine his design and perhaps try other automatic bugs in the future.
550 The DOUBLEBUG VIII Fully-Autmatic Key:
This is a very much improved and simplified Fully Automatic key that uses magnetic technology in a vey innovative way. You can read more about this key in Richard's website: http://bugsbylpu.googlepages.com/home2
700 The RotoBug:(123KB)
This is an amazing and complex key. It is a totally new approach to the design of a semi-automatic key that employs the rotation of a variable mass to provide the power for the string of automatic dots. The design considerations are so numerous that to fully understand its evolution and construction, you need to read Richard's descriptive paper. This paper and those for all of his other keys will be included in the next (2006) edition of Tom Perera's: Telegraph Collectors Reference CD. Ordering details are given at the top of this webpage: http://w1tp.com
705 The 2007 Fully-Automatic RotoBug:
This is certianly the most amazing and complex of Richard's keys. It is a totally new approach to the design of a fully-automatic key that employs the rotation of a variable mass to provide the power for the string of automatic dots and the rotation of another variable mass to provide the power for a string of dashes.
The design considerations are so numerous that to fully understand its evolution and construction, you will need to read Richard's descriptive paper which he will make available when it is completed.
rm_706r1 Another view of the Fully-Automatic Roto-Bug:
rm_713r1 A view of the internal construction of the Fully-Automatic Roto-