Morse keys and paddles

Morse keys and paddles
Purpose	Sending Morse code (CW) by hand
Manual keys	Straight key; sideswiper (cootie)
Semi-automatic	Bug: mechanical, with automatic dits and manual dahs
Automatic	Paddle with an electronic keyer
Paddles and keyers
Paddle types	Single-lever and dual-lever (iambic)
Iambic keyer modes	Mode A and Mode B
Usual layout	Thumb sends dits, index finger sends dahs; reversible in the keyer
Usual connection	3.5 mm stereo plug: tip dit, ring dah, sleeve common

Morse keys and paddles are the devices hams use to send Morse code by hand. Every key is, at heart, a switch that turns the transmitter on and off, but the types differ in how much of the timing they do for the operator: none with a straight key, half with a mechanical bug, and nearly all with a paddle and an electronic keyer. Each has its devotees, and many CW operators own several.

Straight keys

The straight key is the classic telegraph key: a lever with a knob, a spring and a pair of contacts. Press the knob and the transmitter keys; release it and it stops. The operator forms every dit and dah, so all the timing comes from the hand. Adjustments set the spring tension and the gap between the contacts. A straight key should be fastened down or sit on a heavy base, placed far enough back that the forearm rests on the desk and the wrist does most of the work.

Straight keys are easy to learn and give a recognizable, human rhythm. Most operators find them comfortable up to around 20 words per minute; beyond that they become tiring, and professional telegraphers who sent all day once suffered from "glass arm", a painful overuse injury. Military surplus keys such as the World War II J-38 are still common. American keys traditionally have a low, flat knob, while European keys often have a taller ball-shaped knob and a heavier lever. The author Dan Romanchik, KB6NU, finds a straight key tiring after 30 to 45 minutes of sending. The ARRL holds an annual Straight Key Night on New Year's Day.

Sideswipers

A sideswiper, often nicknamed a cootie key, has a single lever that moves side to side between two contacts, either of which keys the transmitter. The operator still forms every element by hand but alternates sides, rocking the lever back and forth. The motion is less tiring than a straight key's, and the result has a distinctive swing.

Bugs

The bug is a mechanical semi-automatic key, made famous by Horace Martin's Vibroplex design from the early 1900s and still in production. Pushing the lever to the right with the thumb sets a weighted pendulum vibrating, which closes a contact repeatedly and produces a string of evenly spaced dits for as long as the lever is held. Pushing it to the left with the index finger closes a separate contact, and the operator forms each dah by hand. Sliding the weight along the pendulum sets the dit speed.

A bug takes more practice than a straight key or paddle, and a badly adjusted one sends dits too fast for its operator's dahs.

Paddles and keyers

A paddle doesn't key the transmitter directly. It drives an electronic keyer, which generates perfectly timed elements: hold one side for a stream of dits, the other for a stream of dahs. Nearly every HF transceiver has a keyer built in, and external keyers add features such as message memories for calling CQ and contest exchanges. For a right-handed operator the thumb normally sends dits and the index finger dahs, and the keyer can swap them for left-handed use.

A single-lever paddle has one lever that moves left or right. Only one side can be closed at a time, which makes it simple and forgiving, and many high-speed contest operators prefer one for that reason.
A dual-lever paddle has two independent levers. Squeezing both makes an iambic keyer send alternating dits and dahs, named for the short-long rhythm of iambic verse. A letter C (dah-dit-dah-dit) can be sent with one squeeze starting from the dah side. A dual-lever paddle can also be used without squeezing.

Iambic keyers come in two main modes, which differ in what happens when both levers are released during a squeeze. In Mode A, the keyer finishes the element it is sending and stops. In Mode B, it finishes that element and then adds one more of the opposite kind. Mode B saves a little motion but is less forgiving of timing, and operators who learned on one mode often find the other awkward. Many keyers also offer weighting, which adjusts the length of elements relative to the spaces, and memories that remember a lever pressed a moment too soon.

Touch paddles sense the operator's finger electronically and have no moving parts. Code can also be sent from a computer keyboard.

Adjusting a key

Every key and paddle has screws that set the contact gap and the spring tension, and most operators adjust them to suit their own hand. A bug has more adjustments than any other key. A common order is to remove play from the lever bearings first, then set the dah contact gap and spring, then the dit stop and the dit contact so that dits and the spaces between them come out about equal, and finally to slide the pendulum weight to the desired speed. The classic fault is dits that run faster than the operator's hand-made dahs. Contacts are best cleaned with silver polish rather than sandpaper.

KB6NU suggests trying several types of key, since the feel of a key is a personal matter.

Makers and suppliers

Keys and paddles are made by many small firms as well as a few long-established names. Vibroplex, in the United States, has made bugs since 1905 and also sells Bencher paddles and straight keys, and Begali, in Italy, makes precision paddles and keys. Other makers and dealers include:

UR5CDX, a Ukrainian maker of single- and dual-lever paddles and hand keys, including models for QRP and portable use.
Pfeiffer Keys, in Germany, which has made keys continuing the line once sold under the Scheunemann name as "Scheunemann Edition" keys.
QRPworks, which makes accessories for portable operating, among them paddle mounts and a solid-state paddle with no moving parts.

For many years Morse Express, in Aurora, Colorado, was a well-known dealer in keys, bugs, paddles, keyers, kits and books on Morse code. Its owner, Marshall Emm, N1FN, became a Silent Key in February 2020, and the business no longer appears to be in business.

Building a fist

An operator's sending style is called their fist. A good fist means correct proportions: a dah three times the length of a dit, one dit of space between elements, three between characters and seven between words. Spacing errors are the most common fault, because they turn "AN" into "P" or run words together.

Practice off the air. Most radios can turn off transmitting while leaving the sidetone on.
Send at a speed you can send cleanly. Faster isn't better if the other station can't copy it.
Record yourself and copy it back a day later, or send into a CW decoder program as a check.
Adjust the key or paddle to suit your hand, and keep a relaxed, light touch.

If a decoder program can't read your sending, a human will struggle too. Try it with the transmitter switched off and practice until the screen shows exactly what you meant to send.

External links

Setting up and using a straight key at Electronics Notes
Setting up and using a bug at Electronics Notes
Choosing a key by KB6NU