CW Keys: Straight Key, Paddle or Bug? How to Choose

Every Morse operator eventually asks the same question: which key should I use? The answer depends on speed, comfort, budget and what you want from the hobby. A heavy brass straight key feels wonderful at 15 words per minute and is a poor choice for a contest at 35. A dual paddle with a keyer sends perfectly timed code with very little effort, but it never develops the swing of a hand-sent fist. A mechanical bug sits between the two and rewards patience. This guide explains the main types of CW keys, how each one works, what its strengths and weaknesses are and how to choose and adjust one for your station.

The technical descriptions follow the encyclopedia articles on the telegraph key and on Morse code, which are linked below. Anything that depends on personal taste is marked as such.

What a Key Actually Does

A telegraph key is a specialised switch. As the encyclopedia entry puts it, the operator uses it to send pulses of two different lengths, short dots (dits) and longer dashes (dahs), which encode letters and other characters. In modern radio telegraphy those pulses are unmodulated radio waves, so the key simply turns the transmitter on and off. The timing rules are fixed: a dah lasts three times as long as a dit, the space between elements equals one dit, letters are separated by three dit lengths and words by seven, according to the Morse code article. Speed is measured in words per minute using a standard word such as PARIS.

Everything else about keys is about how to produce those lengths and spaces with the least effort and the most consistency. A straight key leaves all the timing to your hand. A bug generates the dits mechanically. A keyer generates dits and dahs electronically from a paddle. That is the whole difference, and it explains the trade-offs below.

The Straight Key

The straight key is the classic: a lever with a knob on top and a contact underneath, closed by pressing down against spring tension. The entry notes that traditional American keys had short flat-topped knobs and narrow bars, while European keys had tall ball-shaped knobs and thick bars, and that the choice is mostly a matter of culture and training. Straight keys have been made in many variations for over 150 years and have an avid collector community.

The straight key is simple, reliable and cheap, which is why it is still the first key for many learners and a favourite for portable operation. It needs no keyer, no batteries and no settings. Its drawback is the up-and-down pumping needed to send a string of dits. The entry reports typical speeds from about 5 words per minute for novices up to about 30 for skilled operators, and notes that professional telegraphers in the early days developed a repetitive stress injury called glass arm. It recommends good technique and a little side play in the key to reduce the risk, or using a side-to-side key instead.

Sideswipers, or Cootie Keys

The first widely accepted alternative was the side-to-side key, called a sideswiper, sidewinder or cootie key. The arm swings left and right, with contacts on both sides, and either direction makes a dit or a dah. The side-to-side motion uses different muscles and reduces strain. It also produces a distinctive rhythm which affects an operator’s fist. Few people use one today, but it is the ancestor of nearly every modern key. If you wire the two contacts of a modern single-lever paddle together, it behaves like a sideswiper.

The Semi-Automatic Key or Bug

A bug is a mechanical key, sometimes called a Vibroplex after an early manufacturer, that uses a clockwork-style pendulum to produce the dits. Pressing the paddle to the right with the thumb kicks the pendulum, which rocks against the contact and sends a series of evenly timed dits at a speed set by the pendulum. Pressing to the left makes a continuous contact for the dahs, and the operator times the dahs by hand to match. The entry says a skilled operator can send faster than 40 words per minute with a bug, and that the mechanism reduces hand motion and keeps dits uniform.

The bug also fixed a convention that survives in every modern paddle: the thumb side produces dits for a right-handed operator. The disadvantage is that changing the speed means moving the pendulum weight and rebalancing the spring tension and contact, and learning to time the dahs takes practice. Bugs are loved by those who value the sound and feel of hand-sent code and who have time to learn them.

Electronic Keyers and Paddles

Beginning in the middle of the twentieth century, electronic keyers took over the dit and dah timing. The operator moves a paddle from side to side, and the keyer produces perfectly timed elements. The keyer may be a separate unit or, as is common now, built into the transceiver. Keyers work with two kinds of paddle.

• Single-lever paddles have one lever with a contact on each side. Pressing to one side gives dits and to the other dahs. They cannot be squeezed, and so they work with any keyer without iambic functions.
• Dual-lever paddles have two levers, one for dits and one for dahs. Squeezing both together sends alternating dits and dahs when used with a keyer that supports it, which is why they are called squeeze or iambic keys.

The entry makes a useful technical point: iambic is really a function of the keyer, not the paddle, although manufacturers often call dual paddles iambic. It also explains that most keyers include dit and dah memory, so the operator can be about one element ahead of the transmission and the keyer still outputs machine-perfect timing. Another advantage over a bug is that the speed changes with a knob or a menu setting.

Comparing the Main Types

Iambic Modes in Brief

If you choose a dual paddle, you will meet the keyer modes. In mode A, alternating elements are produced while both paddles are held, and sending stops with the last element when you release them. In mode B, which grew out of an early logic error and is the default on most keyers, one more element than you have heard is sent after release. Mode U, the Ultimatic mode, switches to the opposite element if you press the second lever before releasing the first. Squeezing saves hand movements on some characters. The entry cites the letter C, which can be sent by squeezing both paddles, but it also reports a study that concludes the timing difficulties of squeezing at high speed outweigh the benefits. See our detailed guide to iambic mode A and B for setup advice.

Fist, Rhythm and Why It Still Matters

With a straight key, sideswiper and, to an extent, a bug, every operator has an individual rhythm called a fist. The entry notes that fists were so distinctive that listeners could identify a telegrapher after a few words, and that this was used for intelligence purposes in wartime. Electronic keyers remove most of that individuality because the code is uniform and the speed is set by the receiver’s needs. Only the spacing between characters and words stays personal. For many operators this is a plus, because clean, regular code is easy to copy for everyone. For others it is a reason to keep a straight key or bug on the desk.

How to Choose

• Beginner learning at low speed. A decent straight key or a single paddle with a keyer. Learn with proper spacing from the start. Our article on learning Morse code explains how to build speed without bad habits.
• Contester or someone who wants speed. A dual paddle and a good keyer, which saves effort over long events. Practise with a simulator such as Morse Runner.
• Portable and low-power operator. A small straight key or a compact paddle, which weighs little and does not depend on a battery-hungry keyer. See our guide to QRP operating.
• Traditionalist. A bug or a sideswiper, accepting the longer learning curve.

Setting Up Any Key

1. Make it stable. A key that slides across the desk ruins your timing. Use a heavy base or non-slip feet and place it so that your forearm rests comfortably.
2. Adjust the gap and tension. Too wide a gap and heavy spring tension tire the hand, while too narrow causes double contacts. Adjust a little at a time.
3. Check the connector. Match the key’s plug to the jack on your radio or keyer and follow the manual, since the wiring differs between devices.
4. Set the keyer. Choose the speed, weighting and iambic mode, and turn on the memory if you want it.
5. For left-handed operators, swap the dit and dah sides in the keyer or reverse the wiring of the paddle, as the entry notes some do.
6. Listen to your own sidetone. Adjust the pitch and volume so you can hear spacing mistakes.

Common Problems and Simple Fixes

• Doubled or stuttering dits. The contacts may be dirty or the gap too small. Clean the contacts gently and widen the gap slightly.
• Dahs that come out as dits, or the reverse. The paddle wiring or the keyer’s paddle-reverse setting is wrong. Check the connector and the menu.
• Squeezing that never feels right. Try the other iambic mode, lower the speed for a while or switch off squeeze keying until your timing is steady.
• Sore wrist or forearm. Change the height of the key, rest the whole forearm on the desk and, with a straight key, loosen the side play as the encyclopedia entry suggests.
• Weak or uneven sidetone. Use headphones, raise the sidetone volume and keep the transmitter’s own monitor separate from the keyer’s tone.

A Simple Practice Routine

Whatever the key, ten minutes a day beats an hour on Sunday. Start by sending a few lines of plain text slowly, with careful spacing, and record yourself if your radio or computer allows it. Listen to the recording and look for characters that run together or gaps that are too long. Then send callsigns and short exchanges at the speed you will use on the air. Once the rhythm is steady, raise the speed by a few words per minute. If you use a keyer, keep the weighting at the default until you know what you are changing, and avoid sending faster than you can copy, because the other operator may reply at your speed.

The Bottom Line

There is no best key, only a best key for your goals. A straight key teaches timing and travels well, a bug rewards patience, and a paddle with a keyer gives clean code with the least effort. If you are not sure, start with a simple straight key or a single paddle, learn good spacing, and add a dual paddle later if you want to go faster. The most important point is the same for every type: good timing and a steady rhythm matter more than the hardware.

Frequently Asked Questions

What is the best key for a beginner?

Either a simple straight key or a single-lever paddle with a keyer works well. Both teach spacing. A single paddle avoids the strain of pumping a straight key at speed.

Do I need a dual paddle for iambic keying?

Yes. Squeeze keying needs two levers and a keyer that supports it. A single-lever paddle works with any keyer, but it cannot be squeezed.

What is a bug key?

A semi-automatic mechanical key that makes dits with a pendulum while the operator sends dahs by hand. It is sometimes called a Vibroplex after an early maker.

How fast can I send with a straight key?

The encyclopedia entry gives roughly 5 words per minute for novices and up to about 30 for skilled operators. Technique and key adjustment affect both comfort and speed.

What is the difference between mode A and mode B?

In mode A the keyer stops with the element in progress when you release the paddles. In mode B it sends one more element than you heard. Most keyers let you select either.

Can I use a paddle without a keyer?

No. A paddle only closes contacts. The dit and dah timing comes from an electronic keyer, which may be built into your radio.