Straight Key vs Paddle vs Bug: Which Morse Code Key Should You Use?

A Morse code key is the switch an operator uses to send Morse: it turns a transmitter, or a practice oscillator, on and off. There are three main types. A straight key is a single lever you press for every dit and dah, so your hand times everything. A bug is a mechanical semi-automatic key that makes strings of dits for you while you form the dahs. A paddle drives an electronic keyer, which produces perfectly timed dits and dahs from light side-to-side touches.

No key is best for everyone. A paddle with a keyer makes clean code at speed with the least effort, a straight key is the simplest tool and makes timing visible, and a bug is a specialist’s mechanical key that rewards practice.

Morse key types at a glance

Whichever key you use, the goal is the standard proportions: a dah three dits long, one unit inside a character, three between characters and seven between words, as set out in the timing rules.

Straight key: every element by hand

The straight key is the original telegraph key: a lever on a pivot, a spring holding it up, and a pair of contacts that close when you press the knob down. Key down, the transmitter sends; key up, it stops. Nothing is automatic.

That makes the straight key completely honest. You decide the length of every dit, every dah and every space. If your dahs are too short or your letter gaps too tight, the listener hears it.

The fist

Because the timing comes from the operator’s hand, each straight-key operator develops a recognisable style known as their fist. A slight personal swing is part of the charm of hand-sent CW, but a heavy accent (clipped dits, overlong dahs, uneven spacing) makes copy hard. The aim while learning is the opposite of individuality: sending that sounds as close to machine timing as you can make it.

Technique basics

• Motion: a relaxed up-and-down movement from the wrist and forearm, with light pressure on the knob. Squeezing the knob or tensing the arm makes timing worse and tires you sooner.
• Adjustment: contact gap and spring tension change the feel. Settings are personal, and small changes make a noticeable difference, so adjust one thing at a time.
• Mounting: a straight key needs to stay put. A heavy base or a firm fixing to the desk stops it creeping as you send.

Try manual timing

A straight key’s whole job is to turn the length of your press into dits and dahs. The pad below works the same way: hold it for each element, and it decodes your rhythm and reports how long each press lasted in units, so you can see whether your dah really is three times your dit.

Try sending -.-. --.- and then .--. .- .-. .. .... Watch the unit counts: short dahs and uneven gaps are the usual things to fix.

Strengths and limits

A straight key is simple, needs no electronics beyond the radio, and works with any radio’s straight-key input. It makes the on-off nature of CW obvious, which is exactly why some teachers start students on one.

Its limit is speed and fatigue. Every element costs one full press, and figures, which are five elements each, cost five. William Pierpont’s The Art and Skill of Radio-Telegraphy estimated from finger-tapping rates that manual keying of every element tops out somewhere around 23 to 33 wpm, and many operators find a straight key tiring well before that. Long hours of up-and-down keying were associated with what telegraphers called glass arm, and later key designs moved to a side-to-side motion partly for that reason. If keying causes discomfort, stop and take proper advice; a different key or a lighter touch is no substitute for that.

Sideswiper (cootie): manual keying turned sideways

A sideswiper, also called a cootie or double-speed key, is a manual key laid on its side. A single lever rests in the middle and closes the same circuit whether you push it left or right. Most users alternate sides for successive elements, so a letter like -.- might be dah to the left, dit to the right, dah to the left.

Nothing is automatic: you still time every element and every space. What changes is the motion, which is side to side and shared between thumb and finger. It is a niche choice today, but it is a real alternative for anyone who wants fully manual keying without the up-and-down stroke.

Bug: a mechanical key that makes the dits

A bug is a semi-automatic mechanical key. It has a horizontal lever with a paddle at one end and a flexible, weighted arm at the other.

• Dits: on a standard right-handed bug, pushing the paddle to the right with the thumb sets the spring-mounted arm vibrating. A contact on the arm touches a fixed contact on each swing, so the key sends a string of evenly spaced dits for as long as you hold it over.
• Dahs: pushing the other way, with the side of the index finger, closes a separate contact for as long as you hold it. Every dah is timed by hand.
• Speed: a movable weight on the vibrating arm sets the dit rate. Sliding it further from the pivot slows the swing; moving it closer speeds it up.

So a bug splits the work. The machine makes dits at a steady rate, and the operator makes dahs and all the spacing. To send ....., you hold the thumb over long enough for exactly five dits and release; to send ...., exactly four. Letting one extra dit slip through turns H into 5, a typical bug error.

What makes a bug hard

A bug has to be matched to the operator. The dahs you form by hand must stay three times the length of the machine’s dits, and your spaces must stay in proportion as well. A common fault is dits set too fast for the hand-made dahs, which gives choppy, tiring code.

Bugs are also built for speed rather than slow sending. An adjustment article by Brian Murphy, VE2AGO, originally published in QST and hosted by Vibroplex, aims for a slowest dit setting of about 20 to 25 wpm and notes that many operators end up with poor dits below 25 wpm. Adjustment (arm stops, contact spacing, damping, spring tension) is part of owning one, and the traditional courtesy is never to readjust another operator’s bug.

A short history of the bug

Semi-automatic keys arrived in the early 1900s so professional telegraphers could send faster with less strain. The best-known design came from Horace G. Martin, a New York telegrapher. According to a history published by the Antique Wireless Association, Martin first sold an electromagnet-driven semi-automatic key, the Autoplex, patented a fully mechanical design in August 1904, and brought the Vibroplex to market in 1905. William Coffe’s all-mechanical Mecograph was filed for patent slightly earlier, so Martin was not alone. Even so, the Vibroplex became so widespread that its design is what most people picture when they hear the word bug, and the company still exists.

Paddles and electronic keyers

A paddle is only a pair of switch contacts, one for each direction. The timing comes from an electronic keyer: a small circuit, a standalone box, or a function built into many modern transceivers.

• Touch the dit side (usually the thumb side for right-handers) and the keyer sends one dit; hold it and it sends a string of perfectly spaced dits.
• Touch the dah side and it sends dahs, each exactly three dits long.
• Speed is a knob or menu setting, and the ratio of element to space stays correct at every speed.

The operator’s job becomes choosing when elements start and stop, and leaving correct gaps between letters and words. The keyer cannot fix those gaps, which is why keyer sending can still sound rushed or run letters together.

Single-lever and dual-lever paddles

Both kinds are in wide use. Some very fast operators prefer single-lever paddles because a single lever cannot produce an accidental squeeze, while dual-lever paddles are common among operators at moderate speeds.

Iambic (squeeze) keying

“Iambic” describes the keyer, not the paddle. An iambic keyer responds to both contacts being closed at once by sending alternating dits and dahs, starting with whichever side closed first. That only works with a dual-lever paddle, because only a dual lever lets you squeeze.

Take the letter C, -.-., which is dah-di-dah-dit. Without squeezing you press dah, dit, dah, dit as four separate movements. With an iambic keyer you close the dah lever, then squeeze the dit lever in as well, and the keyer alternates dah, dit, dah, dit while you hold both. Letters with alternating patterns benefit most: C, F, K, L, Q, R and Y, in an analysis by Chuck Adams, K7QO, cited in an article hosted by CWops.

The saving is real but modest, and squeezing has to be learned precisely: the faster you send, the narrower the moment in which a squeeze must land. Plenty of skilled operators squeeze only a few characters, or none at all.

Iambic mode A vs mode B

Most iambic keyers offer two modes that behave identically until you release a squeeze:

Because the two modes need slightly different release timing, an operator trained on one often sends extra or missing elements on the other until they adjust. Some keyers add further options, such as Ultimatic, in which the last paddle pressed takes priority during a squeeze.

Who makes each element? Manual vs assisted keying

Notice the last column. Every hand-operated key, even a paddle with the best keyer, leaves letter and word spacing to the operator. Run-together letters are a common sending fault on every key type, and only a keyboard removes the problem entirely.

Speed, effort and fatigue

The number of hand movements differs sharply between key types. In K7QO’s count of the strokes needed to send all 26 letters and the figures 0 to 9 once, as reported in Marshall Emm’s article “Iambic Keying: Debunking the Myth”:

The big savings come from moving to a bug and then to a keyer. Iambic keying saves much less, and less still in ordinary text, because the letters that gain most from squeezing are not among the most frequent.

Fewer strokes mostly means less effort, which matters over a long contest or a long evening of conversation. Speed is a separate question: a straight key suits slow and moderate speeds, a bug suits moderate to high speeds, and a paddle and keyer cover the whole range because speed is a setting rather than a hand limit.

Whatever the key, a relaxed hand, a firm mounting and a comfortable height matter more than the hardware. Traditional terms like glass arm are a reminder that repetitive motion over long sessions has a cost; take breaks, and seek proper advice for any persistent pain.

Which key should a beginner use?

Respected training organisations genuinely disagree here, and both approaches produce good operators.

The case for starting on a straight key

The Long Island CW Club, which runs online Morse classes, recommends that beginners start with a straight key, while welcoming students who use a bug, sideswiper or keyer, and suggests progressing to an electronic keyer as skills develop. Its reasoning is that a straight key’s on-off action mirrors the on-off pulses of Morse itself, with no extra layer of technique in between.

Other arguments for a straight key:

• You feel and hear exactly what good timing requires, which helps when you later judge other operators’ sending.
• The equipment is simple, and any radio set for a straight key accepts it.

The case for starting on a paddle

The CW Academy run by CWops takes the opposite line: its courses require a paddle (single or dual lever) and a keyer or a radio with a built-in keyer, and straight keys, bugs and cooties are not allowed in class.

Other arguments for a paddle:

• The keyer guarantees correct dits and dahs, so a beginner’s mistakes are limited to spacing and character choice.
• Speed can rise without changing equipment or technique.
• It is less tiring, which makes daily practice easier to sustain.

How to decide

1. If you are joining a class, use what the class requires. It avoids learning two techniques at once.
2. If your transceiver has a built-in keyer, a paddle costs you nothing extra in electronics; a straight key needs no keyer at all. Either way, check the radio’s key jack setting.
3. If you mainly want relaxed conversations at moderate speed, a straight key is a perfectly good long-term key.
4. If you expect to chase contests or higher speeds, plan to spend most of your time on a paddle, whatever you start with.
5. Leave the bug for later. It combines a machine rhythm with hand timing, needs careful adjustment, and is awkward at slow speeds.

Whichever you choose, learn to receive by sound first and in parallel. Sending is much easier once you know exactly what a character should sound like, which is why a sound-first plan such as the Koch method helps with the key as well as with copying. For what CW is and how a contact runs on the air, see our guide to CW in ham radio.

Common sending mistakes on any key

• Sending faster than you can copy. Operating guides advise calling at the speed you want to be answered at, so never send faster than you can comfortably receive.
• Running letters together. Keyers time elements, not gaps. Consciously leave a full three-unit gap between letters and seven between words, especially on a paddle at speed.
• Dahs that shrink on a straight key. Count a steady rhythm for the first weeks; a dah should feel noticeably long.
• Changing modes and settings constantly. Iambic mode, weighting and speed all change the feel. Settle on one set-up long enough to build habits.
• Never checking against a reference. Type a short phrase into the Morse Code Translator, play it at your target speed, then send it yourself and listen for the difference. Pair that with structured Morse code practice for receiving.