Single-lever vs dual-lever paddles: what is the difference?
A single-lever paddle has one lever that swings either way: push it with your thumb and it sends dits, push it with your finger and it sends dahs, and it can never do both at once. A dual-lever paddle has two separate levers, each with its own contact, so you can close both together. That squeeze is the whole difference: only a dual-lever paddle can do iambic keying.
Both kinds plug into a keyer, which does the timing, and in the hands of an operator who never squeezes they send exactly the same Morse.
How each one is built
Every paddle is a pair of switches with a common connection. What differs is the mechanics around them.
A single-lever paddle has one arm between two contacts. Push it one way and it closes the dit contact; push it the other way and it closes the dah contact. In the middle, nothing. Because the arm cannot be in two places at once, the keyer only ever sees dits or dahs, never both.
A dual-lever paddle, often just called an iambic paddle, has two arms side by side, each with its own spring and its own contact. For a right-handed operator the left lever, under the thumb, sends dits and the right lever, under the index finger, sends dahs (left-handers may swap them). Squeeze both and both contacts close.
Both usually connect to the keyer the same way, with a dit, a dah and a common connection. A keyer cannot tell which kind of paddle you have, except that a single-lever paddle never closes both contacts at once.
Neither is a sideswiper. A sideswiper, or cootie, also has one lever that moves both ways, but it has no keyer behind it: each side simply closes the circuit for as long as you hold it, and you time every dit and dah by hand. What is a sideswiper or cootie key? covers that very different instrument.
What the keyer does with each
With either paddle, the keyer turns a held contact into evenly timed elements at the speed you set. Hold the dit side and you get dits, one unit each with one unit of space after; hold the dah side and you get dahs, three units each. You never time an element yourself. You decide when to switch sides and when to stop, and the keyer always finishes the element it started.
A dual-lever paddle gives the keyer one more input to answer: both contacts closed. It responds by alternating dits and dahs, starting with whichever lever closed first, for as long as you squeeze. What happens when you let go depends on the keyer’s iambic mode, A or B, which Iambic keying explained: mode A vs mode B walks through letter by letter.
With a single-lever paddle that setting never comes into play. Mode A and mode B behave identically when there is no squeeze.
How the work differs, letter by letter
The clearest way to see the difference is to count the separate presses each character takes. On a single lever, every change between dit and dah is a new movement. On a dual lever, a run of alternating elements can be one squeeze.
| Character | Code | Single lever | Dual lever, squeezing |
|---|---|---|---|
| S | ... |
1 press, held | 1 press, held |
| A | .- |
2 presses | 1 squeeze |
| R | .-. |
3 presses | 1 squeeze |
| K | -.- |
3 presses | 1 squeeze |
| C | -.-. |
4 presses | 1 squeeze |
| Period | .-.-.- |
6 presses | 1 squeeze |
Letters made of one kind of element, like S, H .... or O ---, are the same on both: hold one side for the right number of elements and let go.
Fewer movements are not the same as fewer mistakes, though. On a single lever, each change is a deliberate push, and the rhythm lives in your hand. On a dual lever, the movement is shorter, but the hard part moves to the release: let go a moment too early or too late and the keyer drops or adds an element.
What each feels like
A single lever feels like rocking. Your thumb and finger rest on either side of one paddle, and you tip it back and forth. Letters with many changes, like C and the period, become quick wiggles. There is no way to squeeze by accident, so a hand that tenses up cannot produce a stray alternation.
A dual lever feels like pinching. Your thumb and finger each have a lever of their own. Letters made of alternating elements become one light pinch, released on the beat. The risk is the mirror of the single lever’s strength: a tense hand can close both levers when it meant to close one, and the keyer alternates when you wanted a plain run of dits.
The two habits do not transfer perfectly. If you squeeze on a dual lever, a single lever makes you relearn C as four movements. If you rock a single lever, a dual lever does not teach you when to release a squeeze; that takes practice of its own.
You can key a dual-lever paddle like a single lever. Just never press both at once. You lose nothing by working this way, and you can add squeezing later, letter by letter, starting with the ones where it pays off most, like C and the period.
Which should you choose?
A few plain guides:
- Not sure yet: a dual-lever paddle keeps both styles open. Key it one lever at a time and decide about squeezing later.
- You want the fewest movements: a dual lever, keyed with squeezes.
- Your squeezes keep adding stray elements: try a single lever, or key your dual lever without squeezing for a while.
- You want to time every element yourself: neither. That is a straight key or a sideswiper, with no keyer at all.
Whichever you choose, set the keyer slower than feels necessary at first. Clean elements at 15 WPM teach your hand more than ragged ones at 25.
Two keys on a keyboard are a dual-lever paddle
If you practice on a computer, you already own the dual-lever kind. Two keyboard keys are two independent switches, and you can hold both at once, which is all a squeeze is. To practice single-lever style, keep to one key at a time.
Dot & Dash works this way. Its paddles are two keys, Left Option for dits and Right Option for dahs by default; in the app’s words, “One key sends dits and the other dahs, timed for you at your speed. Hold both to alternate.” It offers iambic mode A or B, and you can choose the keys for the dit and the dah (any key but Caps Lock), so you can find out whether squeezing suits you before you buy a paddle. A keyboard does not feel like a paddle, but the timing decisions are the same.
Questions
Can a single-lever paddle send iambic Morse?
No. Its one arm can close only one contact at a time, so the keyer never sees a squeeze. It still sends perfectly timed dits and dahs; you make every change between them yourself.
Do single-lever and dual-lever paddles need different keyers?
Usually not. Both normally connect through the same dit, dah and common connections, so a keyer made for paddles works with either. A single-lever paddle just never uses the keyer’s squeeze behavior, so its iambic mode setting makes no difference.
Is a single-lever paddle the same as a sideswiper?
No. Both have one lever that moves both ways, but a single-lever paddle feeds a keyer that times every element, while a sideswiper has no keyer and you time every dit and dah yourself.