Single-lever and ultimatic adapter

Photo @LA3ZA 

Here's an adapter that emulates both a single-lever paddle mode and the ultimatic mode. It is meant to go between a dual-lever paddle and an iambic keyer. The adapter has been implemented in an AVR Butterfly in C and it is compatible with Morse keyers such as the one in the Elecraft K3 and the K1EL WKUSB. The single-lever emulation is probably the most novel part and it is meant to make it easier to practice single-lever keying on a dual-lever paddle.

The advantage of the single-lever paddle

My single-lever PCB keyer.

It may seem like a bad idea to downgrade from a dual-lever paddle and iambic keyer to a single-lever paddle. It must be inefficient since each individual dash and dot has to be generated by a right or left movement of the paddle. Despite this, many of the champions in the High Speed Telegraphy competitions use single-lever paddles, often home-made ones. How can that be?

K7QO, Chuck Adams, wrote "Using an Iambic Paddle" and compared the dual-lever paddle with the single-lever with respect to number of movements. If all 26 letters of the English alphabet and the numbers from 0 to 9 are sent, the single-lever paddle requires 73 strokes while a dual-lever and an iambic keyer requires 65. This is 11% less.

But when N1FN, Marshall G. Emm, wrote "Iambic Keying - Debunking the Myth" he analyzed the 7 letters that are faster to send with an iambic keyer - C, F, K, L, Y, Q, and R - and found that only one of them, the L, is among the 12 most frequent ones in English reducing the gain in efficiency to only 5%. He illustrated it this way:

Guess what't wrong with this figure? He didn't see the R and forgot that it is also among the most frequent letters.

Is the ultimatic Morse keyer really that efficient?

Vintage Ten-Tec Ultramatic Keyer KR50. Nice name but the
similarity to ultimatic seems to be coincidental.

Iambic keying with a dual-lever paddle is by far the most popular form for Morse keying. But in recent years an old alternative has reemerged. This is the Ultimatic mode which goes back to W6SRY in the 1950's.

The experience seems to be that it needs less timing precision than the iambic mode for letters like A, N, R, and K (· —, — ·, · — ·, — · —). When both paddles are squeezed, the last one to be pressed takes control. So when right-left is pressed one gets a dah followed by dits, not the dah-di-dah-dit of the iambic keyer.

It is very simple to add code for an ultimatic keyer to an iambic one. In recent years this has led to an ultimatic option in some stand-alone keyers, such as: