UMPP Morse keys by Peter, GM0EUL


I set out to develop a miniature paddle that was at least as good as my beloved Palm Pico Paddle, sadly Palm Radio closed down and these are no longer available but will forever remain the iconic paddle for the ultra-lightweight portable operator.

So the bar is very high and with this first release version of the UMPP (Ultra-Miniature Precision Paddle) I believe I have achieved it.

Best in class principles

I looked at the attributes of some of the acknowledged best keys in the world including my own Begali Expedition (S/N 499) . Begali and other top end manufacturers use precision bearings to support the arms and magnets instead of springs for a deliciously smooth action. So does the UMPP-1

And not all miniature bearings are the same. To enable precision adjustment of the gap, a consistent action and minimal variation between units and batches you need tight tolerances. I use Japanese EZO bearings which are smooth running, noise and vibration tested and Abec rating 3-5/tolerance P6-P5. Cheap bearings bought online can be far too wobbly (Abec 1/Tolerance P0) for precision equipment.

Each one built with love

I want you to love your UMPP-1 and I put a lot of care into building each one by hand.

The main components are 3-D printed from PFA, a plant based plastic-like material that is much less harmful to the environment than conventional plastics.

The printed components are finished by hand to give them a smooth and tactile feel. The bearings and magnets are held in place with epoxy resin and the contact points are adjustable by means of stainless steel grub screws. Pure copper foil is used for the contacts and the key is wired for a standard 3.5 mm jack plug.

To see the keys in action please have a look at some of the videos below!

I've developed a way of refurbishing Palm Mini Paddles by converting the original 3-pin connector to a standard 3.5mm (1/8") jack socket that will take a standard slim 3.5mm plug. This video shows how its done. I can also replace the original 3-pin connector with a like-for-like Molex socket if you prefer that. Please get in touch for more details or to book your paddle a new socket.

A brief explanation about how the arms are articulated in a UMPP paddle and how this affects the keying action and feel. Also at the end I show you how to clean your paddle if necessary to get it performing like new again.

A UMPP-1 in its natural habitat! Thanks to Mike AC0PR for this great video of his SOTA activation of Granite Mountain W7U/WS-025. What a beautiful location. Nice sending and the QCX-mini is a great little radio too.

Every UMPP paddle gets puts through its paces to make sure its up to scratch before it goes out to its new owner. This key happened to be ready just as a CWops CWT was starting so I gave it a go. These are a few of the contest Qs, speed 26-28 wpm out, up to mid-30s in by the sound of it. The tiny paddle is well up to the speed and precision needed for contest operating! Its off to its new owner in Oregon now. BTW- you'll hear a couple of American and Canadian stations coming back to me in the video- not bad for 5 watts from Scotland into a home-brew hexbeam on a 25ft pole. Love qrp cw!

I was asked yesterday whether a UMPP-Academy could be set very light (10g) and with a gap of about 0.5 thou. It managed the tension fine and I got the gap working well at 1.2 thou, which is no perceptible movement. Here's a video of the experiments.

This is an early prototype. Version 3 was pretty good really. Versions 1 and 2 were a bit wobbly because they used much lower spec bearings and I soon realised there are several different grades of bearings with increasingly tight tolerances as the price goes up. The bearings in the current production versions are very good.

The beta release version. A few people have these and several of them are still in use. I myself still use a beta key but I've added the cover to make it easier to hold. All current keys are fully enclosed.

Thanks to Nigel G4BSW for posting this great video of his UMPP-Academy in use with his KX-2.

The KX-2/3 bracket is now available as an option with the Academy paddle.