The Pico Keyer-Plus: An Iambic Keyer

Making the choice

My old oscillator made from the ‘standard’ 555 circuit has served me well with a straight key but stepping up to a paddle I needed a good iambic keyer circuit.

A PIC controlled keyer was the obvious choice and as I like soldering, it was either a kit or homebrew. There are many PIC circuits available for homebrew but I wanted something quick (don’t we all?) so I decided on the kit route.

The choice available is surprisingly large and a quick internet search will reveal many one chip kits with specifications to ponder and admire.

I decided on the N0XAS PicoKeyer-plus from HamGadgets. The main reason was because it was totally self-contained on a small PCB, this backed by good reviews and even more importantly being in my price range ($24 shipped to the UK).

As a far too brief summary, the PicoKeyer-plus kit has its own speaker; on board battery (optional external supply); most of the functions high-end keyers offer and can be used with a paddle, bug or straight key.

Well the order was placed, confirmation e-mails of packing and posting received on the same day (I was impressed) and 7 days later a sturdy little box arrived from over the pond.

Figure 1 – The contents are well packed

Construction

I’m not a great one for reading instructions but I have learnt the hard way and even with such a low component count, I knew I had to take my time and read.

They are very good quality B&W prints (PDF copy downloadable) and cover an outline of the functions followed by: beginners tips; step-by-step tick-box assembly guide; troubleshooting guide (read first to learn from others!); operating instructions; setup commands; schematic and a template for drilling the case panels.

With the soldering iron warming, up it was time to check out the components. As you can see the board is very high quality. Plated through holes and silk-screened to perfection, I hoped my soldering would do it justice.

Figure 2 - The high quality PCB

Working though the tick-box instructions was a breeze. I opted for the onboard cell so R3 and the Zener D1 are put aside for my component box.

There is no skimping with this kit, all components and hardware are good quality.

After 20 minutes all components were mounted and Dale’s instructions were telling me “we’re almost there”.

With the PIC IC carefully inserted followed by the battery a very welcome ‘73’ came from the tiny speaker.

Figure 3 – Completed with reassuring text!

Operation

My paddle was connected up and the keyer did its job at a volume I was more than happy with.

The menu functions are available from the single switch. Keeping it pressed down scrolls through a sequence of Morse characters. Releasing the switch on the character you need accesses that choice and the paddles can be used to make the desired setting.

Delving into the menu options reveals lots of functions I should think a keen contester would be proud off:

4 x 60 character memories with special keys to repeat words or join messages and save valuable memory; QSO number increments/reset/cut numbers/leading zeros; Control of Speed; tuning mode; auto letter spacing;, weight; beacon delay; Sidetone; Iambic modes (A, B and Ultimatic); paddle selection; audio tone and Tx delay compensation. All on one 8 pin PIC – amazing!

Speed control is interesting with the ability to set your speed for when the speed pot is fully counter-clockwise. You can still set the speed to whatever you want (5-62 wpm) but crank the pot fully counter-clockwise and your on the default.

Setting the messages is best achieved by slowing your sending speed as per the instructions. Learning the shortcut switches is well worthwhile so you can repeat any text such as CQ or your callsign and if you want to, you can leave a pause so you could add your RST into the pre-defined message.

It needs a case!

If you want to put the Picokeyer in an existing Homebrew rig then at approximately 2” x 1 ¼ “ x 7/8” it should fit almost anything and with on-board jumpers the job is even easier. I looked for a transparent case to show off the PCB design but couldn’t find one the right size. Instead it’s been mounted in a shortened extruded Aluminium case (Maplin N78AL) remembering to insulate it from the case first! If I can’t see the classy inside I might as well give it a good overcoat!

I had to place a piece of tape over the speaker to improve the volume and drill a small hole to let the sidetone out. The volume is more than adequate and the tone more mellow now.

Figure 4 - Fitting to the case

Conclusion

This is an excellent kit for the absolute beginner that should offer years of CW contacts.

With everything included and no wiring to off-board components it really is a great design. The quality of the service, components and instructions are very good. Dale at HamGadgets says he is looking to make the instructions even better, I’m not sure how, but I like the commitment to continuously improve an already good product.

Menus are easy to learn but I’ve laminated the key functions so I can have them to hand in the shack. Now the keyer is hooked up to the DM780 CW decoder supplied with HamRadioDelux and I am practicing for all I’m worth to get my letter spacing correct before going on air for those winter QSOs.

Figure 5 - The finished article - note the hole to let the sidetone out!

73’s Martyn