1Watter & 5 Watter Keyer Circuit by W8DIZ

After I posted my request for a favorite electronic keyer circuit on qrptech@groups.io, my friend Bill K6WHP reminded me that the 1 Watter & 5 Watter transceivers used a nice keyer circuit.

Diz W8DIZ designed his keyer circuit around the ATTINY45 microcontroller.

I robbed the keyer chip from my 1 Watter 30M Transceiver for this experiment. I decided to build this circuit using the manhattan construction style technique. 

I took my time and built this circuit over several evenings spending 15 or 20 minutes per session. A college professor once told my class that "Sometimes the journey is more important than the destination." It is fun to build and learn new things and to stop and think along the way.

The keyer works great and I like the iambic B mode the best. I used my favorite LM386 circuit for my amplifier, but I plan on building a discrete amplifier for it just to be different and to learn something new. If you have any favorite discrete amplifier circuits please let me know!

In conclusion, I need to connect the keyer to one of my transceivers and make sure that it will key the transmitter. Give this keyer circuit a try and let me know what you think.

73 for now...

N8WQ

PMK Keyer from Midnight Design Solutions

 

This is my build of the PMK Keyer.

On July 7th of this year I posted on qrptech@groups.io a message that I was in the mood for building a keyer and I asked for favorite circuits from everyone. No one mentioned the PMK Keyer from Midnight Design Solutions. While I was looking up keyer circuits I found this circuit design by Dave Benson K1SWL. I already had three Picos in stock in my junk box, so I went ahead and ordered the pcb along with some prototype boards and headers for experimenting with the Raspberry Pi Pico. George Heron N2APB kindly included a BOM to order all the parts from Mouser on his web site. That saved me a lot of time! 

https://midnightdesignsolutions.com/pmk/

The hardest part of this build for me was getting the right female headers installed for the Pico on the PMK pcb. At first I used some headers from Adafruit, but they were not tall enough and the soldered male pin headers on the Pico were not going deep enough into the female headers. Luckily, I have a Hako FR-301 de-soldering gun and I was able to desolder the Adafruit female headers with no problem. Next time I will be more careful and do better planning! :)

Building the PMK keyer went smoothly and the only confusion I had was with the Setup mode and Operational mode of the keyer. I asked George some questions and he was able to give me the information I needed to understand how everything worked.

PMK discussion, news and support are available at https://groups.io/g/cwtd

This is a nice keyer and for me it was a easy build. The firmware is written in MMBasic and for me it is easier to understand than MicroPython. Using a terminal program called Tera Term to access the firmware and to Setup the keyer had a cool retro vibe!

I want to thank George and Dave for making this keyer available. Now I am motivated to see what other projects I can come up with using the Raspberry Pi Pico!

73,

Chaplain O. Alan Jones, USA Retired

N8WQ