Homebrew FT8 | Q R P e r

Many thanks to Cao (BG6LH) who writes:

Hi, Thomas!

I would like to share my QRP FT8 kit for Field Operation.

A long time ago, I was seeking the most lightweight QRP kits for FT8 field operation. My goal was to have just one radio, one antenna, one phone, without too many cables, boxes, etc.

Finally, I designed a PCB. It is a Bluetooth DIGI Adapter and can be mounted on the rear panel of my FT-818.

Just plug it to the DATA and ACC jacks. It can be powered by ACC jack’s 13.8V Pin.

It works well with FT8CN, an android FT8 app.

Now, my dream has come true!

My Antenna was a so-called GAWANT, designed by JF1QHZ, I guess it’s a simple Vertical EFHW. I built it with a 1.2 meter rod.

It’s working on 7~28MHz bands, not very efficient, but so small and portable.

For FT8 QRP POTA, field operation, all of these components can be put in a small bag, and deployed in minutes.

I shared my PCB design on Github. If anyone wants to modify it, you are welcome to do so!

https://github.com/BG6LH/FT-81x-BT-DIGI-Adaptor

Thank you for sharing this, Cao. This is absolutely amazing and an incredibly clever design! I suspect a lot of FT-818/817 enthusiasts will make this same build via your design!

Thank you for reaching out and for sharing your work with the QRP community!

Many thanks to Pete (WB9FLW) who writes:

Adam Rong BD6CR has designed a simple DSB Transceiver for FT8. Crystals are available for 7.074 MHz. and 14.070 MHz (which can be “pulled” with a trimmer to 14.074 MHz).

Using only 4 Transistors, 2 IC’s, 3 Toroids, 5 Diodes/LED’s and a handful of resistors and capacitors this one watt wonder will get you on the air in no time.

One could build this on Perfboard (see above), or use Ugly/Manhattan style construction. There are no plans for a circuit board.

Adam posted this on groups.io crkit:

“I built this 7074 DSB 1-watt radio and made 6 FT8 QSO with JA stations in 15 mins last weekend. It is fun to operate by switching PTT manually to keep it simple and lower current consumption.”