EFE-40 Radio

EFE-40 Table Top 40m SSB Transceiver

- DDS tuning, very quiet receiver, designed by TA3OM in Turkey!

EFE-40 is a 40m Monoband Transceiver designed by TA3OM in Turkey.

Initially, it was the price that caught my eye, a built and tested QRP transceiver with DDS for only $120 US.

It has a very quiet NE602 receiver which is perfect for 40m. It also has DDS tuning, which eliminates drift. The DDS board and the receiver board come from TA3OM, and the cabinet I used was from https://www.circuitspecialists.com/electronic-enclosure-em-02.html

The cabinet halves are steel and the front and back are aluminum.

I ordered a 50K AF Gain POT with ON-OFF from Amazon.

The S-meter is vintage FT-101, and I have a 50K pot on the back to adjust it. I also added a very large electrolytic capacitor across the terminals to slow and smooth the action.

I also put a push-on switch on the rear panel to replace main tuning knob "push and turn" operation.

The wires for everything except the antenna screw into terminals on the main board. The DDS board has a soldered power connection and a "press on" 3 conductor plug.

The one thing I had to work on was the tuning encoder, which was not getting clean pulses to the microprocessor, there were lots of errors.

I ordered a new, larger encoder from Mouser and added a couple .1 mfd capacitors across the outputs to get a good reliable tune.

The supplied encoder has detents and no real friction, I was happy to replace it with a more VFO-like tuning mechanism. Also, the supplied encoder is mounted on the DDS board, I liked being able to mount the new encoder directly to the front panel.

A JA ham beat me to EFE-40 and inspired me to match his flair and style. His Youtube video is here:

https://www.youtube.com/watch?v=u5z5C7HCwUg

I will have my own video on Youtube shortly!

de Wb8yqj Don...

 

Make a Free Website with Yola.