QRP Club

QRP Station => Builder's Corner => Topic started by: PG4I on February 07, 2014, 16:32:21 UTC

Title: minima experiments
Post by: PG4I on February 07, 2014, 16:32:21 UTC
I was surprised when I saw the minima transceiver design at http://www.phonestack.com/farhan/minima.html (http://www.phonestack.com/farhan/minima.html)

It uses a SI570 based VFO which is controlled through an arduino board. Tuning is accomplished with a potmeter. When turned left from the central position of the potentiometer you tune down, the further you turn the faster it goes... Turning right tunes up the same way.

I wanted to try this, so I soldered the SI570 to a homemade shield. It works! First impressions are great, more comfortable then using one of those encoders....
Title: Re: minima VFO experiments
Post by: KI6J on February 07, 2014, 19:04:07 UTC
Nice work!

I thought the "shuttle tuning" described in the article was a fabulous idea, and want to try it.  I remember using a commercial rig that tuned this way, but I can't remember what it was.  The tuning knob had a spring-like response that returned it to center, and the knob resistance increased the further it was turned off center.

I find rotary encoders annoying too.

Title: Re: minima experiments
Post by: PG4I on February 08, 2014, 06:35:08 UTC
Adding a spring would be a nice idea. Let's see if I can find a potentiometer which can be mechanically modified!