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Author Topic: minima experiments  (Read 689 times)

Offline PG4I

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  • Homebrew + QRP = Maximum Fun!
    • Technical and operational notes by PG4I
minima experiments
« 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

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....
Joop - PG4I/QRP

Offline KI6J

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Re: minima VFO experiments
« Reply #1 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.

Stu

Offline PG4I

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  • Homebrew + QRP = Maximum Fun!
    • Technical and operational notes by PG4I
Re: minima experiments
« Reply #2 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!
Joop - PG4I/QRP