Posts Tagged ‘minima’

Minima Digital Board

After procrastinating for a very long time I finally summoned up the ‘whatever it was I needed to summon up’ to get a move on with the Minima transceiver. I planned on tackling the digital board first as it seemed logical. It did however need me to solder an Si570 onto the board without any solder paste. So it was going to be a bit of a struggle.

The method I chose was to put a healthy load of flux on the pads and a blob on both of the ends. Align the chip then solder one end, applying a small amount of pressure onto the chip. Then the other end, then back to the first and then to the second again. Making sure I had seated it correctly. after that the other pads seemed dead easy.

The result was that it worked (I think). Although I am unsure as to why is does stay on a single frequency. This will need a bit of looking at. Here’s a very brief video.

It’s chilly in here

I’m going to use it as an excuse but really it isn’t….The shack is cold (Its a garage really) and the thought of going in there really wasn’t that appealing. We’ve had some pretty miserable weather since the end of November and its been a full time effort just to go out and walk the dog. I’d also taken on the mechanical build of the SatNOGS project as part of the club project and that took up way more time that I thought. Now that’s finished it was time to get on with a few things of my own.

First things first, looking at the Minima digiatl board it seemed like something that could be built and tested in an afternoon. I was nearly right, in the interim I had lost / put in a safe place, the LM1117 3.3v regulator and didn’t have a spare (Like I keep spares of stuff like that, I’m not a professional you know).

Minima Digital Board

Built what I could and here is the result. Stone me it actually powered on an worked first time, but there isn’t any power to the Si570 and that’s a whole different ball of solder.

Onwards and upwards

Autumn = projects time

I usually cycle to work. Wow I hear you say, what a guy….Well thanks but I hadn’t finished the introduction. Cycling means you notice the seasons a lot more than if you drive. Its still the season for shorts and after some very mild days we’re definitely heading towards fully developed autumn. So what?

Well its time to spend fewer hours outside (because you’ll be blown across the street) and more time preparing for those murky days when projects are preferable to souwesters.

This year I have got a couple of PCB’s that need populating. 1 of them is the Budd Churchward Morseduino. The other is the Minima Transceiver.

Budd created a neat little barebones arduino and morse code decoder and he kindly gave me the gerbers. It is essentially a very simple device that will allow audio to pass through and it will give a reasonable decode of CW. I say reasonable because it is never going to be as good as your purists ears but it’ll help get the less talented on the air (hopefully). This video gives you a flavour

Project 2 it the Minima Transceiver, by Ashran Farhan of BitX fame. It is my first foray into complete rig build for the experimenter so I’m expecting some tinker time. Essentially it is a Arduino controlled simple transceiver (Any spot the link here?). This will be a lot more involved and I’m just getting my head around the schematic.

There seems to be a lot of useful information about so if I get stuck then google will no doubt be my friend! Here’s a little taster.

The Minima transceiver


This is the latest project from Ashaar Farhan. Component cost is said to be less than $100. This is based around a Si570 sythesiser and a programmed Arduino micro-controller IC. It looks a simple to duplicate rig covering up to 30MHz. It is the successor to the BITX rig I think. The IF is 20MHz. If you only want 0-15MHz or 15-30MHz (i.e. not both) the rig get even simpler.

As it stands it produces 1W pep but it is easy to add a further PA. 

Although a kit of parts is available, I am not aware of a full kit with enclosure and a PCB being available as is the case with the BitX from Hendricks Kits.

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