Ham Radio Meets Open Source Electronics
purushottam
Minima -A general coverage transceiver
So, what's this Minima anyway?
- Superhet design. The IF is at 20 MHz.
- No RF amp before the crystal filter. As a result, receiver has very low distortion and yet, it’s strong enough to deal with the loud signals in today’s band conditions.
- Easy to use. A single knob tunes the entire HF band. Sideband selection is automatic.
- One Button. The single F-button that toggles the RIT and swaps the two VFOs.
- 1 watt output. Add your own power amplifier to take it to your prefered power level.
- No tune up. Just set the BFO frequencies, notch the low pass filters and you’re done.
- Easy to build. The component count is not much greater than that of the BITX.
- Arduino based. The transceiver is controlled with the simple, universally available microcontroller.
- Hackable. It is easy to reprogram the Minima, change the circuit and try out new things.
Engineering is all about making choices and deciding what to leave out. So, what's not included in the Minima?
- No AGC. A good AGC to match the Minima will add complexity to the transceiver. Preference was given to undistorted audio from an unencumbered signal chain.
- 1 Watt output. You’ll want to add a linear to boost the power level.
- 20 Mhz notch. The transceiver has a deep notch around 20 Mhz. So, the transceiver works everywhere in the HF bands, except at 20 Mhz.
What I really loved is the arduino factor , not many hams are familiar with using open source boards for home projects.Though some hams have started using arduino & Rasp Pi for making digital frequency display & frequency controls.
Arduino is a very popular and easy to use microcontroller system. It is based on a specially programmed ATMEGA328P chip and PC based development environment. The PC based environment allows one to program it in simple C language (instead of assembly language). It is downloaded to the chip through a serial port without requiring programmer.
The Arduino handles a number of functions:
- Controls the Si570’s frequency with the I2C interface and Wire library.
- Interfaces to the 16x2 LCD display with a 5 wire interface.
- Tuning with RIT and two VFOs.
- Automatic switching of low-pass filters, sidebands.
- Transmit/Receive switching.
- CW keying.
The Arduino's code are called 'sketches'. The Minima sketch is available for download from https://github.com/afarhan/radiono
Read More http://www.phonestack.com/farhan/minima.html
http://yo4hhp.wordpress.com/2014/01/19/minima-transceiver/
the website claims it cost less than $100 , but I found out the rates -cabinet will not exceed Rs 2k
https://www.youtube.com/watch?v=-cRXQiNgH8w
Views appreciated !!! Hams ,SWL ,listeners, XYL , YL , OM any one :P