Tuesday, July 17, 2012

Building my first SDR (Software Defined Radio)

Wow my SDR on 40m is up and running. 

(Softrock  receiver) Where can I get a receiver kit http://www.giga.co.za
Here is the details
Here is the link to to the webSDR server http://zr6aic.giga.co.za:8901/
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I am starting to build a SoftRock Lite II SDR receiver for 40m Band and will publish my experiences with the construction and testing.
I will use my default Ubuntu sound card that could only sample 96Khz but will be looking for a internal or external sound card that would be able to sample 192khz/24 to replace the 96Khz card to give me bettor bandwidth on 40m.
Here is some pictures during the construction and testing process.

Sort all your components and measure and label them before you start assembly
Check the numbers on the Capacitors carefully

I used Solder paste to put on the surface mount components before I placed them on the board
Her is the PCB with solder paste on IC Pads
Transformer wound

Softrock lite II testing the local oscillator divider on 40m.
28,22 Mhz (40m) Mixer I and Q input signals on scope.

Testing your Local oscillator as in assembly document

Testing the Oscillator

Wounding the inductors. (Keeping track of the amount of wounding is important)

Following the test on the assembly instructions

And some more test

I am still waiting for some toroid rings to complete the Softrock kit but decided to expose my Funcube on the satellite part of the 2M band in the mean time.
I now have two softrock receivers on webSDR receiver (80,40,30,20M bands)
Here is the link http://zr6aic.giga.co.za:8901/