Sunday, April 19, 2009

Rock n' Roll

I finished the softrock V9.0 today My version is complete with a band switched bandpass filter and covers 160M through 10M. I plugged in the firebox (presonus sound card) I am using as my A/D converter, the USB plug and 12V (it will run on anything above about 7.5V) and my vertical and fired it up. After I installed the USB driver, the radio came right online. I was using Rocky by VE3NEA as my software. This is the first time I've had a radio to use with R0cky so its a new experience, so I had to play with the configuration a little to get the right combination. One thing I forgot was to specify an output once I did that, I was on 40 CW!!!

This system is not like PowerSDR. It is much simpler in its character. The Softrock V9.0 is not exactly contiguous tuning using Rocky. The V9.0 has a Si570 programmable oscillator and the center freq of the oscillator changes in 20khz steps

Recall that its a broad band IQ signal that is fed into the A/D converter. I am running the A/D at 48khz so when I am set to 7020 on the programmable oscilator I can tune anywhere with in that 48khz window (from 6996 to 7044). If I want to go above 7044, I jut kick the Si570 up to the next programmed center freq. Here is how the radio sounds I have the bandwidth set to about 85hz in this recording.

Recall this is a $58 dollar kit. My intention is to set this up with PowerSDR and calibrate this radio and then use the S-Meter in PowerSDR as a field strength meter using a laptop on a wifi network configured as a remote base. I'm sure it will do that in spades.

The kit went right together and fire up the first time. It was fun to build. Make sure you follow the directions. I had to rewind a transformer because I presumed both input and output transformers were identical. They are not!! I caught my mistake before I installed the transformer so it was quick work to rewind it but it would have been better if I had been paying attention.

I will write more on this little beauty as I get more into its capabilities but for now, I recommend this little project. The quality of the RX is directly linked to the quality of the A/D converter (presonus firebox in this case)