I've heard much talk about "Software Defined Radios" or SDR as they are usually referred to. I wanted to get my feet wet, but I didn't want to get
soaked with buying a $2500 Flex Radio. A friend (K2TL) was telling me about an SDR radio he built and the results of it and I was impressed. What impressed me even more is that the radio only cost ten bucks. Yep, that's right, ten dollars. The radio he spoke of was designed by Tony Parks, KB9YIG and made available at what must be approximately cost from his web site. The web site is:
www.kb9yig.com and the model is SoftRock Lite II.
Before I begin telling you how wonderful the radio is, let me tell you some of the drawbacks. The model I purchased only works on 40m (other models are available) and then only a portion of that band. Specifically, it will tune a segment below and above 7056 khz. How big of a segment is up to the quality of the soundcard in your computer. Most computers will allow you to tune from 7032 khz to 7080 khz; a total of 48 khz. Higher quality soundcards that plug into your USB port allow it a 96 khz or even a 192 khz bandwidth, centered around 7056 khz. Another detractor about this radio is you must use it with a computer. It will not operate as a stand-alone radio, it plugs into a soundcard and then a program acts upon it to make it produce audio. The final bad point is that it comes as a kit.
So that's the bad news, now let me tell you the good news. As far as needing a computer... virtually every Ham owns one or more computers. About the kit building... it's a small kit, both in quantity and size. Only a handful of components are needed to construct this simple radio and only two coils need to be wound. Half of the components are surface mounted components and the others are individual discreet components. The time to build the kit varies per kit builder but mine took me a day. I started in the morning, stopped for the usual number of phone calls, meals, etc and I had it on the air that same evening.
So how well does it work, you ask. The best I can say is -- WOW! It works as well, if not better, than my Kenwood TS-2000. With the SDR, I'm able to pick out stations that are buried in noise or QRM on my Kenwood. The software controlling the radio is called "PowerSDR." It's provided free and at least two other free software programs are on the web that can be used with SDR's. The programs allows you to demodulate all the popular modes such as CW, SSB, AM, FM and you can apply all sorts of filters to it to make sound the way you want it to sound. The bandwidth of the received signal can be squeezed all the way down to 25 hz. Someone operating just a couple of hertz away will not be heard.
The best I can tell you is to listen and try it for yourself. You don't have to buy or build anything to try this as you need only to download the program and an audio file from the Flex Radio web site.
73,
Frank Wroblewski
W2XYZ
Great results. Mike, KC2Q
