I have worked in an industry where we have been developing “digital radios” for many years. Many of the technologies that are finding their way into the great new fad we all call SDR (Software Defined Radios), are not new. What is new is the hardware that makes it feasible to produce small, lower-power, affordable (well, sort of..) consumer and Ham-grade equipment. Also the software that provides the signal processing power has matured greatly in recent years. Modern signal processor chips and FPGAs can support incredibly high-speed processing and interfaces. I knew one of the Engineers that claims some credit as the “founder of SDR.” Some controversy there, but this technology has been evolving for well over 20 years, and is finally hitting the main stream in Ham Radio.
The most basic (over-simplified) description of an SDR, is a radio where all of the functions are implemented in software. Of course you still need an antenna, an RF front-end with some signal conditioning or filtering, and an Analog-to-Digital converter. Theoretically from the A/D to your ears, everything can be done in software. There are many good sources of SDR information on the Web. One good presentation (although about 3 years old) can be found here. Some claim that SDR implies all control and interaction is via computer, but that is not really connected to the SDR nature of the Radio itself.
Flex Radio is the company that has brought SDR to Ham Radio in a major way. While I have been interested in their products, their price tag and the replacement of a Radio front-panel with a computer-based GUI, have kept me from jumping in. I have been wondering when some of the Ham manufacturers would finally merge the look-and-feel of a well-designed Radio panel with the great signal processing capability of an SDR platform. I had a chance to try a Beta-version of the Flex Maestro panel at the great Contest Station at NR4M in Virginia. It was not quite ready for contesting prime-time yet, but the presentation was very impressive. It had a great display and felt a bit more like a traditional Radio to me.
I have nothing against using a computer to control a Radio. But for me, a “good” radio needs to have a front panel that is attractive and enjoyable to use. Younger Hams may never want to see a physical radio panel at all, and may love the all-computer interface nature of something like the Flex Radio products. During contests, I give my computer (and N1MM+ Logger software) full control of the radio. But when not in a contest, or if I am operating portable or mobile, I want a radio that can stand alone.
There is a great deal of enthusiasm being generated by the Icom IC-7300 one of the first Radios Icom has produced that is based upon SDR technology. With this radio and the IC-7610, Icom has started to merge the look-and-feel of their radio panel (which I really like) with an underlying SDR direct-conversion signal processing platform. The IC-7610 takes SDR to another level, but with a much bigger price-tag. I have an IC-7600 which I like very much, but I am just not ready to take the price hit for a 7610. Reviews of the IC-7300 have been extremely good. I try not to be a slave to pure Tech Specs, but the IC-7300 data on the trusted Sherwood Engineering Site makes it hard not to look seriously at this radio, especially for its price.
Looking at many great reviews got my interest in the IC-7300. I have had an IC-7000 in place for Mobile use for a number of years, and it is starting to show its age. I just have not been happy with any of the potential replacements for the IC-7000 that I have seen from Icom or the other major Ham manufacturers. There was a big sale on the IC-7300 this month, and I finally decided it is time to try an SDR. With my luck in timing, this probably means there will be a new version introduced any day. I should get to start looking at it over the next few weeks, and will let you know what I find. The big question – is Icom the one to finally get it right, with their approach of merging SDR into their radio product line? I am expecting great things…..
What do you think?