Monday, July 16, 2012

The SDR Chronicles (#5: Conclusions)


After five weeks of daily use, my conclusion is that the Excalibur Pro, and down-converting SDRs in general, are useful for Utility DXing.


As noted early on, this radio is less like something you listen to, and more like something you use like a tool.  You wield it.  It's not for beginners, unless you want a learning curve.  It's best to learn the radio jargon and the basic DXing mind set the usual ways, thus becoming ready to unleash the power of the Excalibur Pro.

Hams will prefer the Flex, which also has a 100-watt transmitter.  They might also like any of quite a few smaller, cheaper boxes intended for experimenters.  Hams and DXers also have a viable alternative in the Perseus, another experimenter's favorite, though I'm glad my agonizing decision process led to the WiNRADiO.

WiNRADiO provides a programming language, Radio Basic. This will be worth exploring at some point. It is like the old BASIC that most people my age learned to program with, minus the line numbers.  I hated line numbers anyway.  They made it much slower to edit your code.  FORTRAN, a compiled language with a roughly similar syntax, got along for generations just fine without them.

Here are my gripes about the Excalibur Pro:

Gripe #1: The AGC seems dodgy.  The overshoot on CW can get pretty annoying.  Maybe it needs more fiddling with the parameters. These are, thank goodness, mostly brought out to the user, though I give the caution that the wrong settings can turn a basically good radio into a barely listenable radio in seconds.  While I don't expect any digital substitute to sound like a good analog loop such as on my Drake R-4, it would be nice for it to sound like my DSP-based NRD-545.

Gripe #2: While the keyboard shortcuts are user-definable and helpful, it would be nice to have something like Photoshop, where the user can create combinations that do whole new actions not on the default list.

Gripe #3: There aren't enough hours in a day to have fun with the thing.

Here are my likes about the Excalibur Pro:

Like #1: The waterfalls, though not as configurable as I would like, are very good for playing Whack-A-Mole, quickly logging signals on different frequencies when the going gets heavy.  Right before the last CME, during a red-hot 11 meter opening, I logged 54 different Spanish language "freeband" frequencies in under an hour.  One quickly gets used to what different modes look like, spending less time searching through other noises for the pay dirt.  In a similar manner, I've been able to get a good handle on what the Mexican military has been up to for the years since it vanished from ALE.  You'll have to read the column for that one, though.

Like #2: The "spectrum analyzer" window at the bottom can give a very quick overview of HF's condition in a very short time.  The opening mentioned above became evident when this display suddenly lit up at the high end, which is usually just textures made by this QTH's legendary noise floor.  Again, a task that might have taken tens of minutes can be done in about that many seconds.

Like #3: This same window is perfect for finding and displaying the various "funny noises" on HF that everyone has meant to seriously investigate but never quite had the time. It's easy to get a sense of what's really going on in such swept-carrier oddities as The Squiggle, The Frog, and chirp sounders. The latter can be used to get a sense of propagation by where the diagonal lines disappear.  None of this has generated any answers yet, but it helps one ask the right questions.

Like #4: The optional frequency extension to 50 MHz has its uses, such as quickly confirming all CHP's new frequencies without having to tie up the scanner for what is basically grunt work.  It will be fun to see if the fall's low-VHF skip can be DXed in the same manner as HF.


This project was definitely worth the non-trivial financial investment required.