=  NOW 40 WPM  =  

SUPPLY.  NEXT TO IT IS A USB TYPE B SOCKET FOR CONNECTION TO A PC.
FINALLY, TO ITS RIGHT IS THE UNITS ON/OFF SWITCH SEE FIGURE 5.  ON
THE RIGHT SIDE ARE FOUR BNC CONNECTORS LABELED TTLIN, EXTIN, CH1,
AND CH2.  THE LAST TWO HAVE LEDS TO INDICATE WHICH CHANNEL IS ACTIVE
IT MAY INDICATE THAT BOTH ARE ACTIVE.  UNFORTUNATELY, THE LETTERING
FOR THESE FOUR CONNECTORS MAY BE DIFFICULT TO SEE UNDER POOR
LIGHTING CONDITIONS.  THE MINI CD HAS ALL THE BUTTONS ON THE FRONT
PANEL SHOWN THE RECEIVER IS AN SDR THAT USES AN INTERMEDIATE
FREQUENCY FOR THE FINAL EXTRACTION OF THE TONES FIRST IN DIGITAL
FORM, THEN FED AS AUDIO TO A BUILT IN SOUND CARD, AND FINALLY SENT
VIA USB TO A COMPUTER.  ANECDOTALLY, THE RECEIVER PASSBAND IS NEARLY
DEVOID OF NOISE.  IN VERY UNSCIENTIFIC TERMS, THE RADIO DOESNT SEEM
TO HEAR MUCH OF ANYTHING ASIDE FROM THE INTENDED SIGNALS.  THIS MAY,
IN PART, HAVE TO DO WITH PORTABLE OPERATIONS, BUT EVEN STILL I FIND
THAT, COMPARED TO OTHER QRP FT4/ FT8 SETUPS I HAVE USED, THE SIGNAL
TO NOISE RATIO APPEARS TO BE MUCH BETTER WITH THE QDX.  COMPARED TO
OTHER QRP SETUPS, MY EXPERIENCE IS THAT THE QDX HEARS WELL ENOUGH
THAT THERE IS BIGGER SPREAD IN SNR READINGS, AND BECAUSE THE QDX
HEARS SO WELL, A REPLY WITH THE OTHER STATION BEING UNABLE TO HEAR
IT SEEMS TO BE MORE FREQUENT THAN WITH OTHER RADIOS I HAVE USED.
THE QDX DOES AN EXCELLENT JOB OF LEVERAGING THE MODES AVAILABLE IN
WSJT X AND SEVERAL OTHER POPULAR MODES.  CONCLUSION OVERALL, THE QDX
IS AN EXCELLENT TRANSCEIVER.  IT IS COMPACT, EASY TO USE, AND NEARLY
FOOLPROOF.  I HIGHLY RECOMMEND PURCHASING THE CASE UNLESS YOU ARE
HIGHLY SKILLED AT FABRICATING YOUR OWN ENCLOSURES, OR IF YOU HAVE A
3D PRINTER, AS SOME TEMPLATES ARE AVAILABLE ONLINE.  THE RADIO IS A
WORTHWHILE ADDITION TO MY GO BOX FOR PORTABLE OPERATIONS, BUT IT
WOULD FUNCTION EQUALLY WELL AS A DEDICATED RADIO IN THE SHACK.
SIGNAL GENERATORS REVIEWED BY PAUL DANZER, N1II N1II ARRL. NET  YOU
CAN NO LONGER BUY A SIGNAL GENERATOR LIKE YOU USED TO.  ALTHOUGH
SOME MANUFACTURERS DIVIDE THEIR PRODUCTS INTO TWO CLASSES ANALOG
SIGNAL GENERATORS WHOSE PRIMARY OUTPUT IS CW SINE WAVE, AND VECTOR
OR DIGITAL SIGNAL GENERATORS WHOSE PRIMARY OUTPUT IS COMPLEX DIGITAL
WAVEFORMS MOST ANALOG SIGNAL GENERATORS CAN GENERATE SQUARE,
TRIANGULAR, AND VARIOUS DIGITAL WAVEFORMS.  MOST DIGITAL SIGNAL
GENERATORS ALSO CAN GENERATE CW.  THE OLDER GENERATION GENERATORS
WERE CAPABLE OF CW ONLY OUTPUT.  DRIFTING DUE TO HEAT VACUUM TUBES
WERE VERY GOOD AT MAKING HEAT AND DRIFT IN CALIBRATION WERE MAJOR
PROBLEMS, AS WAS THE AGING OF COMPONENTS WITH TIME.  THESE PROBLEMS
DROVE THE SIZE AND MECHANICAL DESIGN, AS WELL AS THE TYPE OF
OSCILLATOR USED IN THE UNIT.  IN TURN, THESE CONSIDERATIONS RESULTED
IN LIMITS TO THE FREQUENCY RANGE AVAILABLE WITH MULTIPLE RANGE
SWITCH POSITIONS.  NEARLY ALL SUCH UNITS HAD ONLY ONE OUTPUT CHANNEL
AND HAD TO BE RECALIBRATED PERIODICALLY.  FOR HIGH ACCURACY
FREQUENCY GENERATION, MANY LAB APPLICATIONS REQUIRED A STAND ALONE
FREQUENCY COUNTER, WHICH HAD ITS OWN
=  END OF 40 WPM TEXT  =  QST DE W1AW  <