=  NOW 35 WPM  =  TEXT IS FROM JUNE 2020 QST  PAGE 43 =

IMPEDANCE, RETURN LOSS, SMITH CHART, AND TDR TIME DOMAIN REFLECTROMETER
PLOTS.  TABLE 2 SUMMARIZES THE STICK 230S SPECIFIED PERFORMANCE AND
FEATURES.  STICK 230 TESTING  I BEGAN MY TESTS BY CHECKING THE STICK 230
OUTPUT AGAINST WWV AT 10 MHZ.  THE FREQUENCY WAS WITHIN 20 HZ OF WWV, AND I
DID NOT DETECT ANY NOTICEABLE FREQUENCY DRIFT OVER A 5 MINUTE TEST PERIOD.
I ALSO FOUND THE FUNDAMENTAL FREQUENCY OUTPUT LEVEL TO BE 8R5 DBM OVER THE
FULL FREQUENCY RANGE.  WHEN USED AS A SIGNAL SOURCE, KEEP IN MIND THAT THE
OUTPUT WAVEFORM IS ALMOST A PERFECT SQUARE WAVE, AS YOU CAN SEE IN THE 50
MHZ FUNDAMENTAL SPECTRUM OUTPUT OF FIGURE 4.  THIS RELATIVE SPECTRUM IS
CONSTANT OVER THE FULL FREQUENCY RANGE OF THE INSTRUMENT.  THE ODD HARMONIC
AMPLITUDES ALMOST EXACTLY FOLLOW A 2/N, THE EQUATION FOR THE AMPLITUDE OF
ODD HARMONICS OF A PERFECT SQUARE WAVE.  NEXT, I RECORDED THE OPEN CIRCUIT
OUTPUT IMPEDANCE AS MEASURED BY THE STICK 230.  THIS GIVES AN INDICATION OF
THE IMPEDANCE MAGNITUDE YOU CAN ACCURATELY MEASURE AS A FUNCTION OF
FREQUENCY.  THE RESULTS, TABULATED IN TABLE 3, INDICATE THAT ACCURACY WILL
DROP OFF AS YOU GO HIGHER IN FREQUENCY, ESPECIALLY FOR HIGHER IMPEDANCE
LOADS.  FOR THE ALL IMPORTANT SWR TESTING, I CHECKED THE STICK 230 AGAINST
A PRECISION 50 LOAD, AND THEN SHORTED MICROWAVE ATTENUATORS OF 5 DB 1R92 1
SWR, 3 DB 3R01 1 SWR, 2 DB 4R42 1 SWR, AND 1 DB 8R7 1 SWR.  BECAUSE THE
=  END OF 35 WPM TEXT  =  QST DE W1AW  <