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SHORT DELAYED ECHOES CONTINUE TO AMAZE SHORT DELAYED ECHOES CONTINUE TO
AMAZE  SOME, BUT NOT ALL, TRANSMISSIONS PRODUCE ECHOES AT TWO FREQUENCIES.
GENE GRENEKER, K4MOG  ON JANUARY 7, 2013, BETWEEN 220 PM AND 300 PM EST, I
HEARD SHORT DELAYED ECHOES WHILE CALLING CQ ON 18R090 MHZ CW.  I HAVE HEARD
SHORT DELAYED ECHOES BEFORE ON 80 METERS.  MANY AMATEURS HAVE REPORTED BOTH
SHORT AND LONG DELAYED ECHOES, AND A BODY OF LITERATURE DISCUSSES THE
SOURCE OF THESE EVENTS, SO THERE IS NOTHING NEW ABOUT SHORT DELAYED ECHOES,
RIGHT?  WRONG.  WHEN I HEARD THE SHORT DELAYED ECHOES, I STARTED KEYING
SPECIFIC PATTERNS OF MORSE CODE DITS TO EXCITE THE ECHOES FOR RECORDING AND
LATER ANALYSIS.  EACH TIME I SENT A DIT, I COULD HEAR A 675 HZ SHORT
DELAYED RETURN ECHO MY RECEIVE FREQUENCY WAS OFFSET 675 HZ HIGHER THAN MY
TRANSMIT FREQUENCY.  NOW FOR THE INTERESTING PART FOLLOWING EVERY FOURTH
DIT IN THE SEQUENCE, I NOTICED TWO ECHOES ONE AT 675 HZ AND THE SECOND AT
APPROXIMATELY 1420 HZ, SLIGHTLY MORE THAN TWICE THE FIRST ECHO FREQUENCY.
I SENT DITS AT HALF SECOND INTERVALS, THEN AT OTHER TIMINGS OVER THE NEXT
40 MINUTES.  MY ANALYSIS OF THE RECORDED DATA PRODUCED RESULTS THAT I
COULDNT EXPLAIN.  MEASURED ECHOES FIGURE 1 SHOWS A SIGNAL EVENT TIMELINE.
FROM LEFT TO RIGHT, RECEIVER NOISE IS EVIDENT BETWEEN STARTING TIME 0 TO
APPROXIMATELY 60 MS.  AT ABOUT 60 MS I KEYED THE TRANSCEIVER WITH A DIT
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