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"DEAF" PACKET



LADS & LASSIES

MY RECENT EXPERIENCE STIRRING UP THE ANTHILL FROM PIKE'S PEAK ON 28.400 146.52 AND 446.00 GAVE ME A SMALL PEEK AT THE  AMOUNT OF QRM AND HETERODYNE THE SPACE STATION IS HEARING, REMEMBER THIS IS ONLY 14,100 FEET, A WEEKDAY AT ABOUT 13:00-15:00 LOCAL TIME.
PACKET IS MUCH PICKIER IN WHAT IT DECODES, SO IN ADDITION TO A 6dB CAPTURE RATIO TO CLIMB OVER THE TOP OF OTHERS, MOST PACKET NEEDS AT LEAST A 12dB SIGNAL TO NOISE RATIO (JUST GUESSING) FOR THE TONES TO BE CONSIDERED UNCORRUPTED.
THAT'S A TOTAL OF 18 dB.
DO THE MATH FROM A 5W STATION +37dBm ON A VIRGIN PASS WITH NO ONE ON THE UPLINK +18dB  = +55dBm OR AROUND 300 WATTS OR SO. TO "CLIMB OVER" THE QRM AND BE DECODED.
MOST PEOPLE ARE RUNNING 5-50 WATTS ON THE UPLINK, THIS IS ONLY 8dB FROM ONE LEVEL TO THE OTHER.
I'D GUESS FOR MOST OF A US OR HIGH-DENSITY HAM COUNTRY PASS IT DOESN'T GET OVER THE HETERODYNE STAGE.
YOU CAN SEE "FUZZED" OR CORRUPTED PACKETS BEING REPEATED OCCASIONALLY HERE IN CHICAGO.

ANY BELIEVERS?

DE MATT
MATTHEW E. SQUIRE  WB9YLP, T2
SR. R&D TECHNICIAN
LINDGREN RF ENCLOSURES
400 HIGH GROVE BLVD.
GLENDALE HEIGHTS, IL. 60139
	USA
TEL. 630.307.7200 X 1055  FAX 307-7571
MESQUIRE@LINDGRENRF.COM

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