R:030303/1836Z @:NN0MDH #:1200
R:030303/1818Z @:NN0MDQ #:867
R:030303/1821Z @:NN0MDC #:299
RR NOALL
DE NNN0ASA 043
R 031800Z MAR 03
FM CHNAVMARCORMARS WILLIAMSBURG VA
TO ALNAVMARCORMARS
INFO ZEN/HQ USASC FT HUACHUCA AZ//AFSC-OPE-MA//
ZEN/HQ AFCA SCOTT AFB IL//GCGS/MARS//
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UNCLAS
SUBJ: CHNAVMARCORMARS BCST 03-03 - SOUND CARD MODES
A. NTP 8(C) CHAPTER 9
1. REF A DOES NOT ADDRESS OPERATIONS WITH THE NEW SOUND CARD MODES.
OUR CURRENT CONVENTION OF SHIFTING FREQUENCIES TO CENTER THE
INTELLIGENCE IN THE SSB BANDWIDTH NEEDS TO BE RE-EXAMINED. HERE IS A
QUICK SUMMARY:
   A. MT-63 - SINCE THIS MODE HAS THREE POSSIBLE BANDWIDTHS (500 HZ,
1000 HZ AND 2000 HZ) SHIFTING FROM ONE MODE TO THE OTHER WOULD
REQUIRE SHIFTING FREQUENCIES WITH EACH CHANGE. AMATEUR PROGRAMS HAVE
DECIDED ON A DEFAULT WHERE THE LOWER EDGE OF THE BAND IS PLACED AT
500 HZ SO THE UPPER END OF THE PASS BAND WOULD BE AT 1000 HZ, 1500 HZ
OR 2500 HZ FOR THE THREE BANDWIDTHS.
   B. PSK-31 - MOST AMATEUR PROGRAMS USE A DEFAULT OF 1000 HZ IN THE
SSB SPECTRUM. SINCE THIS IS A VERY NARROW BANDWIDTH MODE, MANY
CHANNELS CAN FIT INTO AN SSB SPECTRUM, ESPECIALLY USEFUL FOR ECOM.
   C. Q15X25 - THIS IS A NEW 15-TONE HF AX25 PACKET MODE OPERATING
WITH AN 1800 HZ BANDWIDTH CENTERED BY DEFAULT AT 1375 HZ IN THE SSB
BAND.
   D. HELLSCHREIBER, MFSK16, MFSK8, THROB, FAX, SSTV AND OTHERS USE
DIFFERENT BAND CENTERS WITHIN THE SSB SPECTRUM.
2. THE FOLLOWING SOUND CARD MODE STANDARDS WITHIN NAVMARCORMARS ARE
EFFECTIVE IMMEDIATELY:
   A. ALL SOUND CARD MODES - RADIOS WILL BE OPERATED IN UPPER
SIDEBAND MODE.
   B. MT-63 - THE LOWER EDGE OF THE 500 HZ, 1000 HZ OR 2000 HZ DATA
ENVELOPE WILL BE PLACED AT 500 HZ ABOVE THE USB SUPPRESSED CARRIER.
   C. PSK-31 - THE CENTER OF INTELLIGENCE WILL INITIALLY BE CENTERED
AT 1000 HZ ABOVE THE SUPPRESSED USB CARRIER. ESTABLISHING ADDITIONAL
CONVERSATIONS ABOVE OR BELOW THIS INITIAL FREQUENCY IS AUTHORIZED AS
LONG AS THE 3 KHZ BANDWIDTH IS NOT VIOLATED.
   D. Q15X25 - THE CENTER OF INTELLIGENCE WILL BE SET AT 1375 HZ
ABOVE THE SUPPRESSED USB CARRIER.
   E. OTHER SOUND CARD MODES - USE THE DEFAULT CENTER FREQUENCY OF
THE SOFTWARE YOU ARE USING. IF STATIONS ARE USING DIFFERENT PROGRAMS,
THEY NEED TO CONFIRM THEY ARE USING THE SAME DATA FREQUENCY.
3. COMMENTS OR PROBLEMS ENCOUNTERED WITH THESE STANDARDS SHOULD BE
FORWARDED TO THIS OFFICE VIA THE CHAIN OF COMMAND. AFTER A PERIOD OF
OPERATIONS AND AFTER ALL PROBLEMS HAVE BEEN RESOLVED, THE CHANGE WILL
BE MADE A PERMANENT PART OF NTP 8(C).
4. NAVMARCORMARS: PROUDLY SERVING THOSE WHO SERVE.
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