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RTTY. Lets get started Mike, K4GMH k4gmh@arrl.net. INTRODUCTION. Where to find HF RTTY on your radio RTTY Code or what is all this noise about Interface between Computer and Radio Computer RTTY Software Sources of information RTTY Contesting. WHERE TO FIND RTTY OPERATION.
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RTTY Lets get started Mike, K4GMH k4gmh@arrl.net
INTRODUCTION • Where to find HF RTTY on your radio • RTTY Code or what is all this noise about • Interface between Computer and Radio • Computer RTTY Software • Sources of information • RTTY Contesting
WHERE TO FIND RTTY OPERATION • 10 meters: 28080-28100 KHz, during contests 28060-28150 KHz • 15 meters: 21080-21100 KHz, during contests 21060-21150 KHz • 20 meters: 14080-14100 KHz, during contests 14060-14140 KHz • 40 meters: 7025-7050 and 7080-7100 KHz, during contests 7025-7100 KHz • 80 meters: 3580-3600 KHz, during contests 3570 (or lower)-3600 KHz • 160 meters: No RTTY contesting • Notes: • Avoid PSK-31 operations near 28120, 21070, 14070, 7070, 3580 KHz • Avoid the NCDXF beacons at 21150 and 14100 KHz • For more detail, see www.aa5au.com/gettingstarted/rtty_subbands.htm
RTTY CODE • RTTY uses the 5-bit ITA2 code • 5 bits means only 32 characters can be represented • To get around this there are two “sets”, Letters and Figures • Each set uses 26 characters plus 6 common entries • Letters mode • “A” through “Z” (26 CAPITAL letters) • Ltrs shift, Figs shift, null, space, carriage return, line feed • Figures mode • “0” through “9”, various punctuation (26 characters) • Ltrs shift, Figs shift, null, space, carriage return, line feed • Letters Shift and Figures Shift latches which set displayed
MARK AND SPACE • RTTY transmission is a continuous carrier which shifts frequency between two distinct frequencies • There is no amplitude modulation, only a pure carrier similar to CW with the addition of a frequency shift. • The lower RF frequency is known as the SPACE • The upper RF frequency is known as the MARK • The difference between the two is known as the SHIFT • Using FSK for a RTTY transmission with display setting at 14090 • Mark frequency is 14090 KHz • Space frequency is 14089.830 KHz • Shift is 170 Hz • Characters sent at 45 baud or 1/6 second per character (60 WPM)
INTERFACE TYPES • The difference is the way your transmitter generates the RF signal. • AFSK = audio frequency shift keying • Mark (2.125kHz) and Space (2.295kHz) audio signals generated from computer sound card to audio input on radio. • AFSK is should be transmitted in LSB mode so Mark frequency is higher than Space frequency. • FSK = frequency shift keying • With FSK, your transmitter receives a simple on-off signal which causes the carrier frequency to shift between mark and space. • Digital signal generated from computer viaserial port or USB (through USB to converter) to FSK input on radio.
FSK vs AFSK • Why use FSK? • Ability to use your CW filters in most rigs • Easier than AFSK to set up • No need to adjust audio drive • Why use AFSK? • If your rig doesn’t have an FSK input • Same interface as PSK31 • Ability to use AFC
COMMERCIAL INTERFACES • There are many commercial interfaces with many options • Buxcomm – Rascal • Donner’s – Digital Interface • Ham Radio Solutions – EZMaster • KK7UQ – Model II • MFJ – 1273, 1275, and 1279 • MicroHAM – USB Interface II • RigExpert – Navigator • Tigertronics – Signal Link • West Mountain Radio – RigBlaster • ZLP Electronics - DigiMaster
Computer Software • Software for computer decoding received RTTY signal and • generating RTTY signal for transmission (that I am familiar • with) • - MMTTY (http://mmhamsoft.amateur-radio.ca/) • - MixW2 (http://mixw.net/) • - Ham Radio Deluxe w/ Digital Master 780 • (http://www.ham-radio-deluxe.com/) • MMTTY RTTY only, but used with all major contest • logging software. Free • MixW2 includes most digital programs including CW • (send/receive), SSB, SSTV, PSK, Packet (receive only), • Olivia, etc. $50 • HRD/DM 780 PSK, SSTV, Olivia, etc. Free?
SOURCES OF INFORMATION AA5AU Website: Getting Started on RTTY - detailed step-by-step instructions (www.aa5au.com/rtty.html) RTTY Contest Macros - examples and explanations: (www.rttycontesting.com/rttymessages.htm) RTTY Tutorials - WriteLog, MMTTY, software-generated FSK, Microham Microkeyer, etc. (www.rttycontesting.com/tutorials/tutorials.htm) Downloads - Super Check Partial (RTTY version), keyboard templates, etc. (www.rttycontesting.com/downloads/downloads.htm) Miscellaneous - SO2R, contest notes, survey results, USB-to-serial adaptors, improving your RTTY scores Getting Started on RTTY: AA5AU website (www.aa5au.com/rtty.html) British Amateur Radio Teledata Group (BARTG) (www.bartg.org.uk/articles/Getting%20started%20on%20RTTY.pdf) DX-Stations Guide to RTTY Operations (www.plicht.de/ekki/rtty/dxguide.html) Sound Card Interfacing: Understanding Soundcard Interfacing by Ernie Mills, WM2U (www.qsl.net/wm2u/interface.html) Simple Serial FSK Setup (users.skynet.be/ON4AOI/keyer.shtml) Understanding FSK and AFSK (homepage.mac.com/chen/w7ay/cocoaModem/More/Contents/part2.html) Using MMTTY with FSK (mmhamsoft.amateur-radio.ca/extfsk.htm) USB-to-Serial Port Adapters (www.rttycontesting.com/usb) N1MM Logger documentation (pages.cthome.net/n1mm/html/English/Help.htm)
SOURCES OF INFORMATION RTTY Discussion: - Email reflector (lists.contesting.com/mailman/listinfo/rtty) - Searchable archives (lists.contesting.com/archives//html/RTTY/) RTTY Background: History of RTTY (www.rtty.com) Other: Article about RTTY Contesting and SO2R (contestclubfinland.com/pileup/pu4_06.pdf) – 3.8 MB file
RTTY CONTESTS • First weekend in January ARRL RTTY Roundup • Second weekend in February CQ World Wide RTTY Contest • Fourth weekend in February North American QSO Party • Third weekend in March BARTG Spring RTTY Contest • First weekend in April EA RTTY Contest • Second weekend in May A. Volta RTTY DX Contest • Third weekend in July North American QSO Party • Third weekend in August SARTG RTTY Contest • Last weekend in September CQ WW RTTY DX Contest • Second weekend in October BARTG RTTY Sprint • Third weekend in October JARTS World Wide RTTY Contest • Second weekend in November Worked All Europe DX Contest • Third weekend in December OK DX RTTY Contest
RTTY CONTESTING REFERENCES • ARRL HF Digital Handbook www.arrl.org/catalog • WriteLog for Windows http://www.writelog.com • N1MM Logger http://www.n1mm.com/ • CocoaModem (MacOS) http://homepage.mac.com/chen/ • w7ay/Site/indes.html • MMTTY http://mmhamsoft.amateur-radio.ca/mmtty • AA5AU RTTY Contesting http://www.rttycontesting.com