DX University – Visalia 2015 DX University Visalia California – 2015

DX University – Visalia 201DX University – Visalia 2015 Digital Communications Methods for the DXpedition Side Ed Muns W0YK

DX University – Visalia 2015 Ed Muns W0YK Ed’s primary interest in amateur radio is CW contesting and DXing. In 2004 he entered his first RTTY contest and has enjoyed the RTTY mode. It has helped him improve his operating skills across all modes. He is the contest director for the CQ RTTY contests (WW and WPX), the NCJ NA RTTY Sprint and co-sponsors the 10-Meter RTTY Contest with AA5AU. Ed also authors the RTTY Contesting column in the NCJ. After 32 years with Hewlett-Packard Company as an engineer and executive, he now farms wine grapes on 13 of his 77 acres in the Santa Cruz Mountains. Muns Vineyard designated wine is found on several well known labels as well as on his own brand--Muns Vineyard.

DX University – Visalia 2015 Ed Muns W0YK Operating here as P49X, Ed is also licensed as 7J1ACJ and has operated as YK0A, 6Y4A and HC8N.

DX University – Visalia 2015 Digital Approach for the DXpedition Just like CW and SSB … Make a serious effort, or don’t do it – DXpedition resources are precious Prepare, prepare, prepare – Equipment, software – Skilled operators Don’t relegate digital to an afterthought!

DX University – Visalia 2015 Digital Goals for the DXpedition Same goals as CW/SSB for uniques, ATNOs, bands, etc. 10% of total QSOs QSO rates of Set relative goals between modes Hold the digital mode to the same standards as CW & SSB!

DX University – Visalia 2015 Digital Modes used by DXpeditions RTTY – Baud – 170 Hz shift PSK31 rarely JT65 very rarely Others almost never

DX University – Visalia 2015 Why RTTY? Historically embedded in our equipment, software and familiarity The greatest common denominator Not necessarily the “best” technical digital choice today. Clearly, the social reality. RTTY reaches the largest audience

DX University – Visalia 2015 Meeting the Goals Superlative decoding – top-of-the-line pileup receiver – MMTTY, 2Tone and DXP38 decoders – 4-6 decoders, including one on the TX frequency – configured and optimized for state-of-the-art pileup decoding Experienced RTTY pileup ops – not just “RTTY experience” – experienced contesters are a good start, but they need to skill at working huge pileups in split mode

DX University – Visalia 2015 Critical Components K3, or equivalent – Sub-RX – 500 Hz 8-pole roofing filter – RX antenna option for low-band RX antennas – P3 very useful microKEYER II, or equivalent WriteLog or N1MM Logger – multiple decoders – call sign stacking

DX University – Visalia 2015 Configuration Highlights 500 Hz DSP IF bandwidth – narrow to 250 Hz occasionally to test effectiveness – DO NOT use Dual Tone Filter MMTTY for main RX/TX modem – 2Tone Normal, 2Tone Flutter and DXP38 parallel decode – turn off AFC and NET – MMTTY on Sub-RX to monitor TX frequency; AFC on FSK transmit if K3; AFSK otherwise

DX University – Visalia 2015 Operate Split UP 2; keep spread as small as possible – beware of “edge creep” Work one frequency until impossible to copy, then move slightly Be patient Try to stack multiple calls, but don’t wait too long – TU, NW 599 – Always work in order received

DX University – Visalia 2015 Reward the Behavior You Want Short calls Well-timed calls; good tailenders Stay on a frequency as long as you have acceptable behavior and rate Don’t reward bad behavior – calling out of turn; long calls; poor tailending – QSY if behavior is slowing you down

DX University – Visalia 2015 Messages DX has nominally only 3 messages: – CQ P49X P49X CQ – W0YK 599 – TU P49X UP DXers: – should send call only 2-3 times, then listen – report: 599 W0YK

DX University – Visalia 2015 What the DXpedition Should Expect of Us Listen, and then listen some more! Short messages Split proficiency Call when it is quiet Practice in contests Police

DX University – Visalia 2015 Listen, Listen, Listen Same as CW and SSB Optimize your decoding Dual-receive highly recommended – requires 2 RTTY decoders Figure out the pattern by listening!

DX University – Visalia 2015 RTTY Messages Short: – TU, optionally – your call (no DE) 1-2 times after CQ, then listen 0-1 time only in report – 599 once – nothing else, unless the DX operator asks for it Modular: – short message elements – chain together

DX University – Visalia 2015 Split Operation Build skill Always double-check settings Requires: – sub-receiver + 2 RTTY decoders – or, agile operation of A/B VFOs

DX University – Visalia 2015 Other Tips RTTY has more “quiet times” in which to drop your call Contest activity for practice Don’t police or talk to policemen – maybe a well-timed ‘UP 2’

DX University – Visalia 2015 What is RTTY? A pair of redundant reciprocal CW signals – Mark and Space, 170Hz apart – Baudot code, rather than Morse 60 WPM (45.45 Baud) Requires SW (or, HW) decoder/encoder – UI is text keyboard/display

DX University – Visalia 2015 What is RTTY? … receiving Local “tones” are like CW pitch – default 2295/2125 – your choice; lower is less fatiguing – independent of RF transmission

DX University – Visalia 2015 What is RTTY? … transmitting Two (religious) choices: FSK (Frequency Shift Keying) – just like CW AFSK (Audio FSK) – Local tones into SSB mic input – offset dial frequency suppressed carrier +/- local tone

DX University – Visalia 2015 How? RTTY decoder for receive – software, e.g., MMTTY (free), 2Tone (free) – hardware, e.g, PK232, Hal DXP38 RTTY encoder for transmit – often bundled with decoder and called a MODEM (modulator-demodulator), or TNC (Terminal Node Controller) Standalone or integrated into logging SW Interface between radio and decoder/encoder (PC)

DX University – Visalia 2015 How? … commercial or homebrew interface Receive (decoder) is typically a standard audio cable Transmit (encoder) – FSK: CW-like keying interface – AFSK: standard audio cable

DX University – Visalia 2015 Resources Website: reflector: Dayton CTU RTTY presentations NCJ RTTY Contesting column

DX University – Visalia 2015 Happy RTTY DXing!