Digital VHF Weak Signal Modes Gary Sutcliffe W

Digital VHF Weak Signal Modes Gary Sutcliffe, W 9 XT Ken Boston, W 9 GA

Esoteric “Space” VHF Propagation Modes Want to make distant contacts beyond “normal range” Aurora - bounce off northern lights 6 & 2 M, mostly CW, “Donald Duck” on SSB Meteor scatter – bounce off ionized meteor trails Mostly 6 & 2 M, SSB, WJST Popular during meteor showers Moon bounce (EME) – use moon as a reflector 6 M & up, CW, SSB, WJST 2 M most popular band

WSJT – Weak Signal Joe Taylor Written by K 1 JT – Joe Taylor 3 Modes JT 6 M – Scatter on 6 M FSK 441 – Meteor scatter JT 65 – Moon Bounce Each mode optimized for that type of operation JT 6 M – weak signals from scatter FSK 441 – short bursts, Doppler shift JT-65 – Very weak signals, slow fading, slow Doppler shift

What do you need? Stuff you have VHF Transceiver – must have SSB mode Antenna PC Stuff you need to get PC/Rig interface (inexpensive – build or buy) WSJT program – Free download!

Sound Card Interface Unified Microsystems SCI-6 Sound Card Interface Schematic

WSJT Software Free down load http: //physics. princeton. edu/pulsar/K 1 JT/wsjt. html Standardized QSO formats – not a rag chew mode Step by step defined sequences 30 or 60 second transmit/receive periods Requires synchronized PC clocks

WJST User Interface

WSJT QSO Sequence Stations alternate 30 or 60 sec. transmissions: Station 1 Transmission CQ W 9 XT EN 53 Station 2 Transmission W 9 XT W 1 XYZ GRID W 1 XZY W 9 XT RPT RRR 73

Meteor Scatter Meteor burst Several milliseconds to maybe 30 seconds, short ones much more common Longer on 6 M, short on 2 M, very short 222 MHz Maybe 1 burst per minute visible during a good shower Maximum range out to about 1200 -1400 miles. Station Requirements 50 -100 W good, more is better Medium sized antenna best High gain antennas too narrow – don’t know exactly were meteor will appear

FSK 441 – Meteor Scatter

Moon Bounce Signal path Round trip to moon and back ~2. 4 seconds. 250 d. B loss Station Requirements 100 W single long Yagi minimum – work a few really big stations 350 W, 4 Yagis with elevation – can work equivalent stations Need to track moon Az-El

JT 65 – Moon bounce

W 5 UN

W 9 XT “QRP” EME Station Equipment: Yaesu FT-847 All mode transceiver Mirage B 2518 G 150 W 2 M amp Cushcraft 13 B 2 13 element Yagis (2) CATV 75Ω hardline Dell PC running XP Unified Microsystems SCI-6 PC I/F Plans for 2012: • Increase to 4 Yagis • KW amp

W 9 GA EME Station Equipment: 144 system: Kenwood TS-711 2 M All mode transceiver Henry 2002 2 M 700 W amp 2 X 9 el M 2 Yagis, hand aimed (not shown) M 2 preamp Laptop PC 50 MHz system: Yaesu FT 1000 MP mk. V w/FTV 1000 H. B. KW amp with a pair of 3 CX 800 s 2 X 6 M 5 X vertically pol, with elevation PC with WSJT

50 MHz EME antenna

QSLs received

Scatter Modes Lots of propagation modes F 2 – Regular HF propagation mode if high solar levels Es - Common in spring months JT 6 M lets you make contacts when there is not enough signal to make CW & SSB QSOs

JT 6 M – Scatter modes (6 M)

Ping Jockey

WSJT Resources WSJT Download: www. physics. princeton. edu/pulsar/K 1 JT/ N 0 UK Ping Jockey page: http: //www. pingjockey. net/cgi-bin/pingtalk Unified Microsystems: www. unifiedmicro. com Inexpensive PC sound card to radio interface kit ON 4 KST chat page: www. on 4 kst. org/chat Slide deck will be put up on www. w 9 xt. com