Propagation to 3Y0X Reality v Predictions

1. Propagation to 3Y0XReality v Predictions Steve Nichols G0KYA, RSGB Propagation Studies Committee www.qsl.net/g0kya

4. A few definitions: Solar Flux: A measure of the electromagnetic output from thesun, measured at a wavelength of 10.7cm (2800MHz). Sunspot Number: The number of observed sunspots and sunspot groups. A index: A daily average measure of the distortion of the earth’s magneticfield due to ions from the sun (flare material, CMEs, coronal holes etc). K Index: A three-hourly (logarithmic) measure of the distortion of theearth’s magnetic field due to ions from the sun (flare material, coronal holes etc).

5. Good: High solar flux (perhaps 150 – 200+) and low A/K indices Perhaps A less than 10 Bad: Low solar flux (less than 80) and high A/K indices Perhaps A more than 25

6. What about solar activity? Source: NOAA, Space Environment Center. Predicted Smoothed SSN = 18.4

7. What about geomagnetic activity? Source: NOAA, Space Environment Center, Middle Latitude - Fredericksburg

9. The three prediction programs: HamCap – as used on the 3Y0X web site. Uses the VOACAP engine (free) W6ELProp – the classic simple program fromSheldon Shallon (free) ACE-HF – a more sophisticated program using the VOACAP engine ($99)

11. HamCap

12. HamCap 20m 24-hour propagation (short path)

13. HamCap

14. HamCap

17. ACE-HF – Short-path, 80m,40m,30m 400W + three-element Yagi at both ends

18. ACE-HF – Short-path, 20m,17m,15m 400W + three-element Yagi at both ends

19. ACE-HF – Long-path, best cases 400W + three-element Yagi at both ends

20. So what could we conclude for 160-40m? • Both HamCap and ACE-HF say that 160m and 80m are total no-go areas, but W6ELProp says 80m possible • W6ELProp/ACE-HF say 40/30m may be possible – ACE HF says 30m is better All programs agree that you need a VERY decent antenna and power – QRPers need not apply!

21. So what could we conclude for 20-10m? • All programs agree that you need a VERY decent station – eg 400w and a tribander at 85 feet • Conditions are marginal at best, although best bands are: 20m short path 0200–0400, 0700-1000 and 1930-2200 • 17m short path 1300-2000hrs • 15m short path 1700-1930hrs 12m probability less than 20% (get used to white noise) 10m – wash the car/wait six years!

22. So what about 80m and 160? • Let’s make some intelligent (?) assumptions • You need a dark (night) path between the stations  • You need a low A and K Index  • Possibly low sunspot numbers?  • There good be greyline enhancement at UK sunrise  • Looking at mutual sunrise/sunset times then this • only gives: • 02:45hrs - 07:25hrs

23. With a big but! • The sun is never more than two degrees below the horizon at 3Y0X. • So, best “greyline” time from UK is therefore:06:40hrs – 07:25hrs • Actually, six minutes later at the beginning (07:28hrs),and 13 minutes earlier at the end (07:09hrs) – but calculate according to YOUR longitude.

24. The reality - 3Y0X to G

25. Top band/80m reality • Theory says contacts possible between 02:45hrs - 07:25hrs • Best “greyline” time is 06:40hrs – 07:25hrs • 160m • G3BJ 13.2.06 05:27hrs • G3KZR 15.2.06 06:38hrs  • G3XTT 13.2.06 07:09hrs  • G3SED 13.2.06 07:10hrs  • 80m • G3BJ 15.2.06 07:34hrs  (ish) 11.2.06 06:23hrs 13.2.06 06:50hrs  • G3SED 12.2.06  07:16hrs  • G0TSM 15.2.06 07:25hrs  • 17.2.06 07:12hrs  • 19.2.06 06:43hrs 

26. Top band - contacts v sunrise

27. Top band - contacts v K index Top band stationwas dismantled in preparation fordeparture.

28. Top band - contacts v sunspots Top band stationwas dismantled in preparation fordeparture.

29. 80m contacts v sunrise

30. 80m reality (W6ELProp) G3BJ 07:34 (sunrise 07:25)

31. 80m contacts v K Index

32. 80m - contacts v sunspot No.

33. 80m v 160m – any correlationby day? Top band stationwas dismantled in preparation fordeparture.

34. 80m v 160m -any correlation by time?

35. 40m reality v ACE-HF

36. 40m reality v W6ELProp

37. 30m/40m reality (ACE-HF)

38. 20m reality v ACE-HF (3el Yagi)

39. 20m reality v W6ELProp

40. 17m reality (ACE-HF)

41. 15m reality (ACE-HF + W6ELProp)

42. 15m/17m/20m reality (ACE-HF)

43. 12m reality (ACE-HF Yagi x 3el) Note: W6ELProp predicts no opening!

44. 12m reality (ACE-HF Yagi x 3el) So 12m opening came on a day with zero sunspot number, but after four days of SN>10

45. HF contacts v solar indices Notes: HF is 20-10m Solar data source: NOAA, Space Environment Center.

46. Stop Press: VOAProp

47. Conclusions [1] – MF propagation • On 160m and 80m the maximum number of contacts occurred at the time of lowest (zero) sunspot number/low K index. • Sunrise/pre-sunrise at the UK end provided the best opportunity for contacts on 160m, 80m and 40m. • A calculation of “best greyline” time for 80m would have proved very fruitful!

48. Conclusions [2] – HF propagation • HF contacts appeared to be mainly short path, but there was a significant number of long path contacts on 20m in the afternoon (13th/14th). • 17m, 15m, and 12m were textbook, following the predictions very closely indeed. • The best conditions appeared to be at times of zero sunspot number – this was when the big 12m opening occurred (12th) and when the 20m long path openings occurred (13th/14th).

49. Conclusions - software • Both HamCap (free) and ACE-HF ($99) did a pretty good job of calculating the HF possibilities, but did not predict Top Band/80m openings. • If using either, assume 400w and a Yagi to get a decentprediction. • W6ELProp also did a good job, but also highlighted the 80m openings – and its free! • My thanks to the 3Y0X team for a great Dxpeditionand for making me lose some sleep!

50. Useful web sites • This presentation – www.qsl.net/g0kya • HamCap - www.dxatlas.com/HamCap • ACE-HF - home.att.net/~acehf/ • W6ELProp - www.qsl.net/w6elprop/ • Geoclock - home.att.net/~geoclock/ • VOAProp – www.g4ilo.com