I posted this earlier this morning on the 160 Topband Reflector, with a few typo's. I'm reposting it here now with corrections and some additional information specifically for the MF broadcast band. Also I will not be publishing #2002-31 of the KN4LF 7 Day Medium Frequency Radio Propagation Outlook until sometime on Monday.
Due to the dismal Topband propagation conditions seen during the CQ WW contest last weekend, I've received numerous requests for and explanation of 160 meter propagation correlation with propagation indices. Unfortunately MF propagation is so complicated that the usual indices are not clear cut indicators of 160 meter propagation conditions, like with HF frequencies. However the following indices parameter levels will (((generally))) point to good 160 meter propagation conditions. 1.) Dropping indices numbers are better. 2.) Solar flux under 150, under 100 better, 70 is best for E layer multi hop. 3.) Solar flux of at least 100 for E valley-F layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, under 7 for several days consecutively is best. 5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for high latitude paths, 0-1 for several days consecutively is best. 6.) Energetic protons no greater then 10 MeV (10+0) for 160/120 meters and no greater then (10-1) on MF broadcast band. 7.) Background x-ray flux levels less than C2 for several days consecutively for 160/120 meters and less then C1 for MF broadcast band. No current STRATWARM alert. IMF Bz with a negative sign, indicates a better chance of high latitude path auroral absorption/unpredictable refraction or scattering of MF RF signals, when the Kp is above 3. See my MF radio propagation theory notes for more information http://www.kn4lf.com/kn4lf8.htm . 73, Thomas Giella, KN4LF/NNN0HUS Plant City, FL, USA KN4LF 160 Meter Amateur Radio Resources And More: http://www.kn4lf.com KN4LF Daily Solar Space Weather Geomagnetic Data Plus MF Propagation Outlook: http://www.kn4lf.com/kn4lf5.htm FL Meteorological & Climatic Institute: http://www.kn4lf.com/sub/fmci.htm FMCI 2002-2003 FL Daily Winter WX Discussion: http://www.kn4lf.com/sub/fmci17.htm --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.410 / Virus Database: 231 - Release Date: 10/31/2002 ---[Start Commercial]--------------------- Check out new HCDX web site: http://www.hard-core-dx.com/ ---[End Commercial]----------------------- ________________________________________ Hard-Core-DX mailing list [EMAIL PROTECTED] http://www2.hard-core-dx.com/mailman/listinfo/hard-core-dx http://www.hard-core-dx.com/ _______________________________________________ THE INFORMATION IN THIS ARTICLE IS FREE. It may be copied, distributed and/or modified under the conditions set down in the Design Science License published by Michael Stutz at http://dsl.org/copyleft/dsl.txt
