4X4XM's Sitemap

https://www.qsl.net/4x4xm updated: 15-May-2026
  1. ↑ Ham Radio Communications
  2. Navigation icon Simple and easy site navigation
  3. A collection of books, articles, and presentations on HF propagation
  4. Amateur radio operators by country (demographics, popularity)
  5. Ham radio propagation overview
  6. Ham radio range guide: How far can you talk?
  7. HF Propagation FAQ
  8. Prediction vs forecast of HF band conditions
  9. Radio books on HF propagation
  10. Regions vs. Layers: Earth's atmosphere and ionosphere
  11. Search terms for HF radio propagation
  12. Scientific and Technical Concepts You Should Know
    13.  
  13. Understanding HF Propagation:
    Forecast, Practice, Tutorial, Apps, Tools
    relaying dynamically online data with explanations.
    Featured by The DXZone.com
  14. Understanding HF Propagation - The latest static page
  15. Understanding HF Propagation - About
  16. Multilanguage: multilingual presentation
  17. Hebrew: התפשטות גלי רדיו בתחום ת"ג
  18. Webmaster: Doron, 4X4XM - Personal Bio
Propagation
  1. A comparison between Radio and Light propagation phenomena
  2. A Quick Guide to HF Propagation Using Solar Indices
  3. An introduction to HF propagation
  4. Amateur Radio Propagation Today
  5. Band Conditions
  6. Beginner's guide to HF radio propagation
  7. ChatGPT Compares forecasting tools for radio amateurs
  8. Compare DR2W propagation tool with VOACAP
  9. Current ham band conditions
  10. Current Ham Band Conditions Explained
  11. Current ham band propagation
  12. Current ham band propagation conditions
  13. Current ham radio conditions
  14. Current Hambands Conditions
  15. Current Ham Radio Condition Charts
  16. Current Ham Radio Propagation Charts
  17. Current Ham Radio Propagation Conditions
  18. Current HF Bands Conditions
  19. Current HF Propagation Conditions
  20. Current HF Propagation Map
  21. Current Propagation
  22. DX Band Conditions
  23. DX Conditions
  24. DX conditions today
  25. DX conditions now
  26. DX ham band conditions
  27. DX Propagation Online Map
  28. DX Propagation Prediction / Real-time HF Propagation Prediction
  29. DX radio propagation
  30. DX radio propagation explained
  31. Forecast ham band conditions
  32. Forecast short wave propagation conditions
  33. Forecasting propagation - tools for radio amateurs
  34. Ham Band Conditions | Ham band conditions
  35. Ham band map
  36. Ham condition chart
  37. Ham conditions
  38. Ham propagation
  39. Ham radio condition
  40. Ham radio condition map
  41. Ham Radio HF Propagation Real-time
  42. Ham Radio Propagation
  43. Ham Radio Propagation Charts
  44. Ham Radio Propagation Forecast
  45. Ham Radio Propagation map
  46. Ham Radio Propagation Now
  47. Ham Radio Propagation: Solar Conditions
  48. Ham radio QSO planner
  49. Ham radio secrets
  50. Ham Radio YouTube Channels skywave propagation
  51. Ham Solar
  52. Ham solar conditions
  53. HF bands allocated for radio amateurs and their characteristics
  54. HF bands open now
  55. HF Propagation
  56. HF Propagation App
  57. HF Radio Propagation Basics
  58. HF Propagation Calculator
  59. HF Propagation Chart
  60. HF Propagation Condition Map
  61. HF Propagation Conditions - Global and Regional
  62. HF Propagation Expert
  63. HF Propagation Explained
  64. HF propagation for beginners
  65. HF Propagation for Newbees
  66. HF Propagation for Newbies
  67. HF propagation for radio hams
  68. HF Propagation Forecast
  69. HF Propagation Forecast Bulletin
  70. HF Propagation Forecasting
  71. HF Propagation Modes
  72. HF Propagation Online Reports
  73. HF Propagation Overview
  74. HF propagation prediction tools
  75. HF Propagation Predictions
  76. HF Propagation Prediction Online
  77. HF Propagation Prediction Software
  78. HF Propagation Today
  79. HF Propagation Tools
  80. HF Propagation Widget
  81. HF Radio Propagation
  82. HF Radio Propagation for Radio Amateurs
  83. HF Radio Propagation Indices and Scales
  84. HF Radio Propagation Tutorials for Radio Amateurs
  85. HF Skywave Propagation For Radio Amateurs
  86. HF Radio Propagation Today
  87. Importance of HF Frequency Management
  88. Index of terms related to HF radio propagation
  89. Indicators of HF propagation and space weather
  90. Ionosphere Radio Wave Propagation (Skywaves)
  91. Ionospheric regional conditions
  92. Line of sight propagation
  93. Live solar events and past solar activity
  94. Local HF Conditions Matter More Than Global Space Weather Charts
  95. Mystery in wave propagation conditions
  96. NET vs. IRI ionospheric models
  97. Propagation conditions
  98. Propagation conditions for DX
  99. Propagation forecast
  100. Propagation indices
  101. Propagation of high frequency radio waves | The rebirth of HF
  102. Propagation of Short Radio Waves
  103. Propagation report
  104. Radio communication and the ionosphere
  105. Radio communication and the ionosphere
  106. Radio Communication Circuit
  107. Radio propagation charts
  108. Radio Propagation Forecast
  109. Radio Propagation Guide
  110. Radio Wave Propagation Forecasting
  111. Radio Wave Propagation Guide
  112. Real-time DX Reports * HF Propagation Prediction
  113. Real-time HF Propagation Reports
  114. Real-time propagation conditions
  115. Real-time propagation map
  116. Real-time radio propagation map
  117. Real-time Radio Propagation Reports
  118. Real-time reports of HF propagation
  119. Real-time reports of radio propagation
  120. Radio wave propagation today
  121. Real-time HF propagation charts
  122. Real-time reports of space weather
  123. Real-time space weather reports
  124. Shortwave Propagation
  125. Skywave concept
  126. Skywave Propagation Guide
  127. Skywave Propagation for Radio Amateurs
  128. Skywave Propagation Today
  129. Solar Activity & Ham Radio Propagation
  130. Solar Conditions & Ham Radio Propagation
  131. Solar Cycle Ham Radio
  132. Solar Flux Today
  133. Solar propagation
  134. Solar Storms Ham Radio
  135. Space wave propagation
  136. Space Weather Nowcast Serge Y. Stroobandt, ON4AA
  137. Space Weather Predictions
  138. The History of HF Propagation Models 1900s-2025
  139. The mystery of HF propagation
  140. The Rebirth of Shortwave Radio Communication
  141. The Solar Flux Today
  142. Tools for Forecasting and Predicting HF Propagation Conditions for Radio Amateurs
  143. Types of radio wave propagation
  144. Understanding CF vs MUF
  145. Understanding Band Conditions Banners
  146. Understanding HF radio
  147. Understanding HF Radio Propagation
  148. Understanding LUF and MUF
  149. Understanding Skywave Propagation
  150. Using radio beacons for tracking HF propagation
  151. Weather influence on HF radio propagation
FAQ
  1. At what Kp index can I see aurora?
  2. Can HF Radio Propagation be predicted?
  3. How are current band conditions?
  4. How Can We Forecast HF Propagation Conditions?
  5. How do HF propagation indices correlate with solar activity, geomagnetic activity, and space weather?
  6. How do I find out what bands are open?
  7. How do radio waves propagate?
  8. How do solar flares cause geomagnetic storms?
  9. How do the seasons affect HF radio propagation?
  10. How does space weather affect ham radio?
  11. How does the ionosphere affect HF Radio Propagation?
  12. How long does it take for Solar Wind to reach earth?
  13. How to determine if a band is open?
  14. How to read propagation charts?
  15. What are band conditions banners?
  16. What are DX clusters?
  17. What are electromagnetic waves?
  18. What are Geomagnetic Disturbances?
  19. What are Geomagnetic Storms?
  20. What are HF band conditions?
  21. What are ham band conditions?
  22. What are ionospheric clouds?
  23. What are ionospheric conditions?
  24. What are ionospheric storms?
  25. What are propagation indices?
  26. What are Radio Blackouts?
  27. What are Radio Waves?
  28. What are Solar Flares?
  29. What are Solar Storms? How they induce Geomagnetic Storms?
  30. What are sprites in Earth's atmosphere?
  31. What are Sunspots?
  32. What are the forecasting tools for HF radio propagation?
  33. What are the modes of HF Radio Propagation?
  34. What are the most common modes of HF Radio Propagation?
  35. What are the Solar Indices?
  36. What causes geomagnetic storms?
  37. What causes HF propagation?
  38. What causes ionospheric ionization?
  39. What factors influence HF Radio Propagation?
  40. What is Geomagnetic Activity?
  41. What is a geomagnetic disturbance?
  42. What is a Geomagnetic Storm?
  43. What is Earth magnetosphere?
  44. What is grayline propagation?
  45. What is ham radio communications?
  46. What is Ham Radio Propagation?
  47. What is HF Propagation
  48. What is HF Radio Propagation?
  49. What is HF Radio Propagation Prediction?
  50. What is HF Wave Propagation?
  51. What is ionization, in the context of HF radio propagation?
  52. What is LUF?
  53. What is MUF? How to predict MUF?
  54. What is NVIS? » Real-time NVIS Propagation Map
  55. What is plasma?
  56. What is radio?
  57. What is radio propagation?
  58. What is radio spectrum?
  59. What is sky wave propagation?
  60. What is skywave propagation?
  61. What is solar activity?
  62. What is solar flux?
  63. What is solar flux index?
  64. what is solar wind?
  65. What is Space Weather?
  66. What is the minimum usable frequency (LUF)?
  67. What is the current MUF?
  68. What are the current HF Propagation Conditions?
  69. What is the difference between geomagnetic and ionospheric storms?
  70. What is the difference between global and regional HF propgation conditions?
  71. What is the difference between solar indices and propagation indices?
  72. What is the difference between solar proton flux and solar proton density?
  73. What is the difference between the Greyline and the Solar Terminator?
  74. What is the difference between the Magnetosphere and Earth's magnetic field?
  75. What is the interplanetary magnetic field (IMF)
  76. What is the magnetic field of Earth?
  77. What is the T index?
  78. What is total electron content (TEC)?
  79. When will HF band conditions improve?
  80. When will HF propagation conditions improve?
  81. When will propagation on HF improve?
  82. Which ham band is open now?
  83. Which ham bands are open now?
  84. Why are ham bands closed?
  85. Why is geomagnetic activity important for ham radio?
  86. Why is HF used for long range communication?
A collection of books, articles, and presentations 1965-2025
  1. A Beginners Guide To Radio Propagation, Karl T. Thurber, W8FX (Popular Electronics 1998)
  2. A Primer on Space Weather - NOAA SWPC 2020
  3. A Simplified Model for HF Radio Wave Propagation for Middle East Region - Halid A. Hadi, et al.(2014)
  4. Australian Space Weather Alert System (2024)
  5. Basic Radio Wave Propagation by Nor Hadzfizah Binti Mohd Radi Faculty of Electric & Electronics Eng, Malaysia (2017)
  6. Comparing Ionospheric MUF using IRI16 Model with Mid Latitude—Ala'a A. Al-Shallal, et at., Univ of Baghdad, Iraq (2020)
  7. Correlation Between The Sunspot Numbers and Geomagnetic Parameters for The Solar Cycle 24
  8. Correlation analysis of Solar activity and Cosmic ray; J.Phys.Conf. (2017)
  9. Correlation-of-Sunspot-Numbers-and-Geomagnetic-Indices-with-Various-Climate-Change-Parameters-2024
  10. Critique of IONCAP's Reliability and Service Probability Calculations (1993)
  11. Detection-and-Localization-of-F-layer-Ionospheric-Irregularities-2022
  12. Discover the Magic of HF Radio; Norm Fusaro, W3IZ(2005)
  13. Equatorial-Spread-F_Ionospheric-dynamics-1962
  14. Geomagnetic-storm-and-equatorial-spread-F-2004
  15. HF Propagation tutorial by Bob Brown, NM7M, Ph.D. from U.C.Berkeley (2007)
  16. High Frequency Communications – An Introductory Overview - Who, What, and Why? by Bill Foose, Harris-Intersil 2012
  17. HF Propagation 2, 4Z1VC Prof Yosi "Yosi" Pinhasi (2025)
  18. HamSCI: Space Weather Operational Resources and Needs of the Amateur Radio Community (2020)
  19. Introduction to HF Propagation (Part1) by Rick Fletcher, W7YP (presented at FVARC September 16, 2025)
  20. Introduction to HF Radio Propagation Australian Gov. (2002)
  21. Introduction to HF Radio Propagation Australian Gov. (2007)
  22. Introduction to Ionospheric Modeling; Bruno Nava Presentation (2020)
  23. Ionospheric Propagation; Prof. Sean Victor Hum (2018)
  24. Ionospheric Radio Propagation by Kenneth Davies (1965)
  25. John Ashworth Aatcliffe; 12 December 1902 - 25 October 1987
  26. Modeling the Topside Ionosphere Observations by Satellites (2003)
  27. NOAA’s Space-Based Space Weather Observations (2023) Erin Lynch and Nai-Yu Wang
  28. NVIS: Stephen C. Finch, AI0W (2008)
  29. Noji Article: Understanding the Band Conditions Banner; 2018-12-05
  30. Propagation Modes—Presentation, Ken Larson, KJ6RZ (2024)
  31. Propagation and Radio Science, KL7AJ, ARRL (2005)
  32. Radio Wave Propagation part 1 Introduction Marcel H De Canck ON5AU 2002
  33. Radio Waves and the Ionosphere G3YWX QST 1999
  34. Rebirth of HF by Paul Denisowski, Product Management Engineer (KO4LZ) Rohde & Schwarz 2020
  35. Sky Wave Propagation unknown author ch4 2010
  36. Regional and Long Distance Skywave Communications by Ken Larson KJ6RZ 2025
  37. Solar UV and X ray spectral diagnostics 2018
  38. Skywave Radio Intro Kenneth N. Larson, KJ6RZ (2025-7-11)
  39. Space weather effects on communications systems, June 2020, Mark MacAlester, CISA
  40. Stanley article of the month QST June 2021
  41. Suggested Correlation Formula between High Possible Frequency (HPF) and Optimum Maximum Usable Frequency (OPMUF) over Middle East(2012)
  42. The Big Gun's Guide to Low Band Propagation A book by Bob Brown, NM7M 2002
  43. The Little Pistol's Guide to HF Propagation by Bob Brown, NM7M, Worldradio Books (1996)
  44. The Mysteries of HF Radio-Statewide-Nets-D-Layer-Gordon-Gibby-KX4Z(2020)
  45. The New Dxers Handbook Third Edition, by Bryce K. Anderson, KL7UA, May 2021
  46. Understanding LF and HF propagation by G0KYA, G3NYK; RSGB (2010)
  47. Understanding Propagation by Paul L. Herrman, N0NBH; 11 July 2010
  48. Understanding Propagation by M. Landress, WB5ANN, April 2022
  49. Understanding Solar Indices by Ian Poole, G3YWX - QST - September 2002
Shortcasts — short podcasts
  1. Index of 4x4xm's Shortcasts
  2. Aurora Propagation MP3 Sound
  3. Backscatter Radio Propagation MP3 Sound
  4. Field-Aligned Irregularities Propagation MP3 Sound
  5. HF skywave propagation for amateur radio MP3 Sound 9 minutes
  6. HF skywave propagation for amateur radio MP4 Video 9 minutes
  7. HF skywave propagation for amateur radio Script
  8. Ionospheric Regions Solar Index Skywave Propagation MP3 Sound
  9. Meteor Scatter Radio Propagation MP3 Sound
  10. Propagation Modes Review MP3 Sound
  11. Propagation of radio waves explained MP3 Sound
  12. Propagation of radio waves summary MP3 Sound
  13. Solar activity and tools for radio hams MP4 Video 6 minutes
  14. Sporadic E Propagation MP3 Sound
  15. The fascinating world of HF skywave propagation
  16. Transequatorial Propagation MP3 Sound
  17. What Are Radio Waves? MP3 Sound
Find below audio clips in various languages (in alphabetical order):
  1. 50 languages.txt
  2. Arabic | عربي: التنبؤ بظروف الاتصال لهواة الراديو
  3. Chinese | 中国人: 预测无线电爱好者的通信条件 - 无线电波传播
  4. Dutch | Nederlands:
    Voorspelling van communicatievoorwaarden voor radioamateurs
  5. French | Français:
    Prévision des conditions de communication pour les radioamateurs
  6. German | Deutsch:
    Vorhersage der Kommunikationsbedingungen für Funkamateure
  7. Hebrew | עברית:
    חיזוי התפשטות גלי רקיע - גלים בתדר גבוה (ת"ג) - חובבי רדיו - תנאי תקשורת
  8. Hindi | हिंदी: ेडियो शौकीनों के लिए संचार स्थितियों का पूर्वानुमान लहर प्रसार
  9. Italian | italiana:
    Previsione delle condizioni di comunicazione per radioamatori
  10. Japanese | 日本語: アマチュア無線家の通信状況を予測する
  11. Korean | 한국인: 아마추어 무선 통신 조건 예측
  12. Persian Farsi.txt | Farsi-long-text.txt
  13. Portuguese | Português:
    Previsão de condições de comunicação para radioamadores
  14. Spanish | española:
    Predicción de las condiciones de comunicación para radioaficionados
  15. Russian | Русский:
    Прогнозирование условий связи для радиолюбителей распространение волн
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