Site Map

https://www.qsl.net/4x4xm
Updated: 2025, November 11
  1. 4X4XM, Doron Tal - Personal Bio
  2. 4x4XM's Site Map — HF propagation for Radio Amateurs
  3. Simple and easy site navigation
  4. Forecast HF Propagation for Radio Amateurs
  5. Ham Radio Range Guide: How Far Can You Talk?
  6. Understanding HF Propagation: Forecast, Practice, Tutorials, Apps and Tools Dynamical online data
  7. Understanding HF Propagation - The latest static snapshot
  8. Understanding HF Propagation - About
  9. Ham Radio Propagation Overview
  10. Search Terms for HF Radio Propagation
  11. Index of technical terms related to skywave radio propagation
Amateur Radio Bands
  1. HF bands allocated for radio amateurs and their features
  2. IARU-R1-HF-bandplan-(2019).pdf
  3. Israel-Amateur-Radio-Frequencies-HF-29-9-2024.pdf
  4. RSGB-Band-Plan-13-6-2025.pdf
  5. US-Amateur-Radio-Bands-2-8-2024.pdf
Propagation
  1. A Quick Guide to HF Propagation Using Solar Indices
  2. A comparison between Radio and Light propagation phenomena
  3. Amateur Radio Propagation Today
  4. An introduction to HF propagation
  5. Band Conditions
  6. Blackout of HF communication
  7. Compare DR2W propagation tool with VOACAP
  8. Current ham band conditions
  9. Current ham band conditions explained
  10. Current ham band propagation
  11. Current ham band propagation conditions
  12. Current ham radio condition charts
  13. Current ham radio conditions
  14. Current Ham Radio Propagation
  15. Current Ham Radio Propagation Charts
  16. Current Ham Radio Propagation Conditions
  17. Current HamBands Conditions
  18. Current HF Bands Conditions
  19. Current HF Propagation Conditions
  20. Current propagation
  21. Current Shortwave Propagation Conditions
  22. Current Solar Events and Past Solar Activity
  23. DX band condition
  24. DX band conditions
  25. DX conditions
  26. DX conditions now
  27. DX ham band conditions
  28. DX Propagation Forecasting
  29. DX Propagation Online Map
  30. DX Propagation Map
  31. Forecast ham band conditions
  32. Forecast Shortwave Propagation Conditions
  33. Forecasting tools for HF radio propagation
  34. Geomagnetic Storms
  35. Global-and-Regional-HF-propagation-Conditions.htm
  36. Ham conditions
  37. Ham propagation
  38. Ham Radio Propagation
  39. Ham Radio Propagation map
  40. Ham Solar
  41. Ham solar conditions
  42. HF bands open now
  43. HF Propagation Conditions - Global versus Regional
  44. HF Propagation
  45. HF Propagation App
  46. HF Propagation Calculator
  47. HF Propagation Condition Map
  48. HF Propagation Expert
  49. HF Propagation Explained
  50. HF Propagation Forecast
  51. HF Propagation Live Map
  52. HF Propagation Modes
  53. HF Propagation Online Reports
  54. HF Propagation Overview
  55. HF Propagation Prediction Online
  56. HF Propagation Prediction Software
  57. HF Propagation Prediction
  58. HF propagation prediction tools
  59. HF Propagation Today
  60. HF Propagation Tools
  61. HF Propagation Widget
  62. HF Propagation Forecasting
  63. HF Propagation for Newbees
  64. HF Propagation for Newbies
  65. HF Propagation Indices
  66. HF Radio Propagation Chart
  67. HF Radio Propagation Today
  68. HF Radio Propagation
  69. HF Radio Propagation Tutorials
  70. HF bands allocated for radio amateurs and their characteristics
  71. HF propagation Online Map
  72. HF propagation map
  73. HF propagation for beginners
  74. HF propagation for radio hams
  75. HF radio propagation for radio amateurs
  76. HF radio propagation index
  77. Ham Radio HF Propagation real-time map
  78. HF propagation app
  79. HF propagation calculator
  80. HF propagation chart
  81. HF propagation explained
  82. HF propagation forecast.htm
  83. HF propagation map
  84. HF propagation prediction online
  85. HF propagation prediction software
  86. HF propagation today
  87. HF propagation widget
  88. Ham Radio Propagation Forecast
  89. Ham Radio Propagation Now
  90. Ham Radio Propagation Overview
  91. Ham Radio Propagation: Solar Conditions
  92. Ham band conditions
  93. Ham band condition for beginners
  94. Ham band map
  95. Ham radio condition
  96. Ham radio condition map
  97. Ham radio propagation forecast
  98. Ham radio QSO planner
  99. Ham Radio YouTube Channels skywave propagation
  100. Index of 4x4xm/Propagation
  101. Importance of HF Frequency Management
  102. Index of terms related to HF radio propagation
  103. Indicators of HF propagation and space weather
  104. Ionospheric regional conditions
  105. Line of sight propagation
  106. Live HF DX propagation maps
  107. Live HF propagation charts and maps
  108. Live HF propagation map
  109. Live HF propagation maps and charts
  110. Live radio propagation map
  111. LUF Propagation Chart
  112. LUF Propagation Map
  113. MUF Propagation Map
  114. MUF indices
  115. MUF indictors
  116. MUF propagation Online Map
  117. Minimum usable frequency chart
  118. NET vs. IRI ionospheric models
  119. Propagation conditions
  120. Propagation forecast
  121. Propagation of high frequency radio waves | The rebirth of HF
  122. Propagation report
  123. Radio amateur HF tutorial
  124. Radio Communication and the Ionosphere
  125. Radio Communication Circuit
  126. Radio propagation charts
  127. Radio Propagation Forecast
  128. Radio Propagation Forecasting
  129. Radio Wave Propagation Forecasting
  130. Radio Wave Propagation Today
  131. Radio-Frequency-Propagation-for-Ham-Radio.htm
  132. Real-time DX Reports * HF Propagation Prediction
  133. Real-time HF Propagation Charts
  134. Real-time HF Propagation Reports
  135. Real-time MUF Map
  136. Real-time propagation conditions
  137. Real-time propagation map
  138. Real-time radio propagation map
  139. Real-time Space Weather Reports
  140. Reports, Indices and Scales for HF Radio Propagation
  141. Shortwave Propagation
  142. Shortwave Radio Propagation Today
  143. Skywave concept
  144. Skywave Propagation for Radio Amateurs
  145. Skywave Propagation Today
  146. Solar Activity & Ham Radio Propagation
  147. Solar Conditions & Ham Radio Propagation
  148. Solar cycle ham radio
  149. Solar storms ham radio
  150. Solar propagation
  151. Space wave propagation
  152. Space Weather Predictions
  153. Space Weather Nowcast by Serge Y. Stroobandt, ON4AA, will open a new window
  154. The Ionosphere and Skywave Propagation
  155. The Rebirth of Shortwave Radio Communication
  156. The Solar Flux Today
  157. Tools for Forecasting and Predicting HF Propagation Conditions for Radio Amateurs
  158. Types of radio wave propagation
  159. Understanding HF Propagation - Review
  160. Understanding-HF-Propagation-Review
  161. Understanding HF Radio Propagation
  162. Understanding band conditions banners
  163. Understanding CF vs MUF
  164. Understanding LUF and MUF
  165. Understanding Skywave Propagation
  166. real-time-hf-propagation-map.htm
  167. real-time-ionosphere-map.htm
  168. understanding NVIS
  169. understanding hf radio
  170. Weather influence on HF radio propagation
FAQ
  1. HF Propagation FAQ @ root directory
  2. At-what-Kp-index-can-I-see-aurora
  3. Blackout of HF communication
  4. Can HF Radio Propagation be predicted?
  5. Compare-DR2W-propagation-tool-with-VOACAP.htm
  6. Compare-HF-Propagation-Solar-Geomagnetic-Space-weather-indices.htm
  7. Compare-forecasting-tools-for-HF-radio-propagation.htm
  8. Compare-forecasting-tools-for-radio-amateurs.htm
  9. Forecasting-tools-for-radio-amateurs.htm
  10. Geomagnetic-Storms.html
  11. Global-and-Regional-HF-propagation-Conditions.htm
  12. Global vs Regional HF propagation-Conditions
  13. What is the difference between the Greyline and the Solar Terminator?
  14. HF Radio Propagation FAQ FAQ directory
  15. HF-radio-propagation-for-radio-amateurs.htm
  16. How are current band conditions?
  17. How Can We Forecast HF Propagation Conditions?
  18. How do I find out what bands are open?
  19. How do the seasons affect HF radio propagation?
  20. How do solar flares cause geomagnetic storms
  21. How do solar storms cause geomagnetic storms?
  22. How does space weather affect ham radio?
  23. How does the ionosphere affect HF Radio Propagation?
  24. How long does it take for Solar Wind to reach earth?
  25. How to determine if a band is open?
  26. Live Solar Events Past Solar Activity
  27. What are band conditions banners?
  28. What are DX clusters?
  29. What are electromagnetic waves?
  30. What are Geomagnetic Disturbances?
  31. What are Geomagnetic Storms?
  32. What are Radio Waves?
  33. What are HF band conditions?
  34. What are Radio Blackouts?
  35. What are Solar Flares?
  36. What are Solar Storms? How they induce Geomagnetic Storms?
  37. What are sprites in Earth's atmosphere?
  38. What are Sunspots?
  39. What are ionospheric clouds?
  40. What are ionospheric conditions?
  41. What are ionospheric storms?
  42. What are propagation indices?
  43. What are the Solar Indices?
  44. What are the modes of HF Radio Propagation?
  45. What are the most common modes of HF Radio Propagation?
  46. What are the modes of Radio Propagation?
  47. What are-the most common modes of HF Radio Propagation.htm
  48. What factors influence HF Radio Propagation?
  49. What causes geomagnetic storms?
  50. What causes HF propagation?
  51. What causes ionospheric ionization?
  52. What is the Current Minimum Usable Frequency?
  53. What is The Magnetic Field Of Earth?
  54. What is Earth's Magnetosphere?
  55. What is Geomagnetic Activity?
  56. What is a Geomagnetic Disturbance?
  57. What is a Geomagnetic Storm?
  58. What is Grayline propagation?
  59. What is ham radio communications?
  60. What is HF propagation?
  61. What is HF radio propagation?
  62. What is HF radio propagation conditions
  63. What is HF radio propagation prediction?
  64. What is HF wave propagation?
  65. What is ionization, in the context of HF radio wave propagation?
  66. What is LUF?
  67. What is MUF? How to predict MUF?
  68. What is NVIS? » Real-time NVIS Propagation Map
  69. What is radio?
  70. What is Radio Propagation?
  71. What Is Radio Spectrum?
  72. What is Sky Wave Propagation?
  73. What is Skywave Propagation?
  74. What is Solar Activity?
  75. What is Solar Flux?
  76. What is Solar Flux Index?
  77. What is Solar Wind?
  78. What is Space Weather?
  79. What is the interplanetary magnetic field (IMF)
  80. What is the T index?
  81. What is Total Electron Content?
  82. What is the Current Maximum Usable Frequency (MUF)?
  83. What is the Current Minimum Usable Frequency (LUF)?
  84. What-is-earth's-magnetosphere.htm
  85. What is Ham Radio Propagation?
  86. What is plasma?
  87. What is the solar flux index?
  88. What is the current HF propagation condition?
  89. What is the difference between Global and Regional HF propgation conditions?
  90. What is the difference between earth's magnetosphere and-earth's magnetic field
  91. What is the difference between The Magnetosphere and Earth's magnetic field?
  92. What is the difference between geomagnetic and ionospheric storms?
  93. What is the difference between solar indices and propagation indices?
  94. What is the difference between solar proton flux and solar proton density?
  95. When will HF band conditions improve?
  96. When will HF propagation conditions improve?
  97. When will propagation on HF improve?
  98. Which ham band is open now?
  99. Which ham bands are open now?
  100. Why are ham bands closed?
  101. Why is HF used for long range communication?
  102. hf-propagation-app.htm
  103. hf-propagation-calculator.htm
  104. hf-propagation-chart.htm
  105. hf-propagation-explained.htm
  106. hf-propagation-forecast.htm
  107. hf-propagation-map.htm
  108. hf-propagation-prediction-online.htm
  109. hf-propagation-prediction-software.htm
  110. hf-propagation-today.htm
  111. hf-propagation-widget.htm
  112. real-time-hf-propagation-map.htm
  113. real-time-ionosphere-map.htm
  114. understanding-NVIS.htm
  115. understanding-hf-radio.htm
Books-Articles-Presentations
  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, Makaysia (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. Equatorial-Spread-F_Ionospheric-dynamics-1962
  13. Geomagnetic-storm-and-equatorial-spread-F-2004
  14. High Frequency Communications – An Introductory Overview - Who, What, and Why? by Bill Foose, Harris-Intersil 2012
  15. HF Propagation 2, 4Z1VC Prof Yosi "Yosi" Pinhasi (2025)
  16. HamSCI: Space Weather Operational Resources and Needs of the Amateur Radio Community (2020)
  17. HF Propagation tutorial by Bob Brown, NM7M, Ph.D. from U.C.Berkeley (2007)
  18. Introduction to HF Propagation (Part1) by Rick Fletcher, W7YP (presented at FVARC September 16, 2025)
  19. Introduction to HF Radio Propagation Australian Gov. (2002)
  20. Introduction to HF Radio Propagation Australian Gov. (2007)
  21. Introduction to Ionospheric Modeling; Bruno Nava Presentation (2020)
  22. Ionospheric Propagation; Prof. Sean Victor Hum (2018)
  23. Ionospheric Radio Propagation by Kenneth Davies (1965)
  24. John Ashworth Aatcliffe; 12 December 1902 - 25 October 1987
  25. Modeling the Topside Ionosphere Observations by Satellites (2003)
  26. NOAA’s Space-Based Space Weather Observations (2023) Erin Lynch and Nai-Yu Wang
  27. NVIS: Stephen C. Finch, AI0W (2008)
  28. Noji Article: Understanding the Band Conditions Banner; 2018-12-05
  29. Propagation Modes by Ken Larson, KJ6RZ (2024)
  30. Propagation and Radio Science, KL7AL, ARRL (2005)
  31. Radio Wave Propagation part 1 Introduction Marcel H De Canck ON5AU 2002
  32. Radio Waves and the Ionosphere G3YWX QST 1999
  33. Rebirth of HF by Paul Denisowski, Product Management Engineer (KO4LZ) Rohde & Schwarz 2020
  34. Sky Wave Propagation unknown author ch4 2010
  35. Regional and Long Distance Skywave Communications by Ken Larson KJ6RZ 2025
  36. Solar UV and X ray spectral diagnostics 2018
  37. Space weather effects on communications systems, June 2020, Mark MacAlester, CISA
  38. Stanley article of the month QST June 2021
  39. Suggested Correlation Formula between High Possible Frequency (HPF) and Optimum Maximum Usable Frequency (OPMUF) over Middle East(2012)
  40. The Big Gun's Guide to Low Band Propagation A book by Bob Brown, NM7M 2002
  41. The Little Pistol's Guide to HF Propagation by Bob Brown, NM7M, Worldradio Books (1996)
  42. The New Dxers Handbook Third Edition, by Bryce K. Anderson, KL7UA, May 2021
  43. Understanding LF and HF propagation by G0KYA, G3NYK' RSGB (2010)
  44. Understanding Propagation by Paul L. Herrman, N0NBH; 11 July 2010
  45. Understanding Propagation by M. Landress, WB5ANN, April 2022
  46. Understanding Solar Indices by Ian Poole, G3YWX - QST - September 2002
ChatGPT
  1. ChatGPT "failure" helped a Radio Amateur, 13-April-2023
  2. ChatGPT suggested updates for this website 15-April-2023
  3. ChatGPT response: webpage fixed; 18-April-2023
  4. ChatGPT learns about forecasting tools for radio amateurs
  5. ChatGPT review on 20-July-2025 HF Propagation
  6. ChatGPT review on 25-July-2025 HF Propagation
  7. ChatGPT review on 28-July-2025 HF Propagation
HAARP
  1. Benefits of the HAARP Project for Radio Hams
Other Languages
  1. التنبؤ بظروف الاتصال لهواة الراديو
  2. 预测无线电爱好者的通信条件 - 无线电波传播
  3. Voorspelling van communicatievoorwaarden voor radioamateurs
  4. Prévision des conditions de communication pour les radioamateurs
  5. Vorhersage der Kommunikationsbedingungen für Funkamateure
  6. रेडियो शौकीनों के लिए संचार स्थितियों का पूर्वानुमान लहर प्रसार
  7. Previsione delle condizioni di comunicazione per radioamatori
  8. アマチュア無線家の通信状況を予測する
  9. 아마추어 무선 통신 조건 예측
  10. Previsão de condições de comunicação para radioamadores
  11. Predicción de las condiciones de comunicación para radioaficionados
  12. Прогнозирование условий связи для радиолюбителей распространение волн
עברית Hebrew
  1. אטמוספירת כדור הארץ והשפעתה על התפשטות גלי רדיו
  2. התפשטות גלי רדיו בתחום ת"ג—HF
  3. התפשטות גלי רדיו בתחום ת"ג (תקציר)
  4. חיזוי התפשטות גלי רקיע - גלים בתדר גבוה (ת"ג) - חובבי רדיו - תנאי תקשורת
  5. חיזוי התפשטות גלי רקיע - גלים בתדר גבוה (ת"ג) - חובבי רדיו - תנאי תקשורת pdf
  6. שאלות של חובב רדיו מתחיל בנושא התפשטות גלים קצרים
Shortcasts
  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