Site Map

https://www.qsl.net/4x4xm
Updated: 2025, November 22
  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. Ham band charts
  2. HF bands allocated for radio amateurs and their features
  3. IARU-R1-HF-bandplan-(2019).pdf
  4. Israel-Amateur-Radio-Frequencies-HF-29-9-2024.pdf
  5. RSGB-Band-Plan-13-6-2025.pdf
  6. 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 HF propagation map
  21. Current propagation
  22. Current Shortwave Propagation Conditions
  23. Current Solar Events and Past Solar Activity
  24. DX band condition
  25. DX band conditions
  26. DX conditions
  27. DX conditions today
  28. DX conditions now
  29. DX ham band conditions
  30. DX Propagation Forecasting
  31. DX Propagation Online Map
  32. DX Propagation Map
  33. Forecast ham band conditions
  34. Forecast Shortwave Propagation Conditions
  35. Forecasting tools for HF radio propagation
  36. Geomagnetic Storms
  37. Global-and-Regional-HF-propagation-Conditions.htm
  38. Ham conditions
  39. Ham propagation
  40. Ham Radio Propagation
  41. Ham Radio Propagation map
  42. Ham radio secrets
  43. Ham Solar
  44. Ham solar conditions
  45. HF bands open now
  46. HF Propagation
  47. HF Propagation App
  48. HF Radio Propagation Basics
  49. HF Propagation Calculator
  50. HF Propagation Condition Map
  51. HF Propagation Conditions - Global versus Regional
  52. HF Propagation Expert
  53. HF Propagation Explained
  54. HF Propagation Forecast
  55. HF Propagation Live Map
  56. HF Propagation Modes
  57. HF Propagation Online Reports
  58. HF Propagation Overview
  59. HF Propagation Prediction Online
  60. HF Propagation Prediction Software
  61. HF Propagation Prediction
  62. HF Propagation status and alerts
  63. HF propagation prediction tools
  64. HF propagation today
  65. HF propagation tools
  66. HF Propagation Widget
  67. HF Propagation Forecasting
  68. HF Propagation for Newbees
  69. HF Propagation for Newbies
  70. HF Propagation Indices
  71. HF Radio Propagation Chart
  72. HF Radio Propagation Today
  73. HF Radio Propagation
  74. HF Radio Propagation Tutorials
  75. HF bands allocated for radio amateurs and their characteristics
  76. HF propagation Online Map
  77. HF propagation map
  78. HF propagation for beginners
  79. HF propagation for radio hams
  80. HF radio propagation for radio amateurs
  81. HF radio propagation index
  82. Ham Radio HF Propagation real-time map
  83. HF propagation app
  84. HF propagation calculator
  85. HF propagation chart
  86. HF propagation explained
  87. HF propagation forecast.htm
  88. HF propagation map
  89. HF propagation prediction online
  90. HF propagation prediction software
  91. HF propagation today
  92. HF propagation widget
  93. Ham band conditions
  94. Ham band condition for beginners
  95. Ham band map
  96. Ham condition chart
  97. Ham radio condition
  98. Ham radio condition map
  99. Ham radio propagation forecast
  100. Ham radio propagation now
  101. Ham radio propagation overview
  102. Ham radio propagation: solar conditions
  103. Ham radio propagation forecast
  104. Ham radio QSO planner
  105. Ham Radio YouTube Channels skywave propagation
  106. The History of HF Propagation Models 1900s-2025
  107. Index of 4x4xm/Propagation
  108. Importance of HF Frequency Management
  109. Index of terms related to HF radio propagation
  110. Indicators of HF propagation and space weather
  111. Ionospheric regional conditions
  112. Line of sight propagation
  113. Live HF DX propagation maps
  114. Live HF propagation charts and maps
  115. Live HF propagation map
  116. Live HF propagation maps and charts
  117. Live radio propagation map
  118. LUF Propagation Chart
  119. LUF Propagation Map
  120. MUF Propagation Map
  121. MUF indices
  122. MUF indictors
  123. MUF propagation Online Map
  124. Minimum usable frequency chart
  125. Mystery in wave propagation conditions
  126. NET vs. IRI ionospheric models
  127. Propagation conditions
  128. Propagation conditions for DX
  129. Propagation forecast
  130. Propagation of high frequency radio waves | The rebirth of HF
  131. Propagation report
  132. Radio amateur HF tutorial
  133. Radio Communication and the Ionosphere
  134. Radio Communication Circuit
  135. Radio propagation charts
  136. Radio Propagation Forecast
  137. Radio Propagation Forecasting
  138. Radio Wave Propagation Forecasting
  139. Radio Wave Propagation Today
  140. Radio-Frequency-Propagation-for-Ham-Radio.htm
  141. Real-time DX Reports * HF Propagation Prediction
  142. Real-time HF Propagation Charts
  143. Real-time HF Propagation Reports
  144. Real-time MUF Map
  145. Real-time propagation conditions
  146. Real-time propagation map
  147. Real-time radio propagation map
  148. Real-time Space Weather Reports
  149. Reports, Indices and Scales for HF Radio Propagation
  150. Shortwave Propagation
  151. Shortwave Radio Propagation Today
  152. Skywave concept
  153. Skywave Propagation for Radio Amateurs
  154. Skywave Propagation Today
  155. Solar Activity & Ham Radio Propagation
  156. Solar Conditions & Ham Radio Propagation
  157. Solar cycle ham radio
  158. Solar storms ham radio
  159. Solar propagation
  160. Space wave propagation
  161. Space Weather Predictions
  162. Space Weather Nowcast by Serge Y. Stroobandt, ON4AA, will open a new window
  163. The Ionosphere and Skywave Propagation
  164. The mystery of HF propagation
  165. The Rebirth of Shortwave Radio Communication
  166. The Solar Flux Today
  167. Tools for Forecasting and Predicting HF Propagation Conditions for Radio Amateurs
  168. Types of radio wave propagation
  169. Understanding HF Propagation - Review
  170. Understanding-HF-Propagation-Review
  171. Understanding HF Radio Propagation
  172. Understanding band conditions banners
  173. Understanding CF vs MUF
  174. Understanding LUF and MUF
  175. Understanding Skywave Propagation
  176. real-time-hf-propagation-map.htm
  177. real-time-ionosphere-map.htm
  178. understanding NVIS
  179. understanding hf radio
  180. 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. Discover the Magic of HF Radio; Norm Fusaro, W3IZ(2005)
  12. Detection-and-Localization-of-F-layer-Ionospheric-Irregularities-2022
  13. Equatorial-Spread-F_Ionospheric-dynamics-1962
  14. Geomagnetic-storm-and-equatorial-spread-F-2004
  15. High Frequency Communications – An Introductory Overview - Who, What, and Why? by Bill Foose, Harris-Intersil 2012
  16. HF Propagation 2, 4Z1VC Prof Yosi "Yosi" Pinhasi (2025)
  17. HamSCI: Space Weather Operational Resources and Needs of the Amateur Radio Community (2020)
  18. HF Propagation tutorial by Bob Brown, NM7M, Ph.D. from U.C.Berkeley (2007)
  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, KL7AL, 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
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. החזר כמעט אנכי של גלי רקיע | חילה אנכית
  7. 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