Site Map

https://www.qsl.net/4x4xm
Updated: 2025, October 21
  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, Tutorial, Apps, 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 Today
  59. HF Propagation Tools
  60. HF Propagation Widget
  61. HF Propagation Forecasting
  62. HF Propagation for Newbees
  63. HF Propagation for Newbies
  64. HF Propagation Indices
  65. HF Radio Propagation Chart
  66. HF Radio Propagation Today
  67. HF Radio Propagation
  68. HF Radio Propagation Tutorials
  69. HF bands allocated for radio amateurs and their characteristics
  70. HF propagation Online Map
  71. HF propagation map
  72. HF propagation for beginners
  73. HF propagation for radio hams
  74. HF radio propagation for radio amateurs
  75. HF radio propagation index
  76. Ham Radio HF Propagation real-time map
  77. HF propagation app
  78. HF propagation calculator
  79. HF propagation chart
  80. HF propagation explained
  81. HF propagation forecast.htm
  82. HF propagation map
  83. HF propagation prediction online
  84. HF propagation prediction software
  85. HF propagation today
  86. HF propagation widget
  87. Ham Radio Propagation Forecast
  88. Ham Radio Propagation Now
  89. Ham Radio Propagation Overview
  90. Ham Radio Propagation: Solar Conditions
  91. Ham band conditions
  92. Ham band condition for beginners
  93. Ham band map
  94. Ham radio condition
  95. Ham radio condition map
  96. Ham radio propagation forecast
  97. Ham radio QSO planner
  98. Ham Radio YouTube Channels skywave propagation
  99. Index of 4x4xm/Propagation
  100. Importance of HF Frequency Management
  101. Index of terms related to HF radio propagation
  102. Indicators of HF propagation and space weather
  103. Live HF DX propagation maps
  104. Live HF propagation charts and maps
  105. Live HF propagation map
  106. Live HF propagation maps and charts
  107. Live radio propagation map
  108. LUF Propagation Chart
  109. LUF Propagation Map
  110. MUF Propagation Map
  111. MUF indices
  112. MUF indictors
  113. MUF propagation Online Map
  114. Minimum usable frequency chart
  115. NET vs. IRI ionospheric models
  116. Propagation conditions
  117. Propagation forecast
  118. Propagation of high frequency radio waves | The rebirth of HF
  119. Propagation report
  120. Radio amateur HF tutorial
  121. Radio Communication and the Ionosphere
  122. Radio Communication Circuit
  123. Radio propagation charts
  124. Radio Propagation Forecast
  125. Radio Propagation Forecasting
  126. Radio Wave Propagation Forecasting
  127. Radio Wave Propagation Today
  128. Radio-Frequency-Propagation-for-Ham-Radio.htm
  129. Real-time DX Reports * HF Propagation Prediction
  130. Real-time HF Propagation Charts
  131. Real-time HF Propagation Reports
  132. Real-time MUF Map
  133. Real-time propagation conditions
  134. Real-time propagation map
  135. Real-time radio propagation map
  136. Real-time Space Weather Reports
  137. Reports, Indices and Scales for HF Radio Propagation
  138. Shortwave Propagation
  139. Shortwave Radio Propagation Today
  140. Skywave concept
  141. Skywave Propagation for Radio Amateurs
  142. Skywave Propagation Today
  143. Solar Activity & Ham Radio Propagation
  144. Solar Conditions & Ham Radio Propagation
  145. Solar cycle ham radio
  146. Solar storms ham radio
  147. Solar propagation
  148. Space Weather Predictions
  149. Space Weather Nowcast by Serge Y. Stroobandt, ON4AA, will open a new window
  150. The Ionosphere and Skywave Propagation
  151. The Rebirth of Shortwave Radio Communication
  152. The Solar Flux Today
  153. Tools for Forecasting and Predicting HF Propagation Conditions for Radio Amateurs
  154. Types of radio wave propagation
  155. Understanding HF Propagation - Review
  156. Understanding-HF-Propagation-Review
  157. Understanding HF Radio Propagation
  158. Understanding band conditions banners
  159. Understanding CF vs MUF
  160. Understanding LUF and MUF
  161. Understanding Skywave Propagation
  162. real-time-hf-propagation-map.htm
  163. real-time-ionosphere-map.htm
  164. understanding NVIS
  165. understanding hf radio
  166. 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 Sky Wave Propagation?
  72. What is Skywave Propagation?
  73. What is Solar Activity?
  74. What is Solar Flux?
  75. What is Solar Flux Index?
  76. What is Solar Wind?
  77. What is Space Weather?
  78. What is the interplanetary magnetic field (IMF)
  79. What is the T index?
  80. What is Total Electron Content?
  81. What is the Current Maximum Usable Frequency (MUF)?
  82. What is the Current Minimum Usable Frequency (LUF)?
  83. What-is-earth's-magnetosphere.htm
  84. What is Ham Radio Propagation?
  85. What is plasma?
  86. What is the solar flux index?
  87. What is the current HF propagation condition?
  88. What is the difference between Global and Regional HF propgation conditions?
  89. What is the difference between earth's magnetosphere and-earth's magnetic field
  90. What is the difference between The Magnetosphere and Earth's magnetic field?
  91. What is the difference between geomagnetic and ionospheric storms?
  92. What is the difference between solar indices and propagation indices?
  93. What is the difference between solar proton flux and solar proton density?
  94. When will HF band conditions improve?
  95. When will HF propagation conditions improve?
  96. When will propagation on HF improve?
  97. Which ham band is open now?
  98. Which ham bands are open now?
  99. Why are ham bands closed?
  100. Why is HF used for long range communication?
  101. hf-propagation-app.htm
  102. hf-propagation-calculator.htm
  103. hf-propagation-chart.htm
  104. hf-propagation-explained.htm
  105. hf-propagation-forecast.htm
  106. hf-propagation-map.htm
  107. hf-propagation-prediction-online.htm
  108. hf-propagation-prediction-software.htm
  109. hf-propagation-today.htm
  110. hf-propagation-widget.htm
  111. real-time-hf-propagation-map.htm
  112. real-time-ionosphere-map.htm
  113. understanding-NVIS.htm
  114. understanding-hf-radio.htm
Books-and-Articles
  1. A Beginners Guide To Radio Propagation, Karl T. Thurber, W8FX (Popular Electronics 1998)
  2. A Primer on Space Weather
  3. A Simplified Model for HF Radio Wave Propagation for Middle East Region (2014)
  4. An Introduction to Ionosphere and Magnetosphere (Abstract)
  5. Australian Space Weather Alert System (2024)
  6. Basic Wave Propagation. Nor Hadzfizah Binti Mohd Radi (2017)
  7. Comparing Ionospheric MUF using IRI16 Model with Mid Latitude (2020)
  8. Correlation Between The Sunspot Numbers and Geomagnetic Parameters for The Solar Cycle 24
  9. Correlation analysis of Solar activity and Cosmic ray; J.Phys.Conf. (2017)
  10. Correlation-of-Sunspot-Numbers-and-Geomagnetic-Indices-with-Various-Climate-Change-Parameters-2024
  11. Critique of IONCAP's Reliability and Service Probability Calculations (1993)
  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. Introduction to HF Radio Propagation Australian Gov. (2007)
  19. Introduction to Ionospheric Modeling; Bruno Nava Presentation (2020)
  20. Ionospheric Propagation; Prof. Sean Victor Hum (2018)
  21. Ionospheric Radio Propagation by Kenneth Davies (1965)
  22. John Ashworth Aatcliffe; 12 December 1902 - 25 October 1987
  23. Modeling the Topside Ionosphere Observations by Satellites (2003)
  24. HF Propagation tutorial by Bob Brown, NM7M, Ph.D. from U.C.Berkeley
  25. NOAA’s Space-Based Space Weather Observations (2023) Erin Lynch and Nai-Yu Wang
  26. NVIS: Stephen C. Finch, AI0W (2008)
  27. Noji Article: Understanding the band conditions banner; 2018-12-05
  28. Propagation Modes by Ken Larson, KJ6RZ (2024)
  29. Propagation and Radio Science, KL7AL, ARRL (2005)
  30. Radio Waves and the Ionosphere G3YWX QST 1999
  31. Radio Wave Propagation part 1 Introduction Marcel H De Canck ON5AU 2002
  32. Regional and Long Distance Ken Larson KJ6RZ 2010
  33. Sky Wave Propagation unknown author Ch4 2010
  34. Solar UV and X ray spectral diagnostics 2018
  35. Space-weather-effects-on-communications-systems-June-2020
  36. Stanley article of the month QST June 2021
  37. Suggested Correlation Formula between High Possible Frequency (HPF) and Optimum Maximum Usable Frequency (OPMUF) over Middle East(2012)
  38. The Big Gun`s Guide to Low Band Propagation A book by NM7M 2002
  39. The Little Pistol's Guide to HF Propagation_Robert R Brown_Worldradio Books_1996
  40. The New Dxers Handbook Third Edition, KL7UA, May 2021
  41. Understanding LF and HF propagation by G0KYA, G3NYK' RSGB (2010)
  42. Understanding Propagation by Paul L. Herrman, N0NBH; 11 July 2010
  43. Understanding Propagation WB5ANN
  44. 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