4X4XM's Site Map

https://www.qsl.net/4x4xm updated: 7-November-2025
  1. ↑ Ham Radio Communications
  2. Navigation icon Simple and easy site navigation
  3. HF Propagation FAQ
  4. Ham Radio Propagation Overview
  5. Ham Radio Range Guide: How Far Can You Talk?
  6. Prediction vs Forecast of HF Band Conditions
  7. Regions vs. Layers: Earth's Atmosphere and Ionosphere
  8. Search Terms for HF Radio Propagation
  9. Scientific and Technical Concepts You Should Know
    10.  
  10. Understanding HF Propagation:
    Forecast, Practice, Tutorial, Apps, Tools
    relaying dynamically online data with explanations.
    Featured by The DXZone.com
  11. Understanding HF Propagation - The latest static snapshot
  12. Understanding HF Propagation - About
  13. Multilanguage: multilingual presentation
  14. Hebrew: התפשטות גלי רדיו בתחום ת"ג
  15. 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. ChatGPT Compares forecasting tools for radio amateurs
  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 conditions
  13. Current Hambands conditions
  14. Current ham radio condition charts
  15. Current HF Bands Conditions
  16. Current HF Propagation Conditions
  17. Current propagation
  18. DX band conditions
  19. DX conditions
  20. DX conditions now
  21. DX ham band conditions
  22. DX Propagation Online Map
  23. DX Propagation Prediction / Real-time HF Propagation Prediction
  24. Forecast ham band conditions
  25. Forecast short wave propagation conditions
  26. Forecasting propagation - tools for radio amateurs
  27. Ham band conditions
  28. Ham band map
  29. Ham conditions
  30. Ham propagation
  31. Ham radio condition
  32. Ham radio condition map
  33. Ham Radio HF Propagation Real-time
  34. Ham Radio Propagation
  35. Ham Radio Propagation Charts
  36. Ham Radio Propagation Forecast
  37. Ham Radio Propagation map
  38. Ham Radio Propagation Now
  39. Ham Radio Propagation: Solar Conditions
  40. Ham radio QSO planner
  41. Ham Radio YouTube Channels skywave propagation
  42. Ham Solar
  43. Ham solar conditions
  44. HF bands allocated for radio amateurs and their characteristics
  45. HF bands open now
  46. HF Propagation
  47. HF Propagation App
  48. HF Propagation Calculator
  49. HF Propagation Chart
  50. HF Propagation Condition Map
  51. HF Propagation Conditions - Global and Regional
  52. HF Propagation Expert
  53. HF Propagation Explained
  54. HF propagation for beginners
  55. HF Propagation for Newbees
  56. HF Propagation for Newbies
  57. HF propagation for radio hams
  58. HF Propagation Forecast
  59. HF Propagation Forecasting
  60. HF Propagation Modes
  61. HF Propagation Online Reports
  62. HF Propagation Overview
  63. HF propagation prediction tools
  64. HF Propagation Predictions
  65. HF Propagation Prediction Online
  66. HF Propagation Prediction Software
  67. HF Propagation Today
  68. HF Propagation Tools
  69. HF Propagation Widget
  70. HF Radio Propagation
  71. HF Radio Propagation for Radio Amateurs
  72. HF Radio Propagation Indices and Scales
  73. HF Radio Propagation Tutorials for Radio Amateurs
  74. HF Skywave Propagation For Radio Amateurs
  75. HF Radio Propagation Today
  76. Importance of HF Frequency Management
  77. Index of terms related to HF radio propagation
  78. Indicators of HF propagation and space weather
  79. Ionosphere Radio Wave Propagation (Skywaves)
  80. Ionospheric regional conditions
  81. Live solar events and past solar activity
  82. NET vs. IRI ionospheric models
  83. Propagation conditions
  84. Propagation forecast
  85. Propagation indices
  86. Propagation of high frequency radio waves | The rebirth of HF
  87. Propagation of Short Radio Waves
  88. Propagation report
  89. Radio communication and the ionosphere
  90. Radio communication and the ionosphere
  91. Radio Communication Circuit
  92. Radio propagation charts
  93. Radio Propagation Forecast
  94. Radio Wave Propagation Forecasting
  95. Real-time DX Reports * HF Propagation Prediction
  96. Real-time HF Propagation Reports
  97. Real-time propagation conditions
  98. Real-time propagation map
  99. Real-time radio propagation map
  100. Real-time Radio Propagation Reports
  101. Real-time reports of HF propagation
  102. Real-time reports of radio propagation
  103. Radio wave propagation today
  104. Real-time HF propagation charts
  105. Real-time reports of space weather
  106. Real-time space weather reports
  107. Shortwave Propagation
  108. Skywave concept
  109. Solar Activity & Ham Radio Propagation
  110. Solar Conditions & Ham Radio Propagation
  111. Solar Cycle Ham Radio
  112. Solar Flux Today
  113. Solar propagation
  114. Solar Storms Ham Radio
  115. Space Weather Nowcast Serge Y. Stroobandt, ON4AA
  116. Space Weather Predictions
  117. Skywave Propagation for Radio Amateurs
  118. Skywave Propagation Today
  119. The Rebirth of Shortwave Radio Communication
  120. The Solar Flux Today
  121. Tools for Forecasting and Predicting HF Propagation Conditions for Radio Amateurs
  122. Types of radio wave propagation
  123. Understanding CF vs MUF
  124. Understanding Band Conditions Banners
  125. Understanding HF Radio Propagation
  126. Understanding LUF and MUF
  127. Understanding Skywave Propagation
  128. 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 solar flares cause geomagnetic storms?
  8. How do the seasons affect HF radio propagation?
  9. How does space weather affect ham radio?
  10. How does the ionosphere affect HF Radio Propagation?
  11. How long does it take for Solar Wind to reach earth?
  12. How to determine if a band is open?
  13. What are band conditions banners?
  14. What are DX clusters?
  15. What are electromagnetic waves?
  16. What are Geomagnetic Disturbances?
  17. What are Geomagnetic Storms?
  18. What are HF band conditions?
  19. What are ionospheric clouds?
  20. What are ionospheric conditions?
  21. What are ionospheric storms?
  22. What are propagation indices?
  23. What are Radio Blackouts?
  24. What are Radio Waves?
  25. What are Solar Flares?
  26. What are Solar Storms? How they induce Geomagnetic Storms?
  27. What are sprites in Earth's atmosphere?
  28. What are Sunspots?
  29. What are the forecasting tools for HF radio propagation?
  30. What are the modes of HF Radio Propagation?
  31. What are the most common modes of HF Radio Propagation?
  32. What are the Solar Indices?
  33. What causes geomagnetic storms?
  34. What causes HF propagation?
  35. What causes ionospheric ionization?
  36. What factors influence HF Radio Propagation?
  37. What is Geomagnetic Activity?
  38. What is a geomagnetic disturbance?
  39. What is a Geomagnetic Storm?
  40. What is Earth magnetosphere?
  41. What is grayline propagation?
  42. What is ham radio communications?
  43. What is Ham Radio Propagation?
  44. What is HF Propagation
  45. What is HF Radio Propagation?
  46. What is HF Radio Propagation Prediction?
  47. What is HF Wave Propagation?
  48. What is ionization, in the context of HF radio propagation?
  49. What is LUF?
  50. What is MUF? How to predict MUF?
  51. What is NVIS? » Real-time NVIS Propagation Map
  52. What is plasma?
  53. What is radio?
  54. What is radio propagation?
  55. What is radio spectrum?
  56. What is sky wave propagation?
  57. What is skywave propagation?
  58. What is solar activity?
  59. What is solar flux?
  60. What is solar flux index?
  61. what is solar wind?
  62. What is Space Weather?
  63. What is the current minimum usable frequency (LUF)?
  64. What is the current MUF?
  65. What are the current HF Propagation Conditions?
  66. What is the difference between geomagnetic and ionospheric storms?
  67. What is the difference between global and regional HF propgation conditions?
  68. What is the difference between solar indices and propagation indices?
  69. What is the difference between solar proton flux and solar proton density?
  70. What is the difference between the Greyline and the Solar Terminator?
  71. What is the difference between the Magnetosphere and Earth's magnetic field?
  72. What is the interplanetary magnetic field (IMF)
  73. What is the magnetic field of Earth?
  74. What is the T index?
  75. What is total electron content (TEC)?
  76. When will HF band conditions improve?
  77. When will HF propagation conditions improve?
  78. When will propagation on HF improve?
  79. Which ham band is open now?
  80. Which ham bands are open now?
  81. Why are ham bands closed?
  82. Why is HF used for long range communication?
Books, Articles, and 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. HF Propagation tutorial by Bob Brown, NM7M, Ph.D. from U.C.Berkeley (2007)
  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 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
  46. 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. Arabic | عربي: التنبؤ بظروف الاتصال لهواة الراديو
  2. Chinese | 中国人: 预测无线电爱好者的通信条件 - 无线电波传播
  3. Dutch | Nederlands: Voorspelling van communicatievoorwaarden voor radioamateurs
  4. French | Français: Prévision des conditions de communication pour les radioamateurs
  5. German | Deutsch: Vorhersage der Kommunikationsbedingungen für Funkamateure
  6. Hebrew
    עברית: חיזוי התפשטות גלי רקיע - גלים בתדר גבוה (ת"ג) - חובבי רדיו - תנאי תקשורת
  7. Hindi | हिंदी: ेडियो शौकीनों के लिए संचार स्थितियों का पूर्वानुमान लहर प्रसार
  8. Italian | italiana: Previsione delle condizioni di comunicazione per radioamatori
  9. Japanese | 日本語: アマチュア無線家の通信状況を予測する
  10. Korean | 한국인: 아마추어 무선 통신 조건 예측
  11. Portuguese | Português: Previsão de condições de comunicação para radioamadores
  12. Spanish | española: Predicción de las condiciones de comunicación para radioaficionados
  13. Russian | Русский: Прогнозирование условий связи для радиолюбителей распространение волн
Total visits since 17 August 2022.

Repeat visits counted as new after 24 hours.

Flag counter site maybe down! all time
Visits (per day) since 17-August-2022
The number of site visits increased during
ionospheric events that disrupt HF radio propagation.


Visits (per day) during the last 3 months.


Visits (per day) during the last month.


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