Sporadic E (Es) propagation

Working amateur radio on 50 MHz (6m), 70 MHz (4m), and 145 MHz (2m) via sporadic E (Es) is an exciting way to achieve long-distance contacts—especially across Europe and into North Africa and the Middle East—without needing high power or large antennas. The most fun in my opinion is in SSB and FM contacts although some prefer sticking to digital modes. Here’s how to time your operation, understand the nature of Es, and adopt best working practices.

Understanding Sporadic E (Es)

Sporadic E is caused by dense patches of ionization in the E-layer (around 90–130 km altitude). These patches reflect VHF signals over distances typically ranging from 600–2200 km, sometimes more with multi-hop.

Frequencies Affected:

• 50 MHz (6m): Most frequent Es band. Regular every year.
• 70 MHz (4m): Needs stronger ionization. Opens slightly less often than 6m.
• 145 MHz (2m): Much rarer. Es at 2m requires exceptionally strong events.

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Timing and Incidence of Openings

Best Seasons

• Late May to mid-August (Northern Hemisphere Es season).
• Peak activity: Around the summer solstice (June 15–30).
• A secondary winter Es season sometimes occurs in December–January, mainly below 50 MHz.

Daily Patterns

• Es peaks often follow this pattern:
  • Late morning: 09:00–11:00 UTC
  • Afternoon spike: 14:00–17:00 UTC
  • Occasional late evening events up to 21:00 UTC

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Best Working Practices

1. Monitoring & Early Alerts

• Use DX clusters: DXMaps, PSKReporter, and DXHeat
• Watch 6m FT8 activity as an Es “early warning” for potential 4m and 2m openings
• Keep an eye on real-time MUF maps (Maximum Usable Frequency), especially over 100 MHz
• Look in the mornings for activity on 70 MHz. If present than I have found 144 MHz Es is possible during the day.

2. Modes & Frequencies

Band	Mode	Common Es Frequencies
50 MHz	SSB, CW, FT8	50.130 USB (SSB), 50.313 (FT8)
70 MHz	SSB, CW, FT8	70.200 USB (SSB), 70.154 (FT8)
145 MHz	SSB, CW, FT8	144.300 USB (SSB), 144.174 (FT8

3. Calling Technique

• Use short, efficient callsigns and reports
• Avoid long CQ calls during marginal openings
• Grid square exchange is essential on FT8, e.g., JO01, KN34, etc.
• Monitor several frequencies (split receiver, SDR waterfall view) if possible

4. Be Ready!

• Keep equipment on and tuned to the right frequency during peak hours
• Have macros pre-prepared in WSJT-X for FT8
• Record or log signal reports even if no QSO—good data for propagation study

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Equipment Tips

• 50/70 MHz: Modest antennas (dipoles, small Yagis) and 50–100W are enough
• 145 MHz: High-gain Yagis (e.g., 9–13 elements) and high elevation help; Es here is rare, so fast QSO techniques (e.g. FT8, CW) are critical

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Typical Paths from UK (JO01)

• 50 MHz: Into southern Europe, Eastern Europe, Baltic, North Africa, and Middle East
• 70 MHz: Similar paths but fewer openings; more selective
• 145 MHz: Only during very strong Es—often to Italy, the Balkans, or Spain

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Summary: Working Es on VHF

Element	Recommendation
Timing	May–August, 09–17 UTC
Band Focus	50 MHz → 70 MHz → 145 MHz as Es strengthens
Modes	FT8 for weak/short openings, SSB for traditional DX
Tools	DXMaps, PSKReporter, WSJT-X, good logbook
Antennas	Yagis (2m/4m), horizontal polarization preferred
Etiquette	Short calls, efficient exchanges, quick QSL/logging

I hope you find this useful. I am posting it during the summertime Sporadic E season but bear in mind Es can be present as late as September as well as around the winter solstice.