Sun Type III/2 Radio Burst
May 11, 2014, 2237 UT


The Sun type III radio emission burst was observed with three instruments.

  • Tektronix MDO4104-6 spectrum analyzer being controlled by HP laptop with Python script to log screen captures.
  • Icom IC-R75 radio receiver with Radio-SkyPipe strip chart recorder.
  • RFSpace SDR-IQ Receiver with SpectraVue software.

Tektronix MDO4104-6 spectrum analyzer

  • The below Tektronix MDO4104-6 spectrum analyzer display shows the Sun radio emissions from 17.5 MHz to 24.0 MHz.
  • The Sun radio emission is the thin white blueish horizontal line just above the bottom of the blue spectrogram window.
  • The first set of strong vertical signals from the left edge are the 17.5 MHz to 17.9 MHz broadcasting stations.
  • The two horizontal lines in the middle of the spectrogram are strong lighting or strong RFI bursts.
  • The short horizontal lines in the spectrogram are weak lighting or weak RFI bursts.
  • The antenna sensitivity peaks on the left side of the spectrogram.
    • This results in the background noise being a lighter blue color and it is the vertical broad white-blue band on the left side of the spectrogram.

Tektronix MDO4104-6 Spectrum Analyzer Video

Sun radio emissions

United States Frequency Allocations

United States Frequency Allocations

Strongest Solar Radio Burst Captured with the Spectrum Analyzer

  • The spectrogram does not show the burst very clearly because it is on the bottom next to the window divider to the bottom spectrum trace window.
Sun radio emissions

Spectrum Analyzer Summary

Antenna East-West Dipole and Sun position

The above spectrum trace shows approximately a ~3 to ~5 dB rise in nose level for the strongest Sun radio emission signal acquired at 22:37:23 UT. The Sun was only 20.88 degrees above the horizon when the solar radio emission occurred.

Tektronix MDO4104-6 spectrum analyzer.

  • 17.5 MHz start frequency
  • 20.75 MHz center frequency
  • 24.0 MHz stop frequency
  • 6.5 MHz frequency span
  • 6.5 MHz capture bandwidth
  • 100 Hz resolution bandwidth
  • 650 kHz per horizontal division
  • 5 dBm per vertical division
  • ~7 seconds spectrum update rate
  • Spectrogram bottom is the current spectrum trace shown at the bottom of the display.
  • Spectrogram top is the oldest spectrum, approximately 30 minutes after the current spectrum trace at the bottom.
  • Date and time in lower right corner is in UT.

Tektronix  MDO4104-6

Spectrum Analyzer Equipment

Icom IC-R75 Radio Receiver Strip Chart

  • Icom IC-R75 radio receiver with Radio-SkyPipe II strip chart recorder
Sun radio emissions

Radio Equipment

  • Icom IC-R75
    • 20.1MHz
    • LSB
    • AGC off
    • Preamp 2 on
  • Behringer XENYX 302USB 5-Input Mixer with XENYX Mic Preamp and USB/Audio Interface
    • The HP laptop does not have a line input, only mic input.
    • XENYX 302USB works great taking the IC-R75 back recorder jack [REC] signal and digitizing it.
    • The XENYX 302USB has its own Line gain control.
    • The XENYX 302USB has its own headphone gain control.
  • MFJ Enterprises MFJ-1040C Preselector
  • Radiowavz 15-DP11 15M dipole antenna with 1:1 Balum


RFSpace SDR-IQ Receiver

  • In the center of the spectrogram the solar radio emission peaked at ~22:37:16 UT.
  • Compare below spectroagram with the Icom IC-R75 strip chart.
  • SpectraVue V3.28 software.
  • Radiowavz 15-DP11 15M dipole antenna with 1:1 Balum
  • HP Pavilion dv7 Notebook PC, 64-bit, Windows 7 Home Premium SP1
  • Ridiculously Simple NTP Client by Wolfgang "Wolf" DL4YHF for time keeping
Sun radio emissions

Observing Information

  • OBS-Time: May 11, 2014, 2237 UT
  • OBS-Location: Camas, WA USA, 16.6 miles East-North-East from the center of Portland, OR, USA

Radio JOVE Data Archive Calendar

Verifying Solar Burst

NOAA/ National Weather Service
National Centers for Environmental Prediction
Space Weather Prediction Center
Solar Event Reports (Edited Events)

  • Solar burst began at 2237 UT and ended at 2237 UT
  • Reporting observatory SAG: Sagamore Hill, MA, USA
  • Event RSP: Sweep-frequency radio burst
  • Frequency: 20 MHz to 57 MHz
  • Particulars: type III burst of major intensity 2
    • Type III burst: Fast drift burst.
    • 2 is significant intensity rating

:Product: 20140511events.txt
:Created: 2014 May 14 0332 UT
:Date: 2014 05 11
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
# Please send comments and suggestions to SWPC.Webmaster@noaa.gov 
# Missing data: ////
# Updated every 30 minutes.
#                            Edited Events for 2014 May 11
#Event    Begin    Max       End  Obs  Q  Type  Loc/Frq   Particulars       Reg#
7760       2237   ////      2237  CUL  C   RSP  020-057   III/2                


  • NASA WIND-WAVES: The Radio and Plasma Wave Investigation on the WIND Spacecraft
  • NASA STEREO (Solar TErrestrial RElations Observatory)