Propagation Research

Another Amateur Radio activity by the South African Radio League


21 November  2014

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The 5 MHz Newsletter No 12

You can down this informative newsletter by Paul Gaskell here

Look at the latest WSPR activity from ZS1  

Stewart ZS6SGM's presentation at the Cape Town RTA certainly awakened interest in WSPR and the SARL Propagation research project


One of the most interesting findings is the inconsistency in the results of Near-vertical-incidence sky wave propagation (NVIS). Comparing a communications path between  two amateur stations, ZS6KN and ZS6KTS (distance of  51 km) it is interesting to note that  in June 2014 there was a good communications path  from just after 5 am till approximate 16:30  after which the signals disappeared.  The pattern for July was the same but signals were considerably stronger than during August and September.. During September a strong dip in signal strength can be seen. The other interesting observation from the graph is that propagation “opens” earlier and closes later as we go into summer which indicates variations in the  ionisation of the D layer of the ionosphere as the sun rises earlier and sets later. Not enough data has been collected to make any meaning full conclusions.  If the path was a pure ground wave the signals would have been more or less constant thought out the day and night. The article will be published in the November/December edition of EngineerIT and is already available on the web.

Read the article in EngineerIT here


Download Report

Change in frequency

Please note that the SARL allocation in the 5MHz band has been changed. 5250 kHz has changed to 5290 kHz.

Most WSPR stations have already changed. Please make sure you do not operate on 5250 kHz. No change to the 5260 kHz frequency




Almost a year ago the South African Radio League obtained a license from ICASA to do propagation search on 5 250 and 5 260 kHz to support the World Radio Conference (WRC15) agenda item 1.4  which will consider a possible new allocation to the amateur service on a secondary basis within the band 5 250 – 5 450 kHz. To support the agenda item propagation conditions, frequency sharing studies on the impact to other services currently allocated in the band and in the adjacent bands will need to be carried out.  Last year the SARL submitted a proposal to the Council of ICASA for the sponsorship of long term license The Council  granted the license to the SARL  last week. The SARL received the official license this week which is valid to 31 October 2015.

The Council of the SARL expressed its appreciation for the support from ICASA.

By: Stewart Moss ZS6SGM

Latest version V1.03 can now be down loaded here


If you are interested in the mysteries of propagation then WSPR is the tool at your disposal. To experience this fascinating tool, all you need is an SSB transceiver, simple antenna, a sound card interface to connect the transceiver to your computer and internet access. 

WSPR is short for Weak Signal Propagation Reporter and is pronounced “Whisper”. 

It is important to note right away that WSPR is not a QSO mode. It is used to broadcast a position, call sign and power level and see who hears and decodes it. The receiving station can work out how far the signal travelled and how strong it is on the receiving end.

The mode that WSPR uses is called MEPT-JT. MEPT means Manned Experimental Propagation Transmitter. The JT part is Joe Taylor's initials. Joe Taylor K1JT also developed the mode WSJT which is used for “moon-bounce” communication. In 1993 Joe Taylor shared a Nobel Prize in Physics with Russell Hulse, for some work they did in their field of Astrophysics. He obtained his license as an Amateur Radio operator as a teenager and as a result became interested in radio-astronomy.

This tutorial covers the reception and decoding of WSPR only. TX will be covered in later tutorial.   Download it here

Propagation research on 5 MHz some interesting results

Propagation Research undertaken by radio amateurs on 5 MHz shows some early and interesting results using the Weak Signal Propagation Reporter software (WSPR) . Read the article on the EngineerIT website. Put your browser here:

5MHz Newsletter

January Edition of 5 MHz Newsletter by Paul Gaskell, G4MWO

Download here

May edition of the 5MHz Newsletter by Paul Gaskell, G4MWO

Download here



The ionograms generated by the South African ionosonde network clearly illustrate the supremacy of the 5 MHz band for short range, near vertical incidence  skywave (NVIS) communications under certain conditions. These typically happens during the morning and late afternoon when the 7 MHz band does not support short range, sky wave communications and the 3.5 and 1.8 MHz bands suffer from high noise levels. 

During the middle of the day the 7 MHz (and 10 MHz during high solar activity) band is typically the most effective medium for short range, sky wave communications.

Permanent access to the 5 MHz band will ensure that the amateur radio community can efficiently contribute to emergencies requiring short distance communications beyond line-of-sight as typically required in hilly and mountainous terrain.

The South African ionosonde network is unique in Africa and place South African radio amateurs in the very fortunate position to monitor reigning, short range propagation conditions and to improve their skills and experience accordingly.

An article by Hannes Coetzee illustrated with ionograms is available for download  here

SARL Members  will have access to 5 250 and 5 260 kHz as well as 472 kHz on registration requiring the completion of a registration form which can be downloaded here.

Once completed please email it to Processing  time is a max three days.

All registered users will be listed  here

The SARL has been granted by the Independent Communications Agency  of South Africa (ICASA) access to two frequencies in the 5MHz band as well as 472 kHz . These pilot licenses are valid till 31 December 2013. It should be noted that use of these frequencies is limited only to Members of the South African Radio League

Maximum Bandwidth 3 kHz  Maximum power 100 Watt

Preferred mode USB/CW

SARL members may however also communicate with amateurs in other countries  outside South Africa with amateurs licensed to use 5MHz

5250 MHz  has been set aside  for various propagation research projects. Visit the this page for regular updates.

5260 MHz USB for general QSO's by SARL Members

World-wide 5MHz frequency listing download here