UNUSUAL HF DAYTIME PROPAGATION INTO MELBOURNE

UNUSUAL HF DAYTIME PROPAGATION INTO MELBOURNE

 

On December 2 2016, there was an excellent opening in the early-afternoon period on 9 and 11 MHz, from Africa the Middle East and Asia, across the time span extending from 0400 to 0500.

 

This propagation pattern becomes apparent in the Melbourne summer, during low-sunspot years, via what is known in the radio industry as "Specialized Complex Modes", in which transmission occurs over daytime paths, due to multiple reflections off the top of the (sporadic) E layer bouncing off the lower region of the F layer, with no intermediate ground bounce. This is marked by very strong signal strength, with very litle fading, on frequencies which do not normally propagate during this window.

 

The phenomenon has been observed by the writer, in Melbourne, since the late 1940s – its appearance is unpredictable, with signals "popping up" out of nowhere, of variable durations ranging from a few seconds to up to an hour, then to vanish just as quickly!

 

The study and analysis of this propagation mode had been a continued target for technical hobbyists over many years, and were well documented in the radio hobby newsletters of the time.

 

These days, there is negligible interest or involvement in coordinated HF technical monitoring in the Melbourne region!

 

The summary which follows was made on December 12, 2016, at a field site in the Warrandyte State Park in the Pound Bend Reserve, in Melbourne's outer east, with the small Eton E5 receiver, and  three metres of random antenna tossed into a bush. The The Yarra River is nearby. An echidna (Spiny Anteater) came out of the bushes to assist!

 

AFRICA 

9460 S. AFRICA BBC-Meyerton English

9885 SAO TOME Kirundi

11825 MADAGASCAR KNLS English

11995 MADAGASCAR BBC-Talata Somali

 

MIDDLE EAST

9700 TURKEY Turkish

9755 IRAN *0420 Hebrew

11730 OMAN BBC *0430 Persian

11860 S. ARABIA RF. Sannaa, Arabic

11875 IRAN Turkish *0425

12035 OMAN BBC English

12095 UAE BBC-Dhabbaya  English

12130 KUWAIT R. Mashaal Pashto

12140 KUWAIT R. Azadi Pashto

 

ASIA

9490 CHINA Xizang PBS Lhasa Tibetan

9595 JAPAN R. Nikkei, Japanese

9635 VIETNAM VOV Domestic Vietnamese

9730 MYANMAR Domestic, Burmese

9760 JAPAN. R. Nikkei, Japanese

9835 MALAYSIA RTM-Kajang Malay

9850 TAIWAN SOH, relay RFA, Chinese

9865 INDIA Hindi

11600 TAIWAN SOH Chinese relay RFA

11665 MALAYSIA RTM-Kajang Malay

11670 INDIA Persian (co-channel CNR2)

11735 N. KOREA KCBS Korean

11780 IRAN Hebrew *0425

11810 CHINA CNR8 Mongolian

11905 CHINA CNR6 Amoy

11950 CHINA Xizang PBS Lhasa Chinese

11980 KAZAKHSTAN  RFA-Dushanbe Chinese

12055 CHINA CNR17 Kazakh

12150 TAIWAN SOH Chinese relay RFA

 

Transmission path from Southern Africa

 

 

Monitoring Site

 

My assistant!