AUSTRALIAN SHORTWAVE JOURNAL

AUSTRALIAN SHORTWAVE RADIO JOURNAL

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Tuesday, December 13, 2016

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!
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

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