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VHF 2 meters tropo test in South Indian Ocean


The goal of this page is to help promotion of VHF/UHF path exploration in our zone. We try to concentrate all useful information for that purpose, and help to get contact in case of openning. If you have any information or comment to share, please feel free to contact us, you are welcomed.

Beacons transmitting on 2 meters in our area.

Call FR5DN/B ZS2VHF ZS4AFV ZS5LEE ZS6BBD ZS3OBE ZS1NAZ ZS3TG ZS6WAB ZS6SRL VK6RBU/B
Location FR5DN qra - AVIRONS PORT ELIZABETH BLOEMFONTIEN DURBAN ALLDAYS SPRINGBOK CAPE TOWN KURUMAN POLOKWANE JOHANNESBURG PERTH
Grid LG78qs  KG26?? KG30cv KG50jf KG47mi JG80wi JF96gc KG12mh KG46rc KG33wv PERTH
TRX FT-2500M    ? ? ? ? ? ? ? ? ? ??
QRG 144.400  144.410 144.415 144.420 144.425 144.430 144.435 144.440 144.445 144.460 144.560
Mode CW  FM FM FM FM FM FM FM FM FM FSK
Power out - W 120 ? ? ? ? ? ? ?? ? ? 10
Coax loss - db 1  ? ? ? ? ? ? ? ? ? ?
Antenna Type Horizontal beam 17el    ? ? ? ? ? ? ? ? ? Horizontal beam
Antenna gain - dbd 13.0   ? ? ? ? ? ? ? ? ? ?
Radiated power - w ERP 1800    ? ? ? ? ? ? ? ? ? 100
Azimuth 245 to ZS   ? ? ? ? ? ? ? ? ? To ZS
Active YES YES YES YES YES YES YES YES ON REQUEST - also  432.445 YES YES
Contact FR5DN ZS2?? ZS4AFV ZS5LEE ZS6BBD ZS3OBE ZS1NAZ ZS3TG ZS6WAB ZS6SRL VK6HK

The world centered on Reunion Island - LG78qs.

Thanks to Gabriel F6DQM for use of map generated with his Aziworld software.

 

Close view of possible south tropo ducting DX?

 

Of course, other countries are potential candidates for tropo or other modes : South of India (4200km), Maldives (3300km), west coast of Indonesia (5200km), Seychelles (1850km),  Chagos (2500km),  Marion (3200km). No need to say that Madagascar (800km), Tromelin (600km), Rodrigues (855km) should be workable several times per year.

All this means that Reunion seems quite well situated for extended propagation tests over the Indian Ocean. The major issue is to get stations qrv, both from Reunion, and from DX countries.

Another problem is due to the fact that Reunion is having large high mountains just in the middle of the land, blocking DX paths. But this may be a chance too, to go portable to the best altitude for entering the duct! So one has to be on the right coast to look for some particular azimuth. Situated on the SW coast, I have free sea horizon from 150 to 350° to the west.

The best way to explore paths is to get high ERP (1kw or +). One must not conclude that path is non existant because of too low power. Kw erp can be achieved with 50w at dipole of 13dbd antenna, say a 17el yagi. Stacking of short antennas is also a nice solution, depending on target ; vertical stacking for low elevation angle and broad azimuth, and horizontal stacking for small azimuth angle. 

Links of interest


Tropospheric forecast :
The Hepburn maps for ZS or 5R8 to FR path is HERE
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Weather data :
The surface pressure chart for our area is HERE  (South African Weather Service)

Current and forecast surface pressure chart is HERE (Center for Ocean-Land-Atmosphere Studies - COLA)

The Australian bureau of meteorology  with current and archive weather charts is HERE

The partial visible weather picture is HERE

Other satellit weather picture is HERE (ZS-FR) or HERE  for Indian Ocean
----------------------

Radiosounding data :
The  University of Wyoming world sounding data are HERE

For another source  in our area clic HERE (Univertity of Cologne) and then on the area of interest.

The NOAA forecast sounding is HERE



This chart down there can help to determine the altitude of the T° inversion layer vs the pressure.




To come (file not ready yet):
Clic HERE to get  a collection of computed data for Antanarivo, Tromelin, Port Elisabeth and Durban.

Reports 2008


 - On 06th May 2008, ZS2GK, Glenn in KF47kt, heard some faint cw at 17h20 UTC (19h20 SAST - 21h20 in FR5).  There was fast qsb. It could be the first reception of a possible DX path between ZS and FR. FR5DN/b ERP was about 560w.

- ZS5LEE has his beacon towards FR5 from 15/04 to 15/05/2008. No decode has been made on my side.

- Openning of 12 August 2008 : ZS2GK, Glenn in KF47kt, heard the FR5DN/B beacon from before 08h45z to 10h15z. I copied Glenn SSB at 41-51 report, but we lost each others. See HERE for complete story.

- Openning of 14 August 2008 early morning : see HERE.

- Short openning of 02 September 2008 : Report from Glenn, ZS2GK : HERE
"The beacon was in and out of the noise from about 19:40UTC until it faded at 20:20 UTC, just not good enough to have a QSO and that was with the pre-amp running".





- Visual inversion layers as flying between 3B8 and FR (25/10/2008) : see HERE.


- Some soundings results : see HERE.
Reports 2009
- 28 February 2009 - ZS2GK : see HERE.
- 26-28 August 2009 - South Madagascar propagation : see HERE.

- 01-02 September 2009 - FIRST ZS<->FR digital qso : see HERE.

- 04 September 2009 - Nice forecast but...why no qso?? : see HERE.

- 06 September 2009 -  High altitude tropo above my qth? : see HERE.

- 17 September 2009 - South Madagascar propagation : see HERE.

- 20/21/22 October 2009 - Nice 600km+ propagation : see HERE.

- 10 November 2009 - Nice 700km+ propagation from 1130z to 1730z  with good vhf rx from Tamatave harbour



Reports 2010


- 09/10 February 2010 - 2m digital and SSB with ZS2/ZS5 and FIRST EVER 70cms QSO : see HERE.



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