Propagation USA-VK

Summary:

Using WSPR reports,looking for the best time for Arizona-VK propagation.

Propagation USA-VK

AA7FV 20 Aug 2017 06:40

My 1-watt WSPR transmitter has been operating on 30m every half-hour, 24 hours a day (except when I'm on CW myself.) This is a plot of WSPR reports on 30m received from VK for 18th and 19th August. My station is in Tucson, in southern Arizona in the SW of the USA.

The horizontal scale is time, UTC and the vertical scale is the relative s/n of my WSPR signal received in VK.

For VK7, around 05:00 to 07:00 UTC seems to be a good time for me. 06:00 was good for VK5DG, with a very weak report for me, but it's not clear for the few other VK5 reports.

Just satisfying my own curiosity.

73
Darrel, aa7fv.

Re: Propagation USA-VK

AA7FV 28 Aug 2017 23:09

Last night (2017-08-28) it seemed to be particularly good for Arizona-VK propagation on 30m. Here's a plot of s/n vs time (UTC) from all VK WSPR reports on AA7FV, for the last 24 hours.

For reference, here is how the VK stations giving me reports were distributed:

Cheers,
Darrel, aa7fv.

Re: Propagation USA-VK

AA7FV 20 Aug 2017 19:07

To put my VK 30m WSPR reports into context: I am using a rhombic beam, aimed at Europe from Arizona. The rhombic is unterminated, which means that there is a back lobe almost as strong as the main forward lobe. Unfortunately, VK is on the side of that back lobe, so in my VK WSPR reports there is a strong bias towards the East and South of Australia.
Here's the quadrant of the 30m beam pattern that includes ZL and most of VK, superposed on a Great Circle map centred on AA7FV, in southern Arizona.

I only wish that I could rotate the beam.

73
Darrel, aa7fv.

Re: Propagation USA-VK

VK5EEE 21 Aug 2017 13:48

Beautiful map OM Darrel! It looks like I'm not far off the deep null on the back of your Rhombic. I can't see, how much is the gain in that null and how does that compare to a dipole I wonder?

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77 de Lou, VK5EEE

Re: Propagation USA-VK

AA7FV 28 Aug 2017 22:46

In that null, at the best elevation it's about the same as a dipole in free space - so still workable.
Cheers,
Darrel.