Duct Opening 13.07.04

On Tuesday evening, conditions began to build up from about 7.30pm.

I had an OK signal from the Adelaide beacon 144.450 peaking around 5/5 at 750 km.
Also there was Mount Gambier 144.550 peaking around 5/2 at 630 km.

No one seemed to be available for a contact in Adelaide, but to my southwest I worked Colin VK5DK at Mount Gambier 5/4 @ 630 Km. Also Russell VK3ZQB at Port Fairy 5/3 @ 552 Km.

Repeaters around Adelaide were there but had QSB and also were weak most of the time, slightly strange. No repeaters available Mt Gambier way, not even from Ararat in the same direction.

Considering its the middle of Winter here, the most interesting part began about 11 pm when I had a listen for the VK6 beacons. I had Spectran running at the same time and some how I managed to catch a glimpse of lines running on the Spectran screen resembling the Esperance beacon transmission. (I have copied once before in February)

The Esperance beacon is VK6REP on 144.568 MHz, locator is PF06we, transmitting 10 watts FSK into a omni horizontal antenna.

The distance from here to the beacon is 2313 Km.

This was only copied visually on Spectran and despite my waiting to 3am it never came out of the noise to be audible.

At first I thought it was probably a birdie, so was quite sceptical. But after monitoring for a while, it started to become clear this was the real thing.

It would QSB away and come back again very slowly. You could see the FSK 100Hz shift keying. I was able to time the sequence and have this all verified by VK6 residents, VK6KZ and 6HK (also by VK3HZ).

I also saved Spectran screen captures of the signal and will probably put them and some info about this interesting occurance on my website shortly.

Signal from the Esperance beacon was virtually non existant around 3am, but QSB in and out for that whole 4 hours. I'd be quite sure that with a good station around that area we should have been able to complete a 2 way voice contact up here, if not, then certainly JT44 would have made it easy.


Leigh VK2KRR

In the weather map above, note - multiple linked cell centers; the eastern most 1035 pressure area is located right on Esperance; the weather fronts shown are well to the south of the path.