24GHz Contact Aided By A Strong Inversion

[VK3HZ]

The conditions today to VK7 were such that at about 0910 local time, Rex VK7MO in Devonport and I (on John's Hill) had an SSB contact on 24 GHz - a distance of 372.5 km and a new VK record.
We then switched to Digital and monitored conditions for a few hours. The 24 GHz signal remained relatively steady until finally fading out at about 1100 local.

This is a view of the inversion from my location:

Interestingly, I was getting max signal strength with the dish pointing just above the top of the inversion layer (yes, the dish is sharp).

Regards,
Dave
VK3HZ

[VK4GHZ]

Well done, Dave.
A great achievement.

Were you watching Hepburn?

[VK4UH]

Congratulations Rex and David.

Great Effort - Great Result

KJ VK4UH

[VK2ZRH]

Well done Dave and Rex!

Keep pushing those boundaries.

[VK4OX]

Yes, well done Rex and David.

A quick search for the World Record, 24GHz terrestrial, (human to human) qso found 544km. So Rex and David's qso is right up there. A fantastic achievement.

Onwards and Upwards.
Adrian VK4OX.

[VK3OE]

Well Done David and Rex.

Love the picture from Dunns Hill with the inversion in the background. This inversion has been around for a few days. Coming home last night I could clearly see the top of the inversion against the Dandenongs at around 400m. This is quite unusual. Further, as I came up the hill, the temperature increased till around 400m, and then settled down after that with no further increase. At 10:00 am today the humidity at Ferny Creek (above the inversion) was 7%, an excellent set of conditions for 24GHz.

check out http://weather.uwyo.edu/cgi-bin/soundin ... &STNM=ymml

for the vertical sounding at 0:00 Z today, the inversion is obvious.

73
Andrew
VK3OE/VK3OER

[VK3BQ]

Well done guys. We are down at anglesea. And have had a huge cloud of sea mist over us most if the day. It's off shore now. But very thick. I had vk7 146 and 439mhz repeaters playing wia news all the way down the coast while driving.


Sent from my iPad using Tapatalk

[VK4OE]

Good on you, fellows!

As Adam suggests, there just had to be something great happening today, and you two fellows clearly recognised this and went out and took advantage of it! I wonder if there is currently any enhancement across the wider expanse of water up to VK3ZQB and/or VK5DK who both have home stations set up on 24 GHz.

Such inversions do occur in many places from time to time around this big country - it'll be great for all of us when more fellows are able to operate there!

There's always more just over the horizon.....congrats on this one!

--Doug Friend, VK4OE.

[VK3HZ]

Yes, we've been watching Hepburn for a while, looking for something like this weekend.

In anticipation of good conditions, on Friday Rex went north to Table Cape near Wynyard. That afternoon, from John's Hill, 10GHz signals were rock crushing - 59+ when aimed directly and R5 signals just about anywhere I pointed the dish. We then set up on 24GHz and had a contact at reasonable levels (-14). Signals came up and at 1745 local, we worked on SSB with 5x2/5x1 reports over a distance of 339.2 km - a new National record.

On Saturday, Rex had moved to the hills behind Burnie - a 358 km path. While signals were again very strong on 10 GHz, there was no sign of a signal on 24 GHz. It was late in the morning by the time we tried 24GHz, so perhaps we had missed the window and the heat had broken up the conditions. There were visible signs of a duct, but quite turbulent compared to Sunday (see below)

On Sunday, Rex was now near Devonport and we started early and on 24GHz. Our SSB contact was at 0910 local. However, there was only a relatively short period when conditions were good enough for SSB. While the inversion was very visible from my end, Rex reported clear skies. Looking at the Hepburn chart, a very high level of enhancement is shown at the John's Hill end of the path, dropping significantly as it gets to the Tasmanian coastline.

One thing this weekend reinforced is that 10GHz and 24GHz are vastly different bands. Characteristics of the 10GHz band are similar to the lower microwave bands. However, 24GHz is hard work!

Regards,
Dave.

[VK7DB]

On Saturday, Rex had moved to the hills behind Burnie - a 358 km path

On my Grandparents farm in Stowport. I was present for some of that event By chance I found Rex on Table Cape the night before and arranged to try from Stowport.

Dion
VK7DB