The VK4RTT beacon is back on air from Mt Coot-tha, Brisbane, on 144.440 as of yesterday, 12 March, 2022.
It transmits 3 CW IDs, straight carrier then a JT4D sequence.
To decode JT4D on WSJT-X, you need to enable the box marked "Enable VHF and submode features" in File/Setup. (Thanks Peter VK5PJ !)
Select JT4 from the Mode menu then set Submode to D from the options box to the right of the FTol box.
I manually set the radio to 144.438500/USB to get the 1500Hz tones required on the waterfall and to decode.
eg 2323 -13 -0.0 1437 $* VK4RTT QG62LM
Doug VK4ADC
After the rectification of some issues, VK4RTT 50.285MHz and 144.440MHz is back operational from Mt Coot-tha.
[
attachment=572]
And to quote Peter VK4EA....
"For those unaware of the frequencies, 50.285 and 144.440 MHz, alternating between carrier, CW and digital modes. JT65c on 6 metres and JT4d on 2 metres.
Antennas are cross dipoles horizontally polarised, about 100W on 6 and 60W on 2m. Feeder length is minimal, return loss on both antennas is better than 25dB. Signals should They should be cleary heard throughout SE Qld and Northern NSW via ground wave.
The whole shebang is managed by a ZL-PLL beacon controller by Wayne Knowles (ZL2BKC), frequency disciplined by a GNSS receiver providing a 10MHz reference. The PAs are managed by Arduino Nano based controllers designed and built by George (VK4AMG) providing metering and protection. Another Arduino controller implemented by George provides overall management and remote monitoring for the box. Future plans are to have remote monitoring via the Internet, I have already run a single mode bundle of fibre to the main building. So if you have the gear or know somebody with a fusion splicer willing to terminate a few cores, please let me know ?. Unfortunately there is a moratorium on using ISM wifi links, which is a shame as I have LOS from house to the site and a few spare Ubiquiti’s looking for an application.
Full details here -
http://brisbanevhfgroup.com/wp-content/u...19-1-1.pdf
Next big project is to install the air con, no real rush now the weather is lot milder.
Also evaluating whether we can have the 4RBB microwave beacons at the same site, there are mechanical challenges to be enable easy maintenance and avoiding the need to climb towers.
Reception reports welcome here, BookFace and/or
vkspotter.com.
Cheers,
Peter - VK4EA"