1296Mhz Antenna Builds with VK7MO

The Build Group

From L-R VK7’s OO, BEN, ZBX, HRS and HH with their antennas. Photo: VK7MO

While many people enjoyed southern Tasmania’s Hobart Show public holiday, Rex VK7MO played host to a group of amateurs building antennas for 1296Mhz (23cm).

VK7s OO, BEN, ZBX, HRS and HH all attended from early in the morning to build Yagi’s suitable for 23cm. While most were content to built antennas with 18-21 elements, Richard VK7ZBX set himself a challenge in building a 70 (yes 70) element yagi, with a boom length of 6 metres!

The work is not over though, with building to continue on Saturday.

REAST Members visit the ABC Hobart Studios

REAST Members at ABC Hobart

A huge thank you to Damien VK7SD and Alan VK7KAD who were our fantastic hosts for the tour. Both Damien and Alan are technical support staff at the ABC and welcomed and showed us around.

We started in the live music recording studio which was being upgraded and then moved to radio studio 703 and were shown the control surfaces and control screens that make up an ABC radio studio. Everything is configurable and can be personalised for any presenter in the studio. Next door the ABC Radio Hobart presenter and producers were busy with the evening program.

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REAST Members learn about Virtual Reality

Ian Mackintosh Explaining Virtual Reality (Photo VK7TW)

It was standing room only and we had a visitor in VK2 Bob VK7BS who has moved down here and is about to become a member of REAST.

The room was setup in a theatre of the round configuration with a big table in the middle with three different Oculus Rift headsets (DK1, DK2 and CE1), computers, high power video cards, controllers and cameras.

Ian then took the audience through the video games that pioneered 3D and VR with Doom and Quake. We started to see standardised 3D gaming engines that most manufacturers adopted.

Ian Mackintosh started with a presentation on Virtual Reality (VR) Archeology. Starting in 1965 with Ivan Sutherland and Ian took the audience through the development of computer graphics and specifically three dimensional computer graphics. The VR boom took off in 1970-80s with Atari with arcade games which overtook the military applications and development. The game that took Atari to another level was Star Wars with vector graphics and Ian bought along service manual for this game. The 1990 saw NASA put resource toward VR along with Nintendo Virtual Boy and SEGA cockpit arcade game. But unfortunately each manufacturer would custom build and develop the hardware and software. Most of these were commercial failures. Ian then went through the VR Recipe including 3D hardware, multi-thread multi core processors, six degrees of freedom, 3D audio, etc.

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Radio Remote Control with Android

REAST member Vince Henderson VK7VH has written in with this excellent article on how he is using Pocket RxTx, an Android application, to remote control his Ts-2000 Radio.

A couple of years ago, I looked at the remote radio control Android app, called Pocket RxTx. It had many teething problems. I left it alone until it showed signs of being reliable.

The latest beta version caught my eye. The result is that I am now using the latest beta version of the app. It works very well. The app is written by Dan Toma, an Amateur Radio operator, YO3GGX. Full details of the app are available at his website www.yo3ggx.ro

The details of my set up are as follows –

Radio

TS2000 – CAT connection from radio rear com connector to PC RS-232 serial port. This is a straight type cable. Audio in/out and PTT is via an interface that connects to the 13 pin ACC2 port on the back of the radio. PTT via pin 9 PKS and pin 8 GND, mutes the front mic. Audio in (from interface) via pin 11 PKD and pin 12 GND. Audio out (to interface) via pin 3 MANO and pin 4 GND.

The Pocket RxTx website lists the radios that have been tested with the app. You will probably find your make and model of radio, in the list.

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Receiving Weather Satellite Images

Sean VK7FAZE has recently been experimenting with NOAA APT weather Satellite reception and shares his experiences with us in this article

False-colour image taken from NOAA-18 showing east coast of Australia

False-colour image taken from NOAA-18 showing east coast of Australia

There is not much more fascinating than getting pictures from space.  And with a but of smarts and some cheap bits and pieces it’s possible to do this quite easily.

One of the display pieces at REAST’s stand at this years Festival of Bright Ideas was a display showing how to receive weather satellite photos using some fairly easily obtainable bits and pieces – a computer with a ‘USB TV Dongle’ as the now classic Software Defined Radio, a simple but impressive looking Quadrafilar Helical Antenna, and software freely downloadable from the Internet.

The antenna is built out of PVC electrical conduit and a few fittings, some 75mm PVC storm drain, and some old co-ax cable left over from an old TV installation.  Some cutting and drilling, PVC glue and a couple of lazy hours on a Saturday afternoon and its done.

The software was a current version of Ubuntu Linux and the latest copy of GQRX fresh from the authors repository, with a little gentle post-processing using WxToImg to produce the ‘false colour’ images.  I used the ‘gpredict’ program to track and display the various satellites passing overhead and on the day it went down quite well.

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Everybody Loves Wednesday Nights @ The Club Rooms!

Don’t think that because the Amateur TV experimenters group is having a break while waiting for a new studio to become available that things on a Wednesday night have slowed down. This past Wednesday saw a cracking display of activity at the club rooms.

Every Wednesday evening the REAST clubrooms are open for members to attend, being up their projects to work on, or just sit down and have a bit of chat about the week with friends.

Tom VK7NTK was busy tuning an analogue filter to boost frequencies in the 1000Hz – 1500Hz range. It is hoped that this board will help improve the attenuation issues being seen with the raspberry pi based IRLP node that is a whole tale in itself!

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LCA2017 Open Radio Mini Conference

LCA Casino by @taniawalker

Last Monday members of REAST were proud to be able to take part in and present at the Linux Conference Australia 2017 as part of the Open Radio Mini Conference at Wrest Point Convention Centre.

Linux Conference Australia is a weeklong event, with a number of 1 day mini conferences held over the first days of the event followed by 3 days of main event and selected presentations.

There were a number of fantastic talks at the event on Satellites, Getting into Amateur Radio, HPSDR, 10GHZ EME, Hamlib along with a panel discussion. One of the fantastic things about LCA was that all the sessions have been recorded and placed on Youtube, with the links below:

 

All Sessions were well attended with anywhere between 30 and 50+ people sitting in the room listening to the presentations

Also at the conference was Steve Conklin AI4QR who presented as part of the main conference on the Phase 4 Geosynchronous Satellite Efforts in progress with AMSAT. This was a fascinating presentation and can be found by following this link.

Special thanks to Scott VK7LXX who was the organiser of the successful mini conference. Scott was also one of the core conference volunteers being responsible for mini conference liaison and maintaining the Linux.conf.au Website. Well done Scott!

 

AMSAT-VK National Net December 2016

The last AMSAT-VK national radio net was held tonight with VK7LXX and VK7BEN participating via Echolink. They were greeted by regulars Judy VK2TJU, Bob VK2AOR and George VK2WEL.

Tonight’s net saw discussion about the new Chinese satellite being launched on December 26 with the designation BY70-1. The 2U Cubesat will have a V/U FM transponder with an uplink frequency of 145.920 MHz and a downlink frequency of 436.200 MHz. Further information can be found on the AMSAT NA Website.

Additional activity discussion centred around SO-50 operation and techniques to access it. Scott filled the group in with his progress in making a SatNOG base station and Ben discussing the recent attempts being made at the REAST clubrooms by Justin VK7TW and Danny VK7HDM.

Thanks to Judy for hosting the national net, and we will do it all again in February 2017!