Sunday, May 17, 2015

Download this show wins IT journalism "best audio program" award

Marc Fennell does everything on this show, producer, presenter, interviewer, editor, music mixer and talent wrangler. All credit to the new generation of tech-savvy media stars. It's a privilege to be a very small small part of the show.


Congratulations mate!

Friday, May 15, 2015

Very low cost i2c LCD interface board

Listening to the marvellous Soldersmoke podcast I learned of these serial interface boards for driving an LCD display using just two pins of an Arduino. These boards are just $1 out of China on eBay. Amazing.

With some help from Brainwagon I was soon up and running.


The little board solders nicely on to the back of standard Hitachi LCD boards.


I'm stunned that China can manufacture stuff like this for such great prices. Everything I make will have a display.

SM1000 FreeDV in a box arrived

Very excited this week when the SmartMic 1000 arrived. This is a FreeDV digital voice codec in a very nice box. It's designed so you can hold it in your hand rather like a big microphone and just talk in to it to transmit and receive digital voice.


The case has 3.5mm sockets for everything and also an RJ45 socket for a single cable connection. It's like the Signalink boxes and has a similar internal jumper system for wiring it. I followed the instructions and quickly had it working with my FT817.




The button marked "select" on the front switches between analog passthrough (so you can hear what the radio hears) and digital mode.

To test transmission, I listen off air and decode with the FreeDV app. My scatter plot looks reasonable I think:

I can hear my voice decoded so the next step is some contacts on 14.236 where I'm listening and calling.

Notes: 
  • Mic Gain control operates in reverse.
  • Select button switches between analog and digital. On power on it defaults to analog.
  • Back button isn't used.
Stephen, VK2BLQ, also has one of these and I was able to receive him on 40m, here's a snippet.



Tuesday, May 12, 2015

80m antenna, take 3

It's tough putting up a decent antenna for 80m. The sheer length involved excludes many amateurs without large blocks of land. My shack is at the back corner of the block and I've had several shots at this.

Mostly I've used an inverted V dipole hung from a large tree at the back of the block, actually in the neighbour's yard, but the legs of the dipole have to make right angle turns and run along the fences. Recently I tried a full length dipole along one side fence line - it transmitted quite well but was very poor at reception.

This week I tried an inverted L. A quarter wave length up as far as I can go in the tree and then pulled sideways and a bit down to a pole on the side fence. Early tests with Mal, VK2BMS, indicate that he's the strongest I've received him and I'm the strongest he's heard me.

An earth stake kindly donated by Robert, VK2ZNZ, provides an excellent earth (particularly with all the recent rain) and the antenna tunes up beautifully.

It may well be that it's all ground wave between our houses, although Mal is running a dipole, but we'll see in the weeks ahead how it goes.

Naturally, I'm thinking of how I can combine my interest in drones with ham radio antennas.

Flying a micro-drone with a video camera attached, here's a closer view of the tree.


Using micro-drones to inspect antennas is actually useful. Here we see the support of the top of the 80m inverted L. Just below you can see my 40m dipole's balun.


When there's not too much wind I can take the drone up quite high.



Saturday, May 09, 2015

Mount Stromlo observatory visit

For my birthday I got to do whatever I wanted and of course a visit to the Mount Stromlo observatory in Canberra was top of the list. It's a striking location and we had a big sky above.


The site was devastated in the fire storm of 2003 and the wreckage is still visible. Melted motors.


Remains of telescope buildings.




It's a striking site that seems mostly to be visited by cyclists who ride up and down the mountain.


Oddly, my daughter who has lived in Canberra for over three years had never visited.

The cafe is closed but there is a display for visitors in the old manager's house that has a nice display including some melted mobile phones from 2003.

Wednesday, April 08, 2015

Vale David Crooks

I'm so sad to mark the death of my beloved step-brother David Crooks.


A wonderful man and dear friend. Last Thursday he was looking forward to a trip to Melbourne and later in the year to shows in London. Positive to the end.

Farewell my friend. Too soon.

Friday, February 27, 2015

Built a smaller quadcopter

A new build from parts ordered from China. This time I'm using the excellent OpenPilot flight controller. Here's an early flight in the back yard.


Thanks Cat for filming.

It's basically this "kit":
http://www.banggood.com/X240-Mini-Quadcopter-With-CC3D-Flight-Controller-p-954482.html

I didn't use their supplied power distribution board as I didn't have any documentation and had one at hand.

I used a Fly Sky 6 channel remote transmitter and receiver (these are great by the way).
Also a compact 3s (cell) Lipo battery.

One frustration is that the motors could not be bolted in place with the supplied components and I had to hunt around to get 2.5mm x 6mm bolts and some nuts.

The OpenPilot CC3D software is amazing and I don't have it properly tuned just yet but it's great fun to fly around the back yard. The motors get hot and give off a satisfying burning smell after a bit of use.

Saturday, February 21, 2015

Wyong field day 2015 - Damp but entertaining


The weather wasn't great for the big feature of the Wyong field day, the car boot sale. The ARNSW Home Brew group had a great display and spent time chatting with interested visitors. Here's John VK2ASU with Mal VK2BMS:


I showed the OpenRadio SDR on the home brew table:


While I didn't buy anything there were gifts of useful components from John and Stephen which are greatly appreciated! Some things I didn't buy:



It was great to retire to the classy bar:


For some tea, Jatz biscuits and cubes of cheese.

Built a larger quadcopter

The tiny drones are great for indoors, but to carry cameras I needed something larger. A collection of parts and a 450mm frame was ordered and finally it's flying.


I'm using a Fly Sky FS T6 transmitter and receiver and a KK2.1 flight controller.


Neither the remote or controller came with the interconnecting cable so I'm using single wire jumpers until proper cables arrive. The flight controller was recommended by Terry and is great because you can test everything and tune it by using its built-in LCD display and buttons.


While I can fly this thing the PI tuning isn't right and I'm getting oscillations while hovering. Lots to learn. Lots to learn.