Wednesday, November 11, 2015

Another visit to the Kurrajong Radio Museum

I visited the fabulous Kurrajong Radio Museum once in the past with my partner in tow and while she found it "mildly amusing" I thought it was time for a repeat visit.

I contacted Ian via the email on the site to organise the visit in advance and he was most gracious with his time and knowledge.

With Mal, VK2BMS and Robert VK2ZNZ in tow we met up with Jules, VK2EXT for a grand tour. Some photos from the day:

Saturday, October 17, 2015

SDRPlay receiver with SDR Console

Since eliminating the annoying interference I was suffering, I've returned to the pleasure of tuning around on HF. A while back I bought the US$150 SDRPlay receiver. Getting it going with some of the common software is a bit of a trial due to the proprietary driver that's needed.

SDR Console is a very nice SDR receiver program that works out of the box with SDR Play. (Be careful on their site, they accept ads that portray themselves as bogus "download" buttons).

SDRPlay is more expensive than the RTL-SDR TV dongles but it's really worth it. They have a 12 bit A/D and capture a much larger part of the spectrum so it's easier to see the whole band and find stations.

Here's what AM shortwave stations look like.

And here's 40m LSB on an active Saturday afternoon.

A tiny snippet of video shows how it looks when running.

I'm running this on a Lenovo ThinkPad X201 with Windows 10. It's a Core i5 processor at 2.4GHz with 4GB of RAM. The software reports only about 4% CPU so there's plenty of headroom. You would struggle to run this on a cheap netbook.

One tip - there are keyboard commands for moving the IF and tuning up and down but they're disabled by default. There's a setting and then you can use PageUp and PageDown to move IF and arrow up and down to tune. Fine tuning is by holding the Control key.

Sunday, October 04, 2015

Locating the source of local HF interference

In recent weeks my reception of HF radio, particularly on 40m (7MHz band), has been marred by nasty broad band interference. I had thought it was from a neighbour's TV.

Using a portable shortwave radio with a strength meter, I walked around the house trying to find the cause but it just seemed to be strong everywhere that mains wiring went.

After shutting down all computers I turned off the house main switch and the interference was gone.

By plugging things back in, one by one, I found the culprit.

Many of us suffer HF interference and the more computers and appliances we have the more likely it is, but this experience shows that it can be located and removed.

Saturday, October 03, 2015

Sydney meetup with Peter VK3YE and Stephen VK2BLQ

A rare pleasure today to meet up with home brew hero Peter, VK3YE, who was visiting Sydney.

Stephen, VK2BLQ and I caught up for a chat and Stephen brought along a phasing receiver for Peter to inspect.

We had an entertaining discussion on many topics and I hope one day to get Peter along to an ARNSW Home Brew Group meeting for some sort of chat.

Thanks Peter for all your great work to help ham radio and home brew on the web sitevideos and all the articles in various magazines - we really appreciate your efforts and encouragement.


Peter mentioned that he was close to publishing a book about QRP operation and that book is now available on Amazon. Minimum QRP is well worth a read.

Peter shares his considerable practical experience of ham radio in an easy to read and informative book. It covers equipment (including commercial and home brew), antennas, bands, propagation, modes and operating procedures that give the reader valuable tips on how to enjoy success in the challenging art of low power operation. The focus on QRP is, of course, valuable for operators working at all power levels.

Peter has always been generous with his contribution to the hobby of amateur radio and this book adds to the information available to newcomers. I look forward to more from VK3YE in the future.

Great cover by the way.

Tuesday, September 29, 2015

Everything looks better from a drone

Last weekend I was invited to film a friend's property from my drone. I'm a pretty poor flyer but the result is nice. It was a fabulous day for flying.

Wednesday, September 23, 2015

A weekend away at the faded Hydro Majestic

Pip and I took advantage of a "Spring Escape" in a "Heritage room" at the Hydro Majestic in Sydney's Blue Mountains.

Not being from Sydney, I don't recall the glory days of old but do remember years of passing the place while it was being refurbished.

At $167 per night, the "Heritage" rooms turn out to be a nod to our convict heritage. As one reviewer on TripAdvisor writes, "there's hardly enough room to change your mind". We rang reception and paid considerably more to upgrade to a more spacious room with a nice view of the car park.

The staff were nice and presumably we're not the first to react this way to a room even they refer to as "compact".

There's not much to do at the place but compete for a chair that gives a glimpse of the pleasant view.

Some cushions would be a nice addition. The free Wifi is very slow but functional.

Drop in for a glass of wine on the way to an AirBNB but I don't recommend staying here. Staff were nice though and General Manager Ralf B is amusingly responsive on review sites.

Saturday, September 05, 2015

ozQRP MDT Double Sideband transceiver kit review

I learned of the Minimalist Double Sideband Transceiver (MDT) kit from the video review by VK3YE and thought it might be a fun project.

The price is $75 but it includes everything you need except a microphone. The parts are well packed and clearly marked. The circuit board is excellent quality and all parts fitted well.

The manual is very clear and I found construction quite smooth.

The only confusion I experienced was figuring out which way around the BD139 transistors go in the board (the label side is closest to the edge of the board).

I spent a lazy Saturday on and off doing the build in short bursts. Late in the afternoon I was tuning around and the direct conversion receiver sounds excellent. The carrier nulling was easy and from what I can hear off air transmit audio sounds good. So far no one has responded to my CQ calls for a report but I'll get back to you when that milestone is passed.

It's a great kit for a constructor with at least a little experience. A very compact rig that could be good to take on a hike.

Update: First contact with Mal, VK2BMS who said the audio sounds good although a little basey - which is probably more due to the microphone than anything. Mid dial was 7.10604 so that's good to know.

With the second varicap link open mine covers 7.090 - 7.127MHz. Tuning is quite sensitive so I wouldn't want more range without a multi-turn pot so I think this is a good range.

Just had another contact with Ian, VK3AXH in Ballarat who gave me a 5 and 3. He's running 200W and I'm running about 2W DSB. He commented that the rig is "doing a remarkable job". I do find that after switch on it drifts a bit but it's a pleasure to use.