SOTA closer for VK7

I don’t always catch the week-end broadcasts, but I was mighty happy that I did this week-end. Here’s the start of the VK7 news:

I am pleased to let you know that the mapping of candidate peaks for VK7 has been completed and checked and the listing has been submitted to the SOTA organisation in the United Kingdom for final checking and uploading into the SOTA watch database.

I will let you know once the final checking has been completed and summit logging can commence.

I can’t wait!! It’s been a big effort by the team mapping all the summits and I for one am very thankful for their efforts.

I’ve been keen on SOTA since I saw the initial mention of SOTA Australia in ‘Amateur Radio’ magazine way back after I got my license – and hence I’ve owned my FT-817ND ever since. It then seemed to stagnate for many years, but suddenly out of the blue it took off with a vengeance, and not long after I left VK1 (for VK7)… VK1 went live. I couldn’t believe it.

But soon, I’ll be able to join in on the action down here. And hopefully, I might even be able to sort out my interference issues at my QTH and do a bit of spotting – but that’s still a work in progress… more soon.


Interference Continues

Example interference around 14.070 Mhz

Example interference around 14.070 MHz

I’m still looking into my interference issue and have found a few more tidbits about it. One is that it seems to be seriously broadband in that I tracked it from about 7.9MHz to 23.0MHz repeating about every 5.04kHz. (Keeping in mind that my antenna is tuned for the 20m band so at those ranges any reception is pretty weak.)

Further, I started to wonder if it was my radio, so I swapped from my FT-817 to my IC-718 and the issue was still there.


The interference differs too. Around the main frequency of my antenna I see squiggly lines on the waterfall (as above), however once I get further away I see what I primarily consider straight lines as seen on the right.

Anyway, to visually see things a bit more I also put together two time lapse videos of the last two 24 hour periods. The first being on the Yaesu and the second on the Icom. Unfortunately to show them here on WordPress, they’d like me to upgrade my account – so I’ll have to get back to you as to how I’ll share them.

Another thing I tried, tonight I pulled everything out and now only have the Icom connected directly to the antenna via the wall socket and have it running on a battery. But still the interference persists.

I’ve also done things like disconnected the antenna – waterfall went quiet as expected; turned off the radio – waterfall went quiet as expected.

But the waterfall capture is starting to show me is two things:

  1. There seems to be good digital activity on 20m an hour each side of 1300hrs each day – hopefully I can enjoy it at some point; and
  2. A pattern might be emerging – at least I think I see the interference start around 7pm and stop around 10:30pm – but need many more days yet (and there’s also a possible morning start and stop too. And that makes me further think it’s a person doing something and maybe in the form of heating.

Anyway, hopefully a bit more monitoring might reveal some patterns as I’m kind of out of ideas to try – I’m fairly comfortable to say the source is not from my block.

20m Interference – Starts and Stops

So I just sat and watched the waterfall for a bit in Spectrum Lab on 20m (14.070MHz). To my surprise I observed the noise suddenly start and stop (see below).

That’s making me think it’s more likely some kind of electronic device, and just maybe something like a reverse cycle heater (or heat pump as they seem to call them in VK7). Anyway, I’ve now setup spectran to go nice and slow and do 15 minutes captures – so I’ll see what that yields.

But still, if anyone has any ideas, please drop me a comment. 🙂

Maidenhead Converter Library

Click to github project

Click to github project

I’ve been putting together a little groovy/java library for doing maidenhead conversions – mh-converter. It’s pretty early on at the moment, but is basically documented, has a test suite and is known to work. So effectively I’ve put it out there as a 0.1 type release. As well as providing a JAR for use in other projects, the JAR also provides a command line interface.

Anyway, if you want to have a play then feel free to grab a copy from github at:

You can then build yourself (as long as you have a JDK installed) and do with it as you like.

I will be making further changes (maybe) as I’m yet to actually use it as the intended library I was after for something else I’m working on. So we’ll just see where that takes it.

Attempt to setup for 20m – interference

Example of interference on 20m - 14070

Example of interference on 20m – 14.070 MHz

My long term goal here is to have an inverted V for 40m. However the other week I was looking at my 10m vertical in the garage and started wondering what I could throw up in the short term for HF. It then dawned on me that between the eave support for my 2m/70cm antenna and a pole in my back yard for an old arbour I’m pulling down, there’d be just enough space for a 20m dipole!

So last week-end I finally got a basic dipole up, tuned it and the SWR was looking good! I attempted some WSPR and I was happily receiving stations from America and Europe (albeit, my shack computer currently has no network connection – so I was unable to post spots). In return, I could see I was also making the same distance.

However shortly after that I realised this was causing TVI. I thought this was surprising considering it was low power and at 20m, however whenever I transmitted I immediately trigged a ‘No or weak signal’ message on my TV.

Example of interference on 20m - 14070

Example of interference on 20m – 14070

Easy fixed, I wont transmit until the week-end (when I’ve time to investigate and address) and will just attempt to receive some SSTV. But this turned into a rather mediocre result and led me to look closer at what I was receiving. I then realised there was little point fixing the TVI issue as I was going to have trouble even receiving!! The image on the right is what I saw (which is also reflected in the S meter sitting up at a solid 9).

The image was taken at 14.070 MHz as one of the main things that attracted me to 20m was the hope of lots of digital work – and that’s focused between 14.070 and 14.090. But up at 14.230 (the SSTV calling frequency) the image was similar albeit the lines are more straight/constant.

Anyway, I did the normal thing and turned off the power to my house and ran on battery supplies. But the issue persisted – indeed, it didn’t seem to change at all. So I guess there’s some localised interference, but I’m not entirely sure what this pattern might be caused by or indeed what my next choices might be. I’m kind of just taking it as a sign that 20m  is out… But that said, if you recognise this pattern (or have suggestions) please jump on in and leave a comment.

10mComparisonAs a comparison, I thought I’d see if I could tune the dipole up on 10m an see what that looked like. The image to the left shows the result. Further to this though, I was able to happily send and receive WSPR to America as well as the reception of a couple of SSTV images also from America.

So whether that means I cut the thing down to size for 10m and just go with that until I get my proper 40m setup done… I don’t know. Anyway, it’s the end of the week-end so I guess I’ll just have to ponder it a bit.