Power output: Somewhere between 150mW and 200mW.
Coax: 30m RG213
Aerial: Broadband Hexbeam at 35ft AGL beaming pointing west
Best DX: KB9AMG at 6,378 km (3,963 miles) at 31,890 km/Watt
Two hours of 20m WSPR on a Sunday evening
The twenty two stations who heard me during two hours of WSPR on a Sunday evening
Power output: Somewhere between 150mW and 200mW.
Coax: 20m RG213
ATU: SGC Smartuner
8m 450 ohm open feeder
Approx 65ft doublet, sloping E-W, 30ft AGL at the east end, 20ft at the west end
Best DX: OE6WSF at 1,185 km (736 miles) at 5,925 km/Watt
One hour of 30m WSPR on a Sunday afternoon
The fifteen stations who heard me during one hour of 30m WSPR on a Sunday afternoon
I’ve written a fair bit about WSPR in the past and posted reports of where my signal has been heard using just five watts output. I’ve also written about QRSS including details of the transmitters I’ve built and shown reports of where I’ve been captured.
A few weeks ago I heard about a new QRSS kit from Hans Summers, the ‘Ultimate 2‘ kit which includes DDS frequency controlled output – A much better way of doing it than trying to tweak a trimmer for frequency and adjust a gimmick capacitor for bandwidth. I ordered one of these kits along with a GPS module and the kit arrived late last week.
I assembled the kit on Friday afternoon last week and it went together really well. There’s not much to do, just a handfull of capacitors, a couple of resistors, two transistors and one coil to wind. The DDS module comes pre-assembled and that just left the bandpass filter which is three coils and four capacitors.
‘Ultimate 2′ QRSS/WSPR tranmitter, filter and DDS module by Hans Summers
I ordered it with a complete set of filters, the first one I built was 20m so I put it on the air straight away using WSPR on that band. I left it running for nearly 24 hours and by using the WSPRnet site, I was able to see where my signal had been received.
Map of stations where my 20m 200mW WSPR signal was received
Over that (approximately) 24 hour period my signal had been received nearly 500 times by 62 different stations with the furthest away being WA7KGX at just over 7,900 km (4,900 miles) which I think is pretty good for just 200mW output. Since then I’ve been spotted by K6PZB at a distance of 8,609 km (5,349 miles).
I’ve not built the transmitter into an enclosure yet, it’s just resting on top of my rotator control box.
‘Ultimate 2′ transmitter, transmitting on 20m
And yes, that is a 5p coin glued to the DDS module acting as a heatsink!
I’m doing some 30m QRSS tests now. QRSS isn’t so instantly gratifying as WSPR but it’s another good propagation testing mode so I’m keen to see how well it works. I’m currently seeing myself on the LA5GOA grabber in Norway so I know it’s at least getting that far and that’s just on my random length doublet through an SGC smartuner.
G6NHU on the LA5GOA grabber
A few months ago I heard about a new data mode from Joe Taylor, K1JT called JT9. I looked into it and even tried calling CQ a few times on 40m using it but with no replies and no sign of any activity. I quickly gave it up as a bad job but before long I started seeing twitter posts and blog entries about this new mode. It seems that when I first looked at it, the only way to get a QSO was by sked because it was so new and there were so few people using it.
JT9 has some similarities with JT65A – It’s designed for LF and HF work and will decode very weak signals. However JT9 in the most common mode will decode signals 2dB weaker than JT65 and it uses just 15.6Hz bandwidth which is less than 10% of the bandwidth that JT65 uses. JT65 users will appreciate that this is very good as it can often be difficult to find a clear spot to operate due to the popularity of this new mode.
JT9 has five different modes, the fastest allowing a QSO to be completed in six minutes, the same as JT65 and the slowest taking up to 30 minutes per transmission period (up to three hours for a single QSO) and using just 0.4Hz bandwidth. Most QSOs will be made using the fastest mode.
I tried JT9 again just over a week ago and I was making QSOs straight away – In one session I counted over 12 stations all showing in the waterfall at the same time so there’s a lot more activity than when I first started.
It’s well documented in my blog that my first ever QSO to VK land was using JT65 on 40m so I was very pleased to work VK7BO (same operator, different callsign) on 20m JT9 on just my fifth day of using the mode with nice big signals each way. With JT65 I normally ran 10-20 watts but I’m keeping my power down to 5w for all JT9 QSOs.
Working VK7BO on 20m JT9
The JT9 mode is implemented in the WSJT-X software which can be downloaded from here. I thoroughly recommend you have a good read of the user guide before you start using it as everything you need to know is in that guide. It’s very similar in operation to JT65 as can be seen above.
Looking back over my records for the past three years, April is always one of the quieter months of the year and it’s no exception in 2013. I was hoping for a few more QSOs over the months but over 700 is still a good total.
In April I worked five new entities, these were Cocos (Keeling) Islands, Tuvalu, Mozambique, Ogasawara and Tokelau Islands. Sadly I missed out on the 5W0M DXpedition because although they were a good signal, I just couldn’t get through the pileup.
QSOs made: 706
DXCC entities worked: 95
New DXCC entities worked: 5
Total DXCC worked: 253
Total DXCC confirmed using LoTW: 231
Total DXCC confirmed using LoTW/QSL cards: 245
Today has been a day for doing things. I’ve only had one QSO on the wireless but I’ve spent a lot of time doing radio related stuff.
I started off this morning by getting all the bits together for my set of 5B4AGN bandpass filters. My first attempt to wind one of the toroids was a disaster and resulted in my taking it all off and starting again but I was pleased with the second one I did.
7 turns, quadrifilar wound toroid
It didn’t take too long before I had a complete set of toroids wound for the 40m filter.
All the toroids wound for the 40m 5B4AGN bandpass filter
I fitted two of them and the capacitors onto the board ready for the first stage of the alignment procedure.
The 40m filter board ready for the first alignment stage
At this point I realised that I don’t have everything I need to start aligning the filter so everything went back into the boxes and has all been stashed on my shelf.
The next thing I did today was to do some aerial work. I wrote a while ago that I’d refitted my smartuner and increased the size of my delta loop but unfortunately it wasn’t working very well. I was suffering badly with RF feedback into the tuner and so it needed changing. At the end of March I removed the loop and replaced it with a random length doublet, running from the top of my mast to the pole at the end of the garden with 450 ohm ladderline feeder going back to the tuner. This worked OK but because the ladderline was close to my mast, when the wind blew, the feeder touched the mast and the tuner retuned.
I went to B&Q and picked up a two plumbing T-pieces and a length of pipe. I cut a length of pipe around a foot long and fitted the T-pieces to each end. One T-piece had a slit cut through the side and the other one was completely cut in half. I fixed this end to my mast with one jubilee clip (I’ll put a second one on when I next lower the mast) and ran the feeder through the other end, thus supporting it a distance away from the mast and secured so that it won’t move when the wind blows. It’s a poor picture because I took it from the ground but hopefully you can see how it’s been done.
Homebrew standoff to keep the open feeder away from my Alimast
Finally, I made up the clamps for the 12m Spiderpole I recently bought in preparation for the DXpedition later this year with the Martello Tower Group to Herm (EU-114). This involved opening 11 jubilee clips, cutting and fitting rubber strips and heatshrink and using a heat gun to fix it all in place. I then put the Spiderpole up in the garden to test it.
Clamp set for my 12m Spiderpole
All in all, it’s been a good day. I didn’t hurt my fingers too much winding the coils, I didn’t fall off the ladder while I was fixing the bracket to my mast and I only burnt myself a couple of times while using the heat gun on the clamps and I only cut myself once while fitting the clamps to the pole!
I created the Martello Tower Group Twitter account almost exactly three years ago on the 18th April 2010. The plan was to use that account alongside my existing account and post information about the group, things we were doing and other group related updates.
It’s grown to more than that though and now the account really is mine. I still post things relating to the Martello Tower Group but most of the tweets are unrelated to the group. I’ve built up a nice list of radio related followers and I tend to only follow people back who are involved with amateur radio.
It’s been mentioned a couple of times over the last two years or so that perhaps the account would be better if it had my name specifically on it rather than the group and I think it’s now time to make that change.
I’ve already changed the picture on the account from the group aerials to my own. In the next few days I’ll change the name from Martello Tower Group and then after a short while, I’ll change the username. I will tweet updates before I make each change to give followers notification.
Note – I am talking about the Martello Tower Group account (@G0PKT), not the account linked from this blog (@QSO365) which will remain unchanged and continue to tweet updates when I make new posts here.
