AmateurRadio.com

Tuesday night is RSGB UKAC contest night, this week on 432MHz. Following the frustrations of the weekend I spent a therapeutic Monday evening cutting various lengths of RG213 and fitting N-Type connectors.

I have now got a coax run through the wall into the shack, with another to follow soon. To facilitate 'switching' between multiple aerials I have fitted each aerial with a length of coax running down the pole, terminating in an in-line N-type socket near the base. It is a simple case of connecting the appropriate shack coax, fitted with a n-type plug, to the appropriate socket.

To keep everything water and weatherproof I have opted for a DRi-BOX. These are inexpensive plastic boxes sold as waterproof housings for outdoor electrical installations such as garden or Christmas lights.




The lid has a silicon seal and there are a number of cable entry points with a flexible seal. When the lid is firmly clamped securely in place the box is effectivly watertight.


It is a bit of a fiddle with the thick RG213 but it seems to work well. There was a vicious thunderstorm and downpour yesterday afternoon and the Dribox lived up to its claims after sitting in a few inches of water.

Still awaiting the X-50 collinear on the top!

The pole now has the 2M Yagi and the 70cm 7-element ZL-Special fitted. The 70cm aerial is far from optimal but I was looking forward to giving a go with some decent coax.

Tuning around prior to the start of the contest and the band seemed quiet, hearing just a strong local operator. The contest start time passed and I was met with a wall of static only hearing the occasional very weak signal. I tried unplugging and reconnecting plugs, new patch lead, took the VSWR/Power meter out with no effect after 20 minutes I gave up. I decided something was obviously wrong with my new installation at the top of the pole.

I went back into the house where the wife was watching some dreadful house/diy/makeover program on TV which I could only manage for about 15 minutes. Grumpily I went upstairs and fired up the FUNCube Dongle and twitter and realised I'd forgotten and completely missed the first pass of the newly launched UKube-1, unlike some lucky ones. Idly I tuned to 70cm using the discone in the loft and could see a waterfall of signals! Including that local operator with a lot of splatter considering he was running just 10W


Going back into the shack and things had improved, so perhaps it wasn't my setup! After missing nearly a hour I searched and pounced again, just making 14 contacts but achieved my highest score so far for a 432MHz UKAC contest, still operating as M6GTG in the low power section.



Various operators have commented on the weird/poor/flat conditions last night, so perhaps I shouldn't have been so dismissive of my ability to put up a decent antenna!
Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

Part 1 of 2

I’m traveling this week with a DHAP and the Icom ID-51A dual-band handheld. This combination of hardware permits me to stay connected with my friends on the D-STAR network from wherever I happen to roam – no local digital repeater required. The DHAP is a custom-built enclosure and battery supply for a Raspberry Pi and DV Access Point – a DVAP.

If all this sounds like too much alphabet soup (it is!) let’s first break it down in pieces.

The DVAP is a small USB powered D-STAR transceiver that runs about 10mW of power on UHF. VHF is also available. It’s manufactured by Internet Labs. The concept here is that you plug the DVAP into a USB port on your Windows, Mac or Linux computer, running the proper software and connected to the Internet, and it looks a lot like a D-STAR repeater to your radio — albeit a micro-repeater with only about 100 yards of coverage.

With this arrangement, a user can connect to other repeaters and reflectors on the network. While it’s an effective solution, it’s not elegant or efficient to keep a desktop or laptop computer running all the time just to maintain that connection.

Enter the Raspberry Pi, a single board computer that’s smaller than a pack of cigarettes, costs $35, supports networking, and runs Linux. It didn’t take long for users to see the advantages of this arrangement over the desktop PC and the rapid migration was underway.

You can put all this together for the price of the DVAP and another $50-100 for a Raspberry Pi, memory, associated cables, power brick, and all that jazz. It will work perfectly well setting on your desk or workbench like that, but if you want to take it outside with you, an enclosure to house and organize it all is a really good idea.

Which gets us to the DHAP. Manufactured by Hardened Power Systems, this contraption is a robust enclosure for the DVAP and the Pi that conveniently brings all of the on-board connections out to the front and back panels. NiMH batteries run the show for several hours between charges while a front panel display shows the battery level.

It’s not waterproof, and I suppose you could break it if you tried. But it is a hardened, machined case that’s slightly smaller than a football. Once it’s configured and charged, you just pick it up and carry it with you wherever you go.

Of course, it requires a network connection that can be provided from a hardwired Ethernet cable or via a Wi-Fi network. That Wi-Fi link means it can be easily tethered to your cell phone, which is how I use it on the road, when I bring it home, it automatically connects to my home Wi-Fi.

It’s the ultimate in convenience and portability for the D-STAR enthusiast though it’s not cheap. $300 [US] for the unit with a Raspberry Pi, a little less if you’re bringing your own Pi. And that doesn’t include the DVAP…

More about how I use all this on the road, and a few tips about the DHAP in the next post.

Filed under: Ham Radio Tagged: dhap, dstar, dvap, hr, icom, id51a
Jeff Davis, KE9V, is a regular contributor to AmateurRadio.com and writes from Indiana, USA.

I’m indebted to Roger, G3XBM for pointing me at the news that the VC1T expedition was heard in the UK on 144MHz by G4SWX, but unfortunately no 2 way QSO was made, despite trying for 4 hours to make a two way contact. It is also reported that a station in Ireland heard portions of the VC1T transmission.

See the news from the ARRL site

See a screenshot from G4SWX at G4CQM’s site

Tim Kirby, G4VXE, is a regular contributor to AmateurRadio.com and writes from Oxfordshire, England. Contact him at [email protected].

The UKube-1 satellite was launched this evening with the first pass due over the UK at 2014 local time.

Coincidentally, supper had finished around 2013 local time, so I sped upstairs and switched on the FT-847 with the V2000 vertical connected. The UKube-1 CW beacon on 145.840 plus minus doppler was the first target. It doesn’t transmit continuously, but I was pleased to hear it around 2018 local up on 846. Shortly after that, I heard the telemetry on 145.915 coming through at very good strength.

Congrats to the UK team responsible for the satellite!

Tim Kirby, G4VXE, is a regular contributor to AmateurRadio.com and writes from Oxfordshire, England. Contact him at [email protected].

I thought my hands and eyes were good enough to make a start on this kit, which I have only just unpacked, having had it for months. I was waiting until I was less clumsy. When built, this will make a really useful WSPR beacon.

The packing is wrong as I had asked for a GPS module, which is missing, but there is a surplus relay board in the box.  I was very careful unpacking the kit. and have left in packets those parts not yet needed. Some are anti-static.

Sadly, my eyes and hands are not really good enough: I started on the 10m LPF PCB and, frankly, this was a real struggle both for my eyes and hands. Tomorrow I shall test this with my generator and 50 ohm load.

Two people have very kindly offered their help building the kit. I fear I shall have to admit defeat and ask them to help me. This is a great pity as I was so hoping I’d be fit enough to build this. Sadly, this seems unlikely any time soon.  My stroke is taking its toll on my abilities. WSPR is OK, but I am struggling with building still.  Talking in tonight’s contest will be hard.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Like others, I enjoy learning about the early history of radio. It gives me an idea of how far the hobby and technology has come as well as inspiring the imagination.

I found a great site, MagazineArt.org, which allows the viewer to peruse many of the covers from a variety of periodicals from the early days of the wireless.

Check out some of them here:
Popular Radio
Radio Age
Radio Craft
Radio News
The Wireless Age
Shortwave Craft

Scott Hedberg, NØZB, is a regular contributor to AmateurRadio.com and writes from Kansas, USA. Contact him at [email protected].

Yet another variation on the Pixie arrived by email today from Sverre Holm in Norway who has LM386 mods to reduce BCI, provide mute and add sidetone.

See http://la3za.blogspot.no/2003/04/using-pin-7-of-lm386-to-reduce-bci-and.html .

This looks a very useful mod to this simplest of circuits. Sverre also added a much wider tuning range that helps to get contacts. Low power does not seem to be the main handicap.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.