AutoCAD files for Ultimate 3

I’ve used AutoCAD for a while (because I had a work licence) but since being promoted I didn’t need CAD software…boooo (I also had an inventor licence but that wasn’t used as much). Anyway, back to the point.

U3 small

I made a couple of front and rear panels for the QRPLabs ultimate 3 WSPR transmitter and thought that someone else might like to make one. Well if you do the dxf files are below. You can modify them easily in Draftsight (A free 2D bit of CAD software) that accepts AutoCAD files. The file shows the parts embedded on a sheet that can be used for laser cutting and your local FabLab or similar.

Anyway enjoy

AutoCAD Files


I’ve had a little play about whilst avoiding the household viewing of ‘Strictly come dancing’ aka ‘celebrity showing off’ with the APRS maps you can embed through

I’ve added a little map to the site here

Just a bit of fun but I do like APRS. Great for the fells.

Trouble is it seems to default to Helsinki regardless of the lat / long you put in the script

Progress on the node

There’s been a bit of positive progress on the node at g7kse headquarters.

Mucking about with Echolink software proved a time consuming affair. This and that connected but not playing with each other and some absolutely horrendous noises coming out of all sort places and some shocking audio means that there is a good chance that isolation is needed. So a couple of transformers have been ordered.

Once the software is sorted on windows and I have all the hardware playing nicely I’ll move onto the RPi. I have a lot less experience with linux and image that hours will be consumed (lost) compiling and fulfilling dependencies and other joyous things that you get just installing stuff on linux. The benefits way outweigh the drawbacks. A headless and simple set up is key to a lightweight setup.

Once the odds and sods have arrived I hope to get something up and running reasonably quickly. Daniel, M6ENL and I had a quick go with it last night and it worked well enough for us it was nowhere near robust enough to be let out in the wild.

Onwards and upwards…….

p.s. The GPS on the U3 died as well so there’s that to fix too. Bugger.


Today I received a very nice email from Ofcom. It was my NoV for my echolink node.


Whilst I won’t be able to get it up and running this weekend because we have guests I hope to have everything up, running and ready for use early next week.

There is a restriction of 1.6w TX output using the 1/2w dipole (vertically polarised) but I’m keen to get the thing up and running. Eventually It’ll all be on the RPi but for now it might be quicker to install onto one of the old netbooks and to use that as a way of optimising audio and tx settings before going headless. There are a few restrictions on its use but they are perfectly sensible and being able to be unattended is a real bonus.

Exciting times. Here’s hoping it’ll get used by more than just me.

Echolink Node?

Over here in G (or M or 2) land echolink nodes need to have permissions from the grown ups. So I’ve sought permission from Ofcom, with the help of the RSGB. I applied for an MB7 node, which means it is can be unattended. In order to do this I needed a minimum of 4 people who are key holders so the node can be shut down quickly. Sounds reasonable? Sounds a bit British to me. Belt and braces and some more belts just for luck.

The node will hopefully be on 2m and I have been told that if it gets granted then I could expect around 2w ERP. I don’t want to sound selfish but I have only heard 2m simplex used in this area for the local net and once in a blue moon Dent gets activated by a SOTA or WOTA chap(ess). VHF in general is scarcely used and its a shame.  UKAC evenings and the normally quiet repeaters with their occasional skeds excepting mean that both 2m and 70cms are dead.

What can be done about it?

Making it appealing to use, perhaps? A bit of activity always helps.

Internet link may give some users an opportunity not only with existing amateurs but could make it appealing to those on the periphery of the hobby. Makers for example.

Anyway, let the waiting begin and we’ll see where we get to with Ofcom

A summer outside

During the week I took a trip with 3 other members of the Workington Amateur Radio Club ( to the Furness Amateur Radio Club. A short hours drive away courtesy of Barry, G0RZI. There was a 2 pronged attack on their club, firstly Glyn M0UXH gave the low legendary power supplies presentation (legendary as it has the dubious honour of being the most postponed talk at the club) and my chat about what we do as a club with a hot soldering iron.

What struck me is what might be a common theme for clubs, not just with amateur radio, but the fact that we can all get a bit stale. What also struck me was that we have a similar demographic. Some really talented, clever people who can design and build stuff without batting an eyelid. Some (and I include myself in this) enthusiastic but short on skills and experience, and those that just like to use stuff.

I shared our experiences with building the Radio Kits digital power and SWR meter, the Ultimate 3 kit from Hans Summers and my experiences with Arduino’s. The latter included the great stuff being done by K3NG (Radio Artisan bloke) and those that support his work in producing kits and PCB’s. I was pleased to see that I wasn’t the only one who has an interest in the ‘Maker’ fraternity and that tinkering is alive and well in Cumbria.

In between all this mucking about I do occasionally operate. But owing the excellent summer we’ve had I prefer to be outside, in fact I should be out on my MTB today but I’ve got a 10k race on Tuesday and don’t fancy doing it after an ‘off’. This weekend is the Cumbria Raynet support to the SBU 35 trail race from Bassenthwaite to St Bees over Honister. First one home in about 5hrs 30mins and the last around 12 hours. A long day for us but nothing compared to the competitors. Maybe I’ll do it next year. Maybe I’ll make use of Ennerdale Brewery instead, the summer ale was great.

After that it is most definitely heading for Autumn and time to bring out the mic, soldering iron and broken PCB’s. Looking forward to it already!

All ok?

Website moved to a new server…seems all ok to me. This new server will give me more space and flexibilty as well as being far faster than the previous one.

update: A couple of issues need ironing out but these won’t be done for a bit. But things are back on the air at least.

Category: Web

Solder fumes

Mention Health and safety and its likely you think of some Muppet decides that children need a suit of armour to play conkers (for those not lucky enough to have tried to make a horse chestnut seed the hardest material known to man, have a look here). Back to the point. I’m talking about looking after yourself in your hobby.

Ham radio has some pretty high hazard activities. High voltages, antenna’s on towers, climbing on roofs etc. Recently I’ve been soldering a bit more. Whilst its not likely to be particularly harmful to occasionally sniff in some fumes its probably not going to do me much good either. So I might benefit from a solder fume extractor.

I understand that the technical terms (and we all love a technical term) is local exhaust ventilation or LEV. Still doesn’t sound too complex and thankfully it doesn’t need to be. A fan that sucks and a filter is pretty much all you need, it seems. So do I really need an industrial scale extractor? probably not. So as an experiment I’ve bought a £5 extractor from eBay.

Its an mdf laser cut body with a 12v (computer?) fan. It takes 5 minutes assemble and may or may not need some PVA to hold it all together. I say might as mine was a good tight fit so probably won’t need it in the short term but as it gets bashed about on the workbench it might need some help to stay together.

The extractor is basic (what do you expect for £5) and didn’t come with any filter media. So a suitably sized filter will be needed. Perhaps the same activated carbon you get for cooker hoods would suffice, will need to be sourced. I dare say just sucking it from one place to blow to another isn’t really helping matters.

I could measure flow, compare against standards, determine filter abatement. I say could, because clearly this hasn’t been designed with that in mind and how would that really help? The video below shows you how effective it actually is.

So the conclusion. The hazard associated with occasional solder fumes is probably quite low and the risk is also probably quite low. But a simple device, like this, has the opportunity to remove the fumes from the workbench and at the very least stop them going in your eyes. That can’t be bad.

Here it is in action. Distance between tip and fan is approximately 10cm.

p.s. If you’re really lucky you can hear my daughter homebrewing in the background (what she is homebrewing is anyone’s guess)

Maidenhead Locators

Locators, or as us Brits call them, Maidenhead locators. Named after a town in Berkshire that isn’t close to the meridian but held a meeting by a bunch of VHF chaps in the early 80’s. In fact the now de facto method for looking something up (Google & Wikipedia) give us:

‘The Maidenhead Locator System is a geographic co-ordinate system used by amateur radio operators. Dr. John Morris, G4ANB, originally devised the system, and a group of VHF managers, meeting in Maidenhead, England in 1980, adopted it. The Maidenhead Locator System replaces the older QRA locator system with one that is usable outside Europe.[1]

Maidenhead locators are also commonly referred to as QTH Locator, grid locators or grid squares, despite having a non-square shape on any non-equirectangular cartographic projection. Use of the terms QTH locator and QRA locator was initially discouraged, as it caused confusion with the older QRA locator system. The only abbreviation recommended to indicate a Maidenhead reference in Morse code and radio teleprinter transmission was “LOC”, as in “LOC KN28LH”’

But more to the point how do you calculate one? Easy if you know Perl (apparently – thanks again Wikipedia)

#!/usr/bin/perl -w
# (c) 2012 Chris Ruvolo.  Licensed under a 2-clause BSD license.
if($#ARGV < 1){
  printf("Usage: $0 <lat> <long>n");
my $lat = $ARGV[0];
my $lon = $ARGV[1];
my $grid = "";
$lon = $lon + 180;
$lat = $lat + 90;
$grid .= chr(ord('A') + int($lon / 20));
$grid .= chr(ord('A') + int($lat / 10));
$grid .= chr(ord('0') + int(($lon % 20)/2));
$grid .= chr(ord('0') + int(($lat % 10)/1));
$grid .= chr(ord('a') + int(($lon - (int($lon/2)*2)) / (5/60)));
$grid .= chr(ord('a') + int(($lat - (int($lat/1)*1)) / (2.5/60)));
print "$gridn";

But what happens if its all Dutch to you (It is to me)?

Well I put together a simple spread sheet that does the calculation. Its nothing special but deciphering what several different people have put into explanations that include adding your birthday, taking away your dogs maiden name and that kind of thing. Hopefully it’ll help you understand where those numbers come from and how to calculate them. So help yourself and if it doesn’t work then fix it and share it ( I tested it with 3 locators and lats / longs and it seemed to work). I also learnt a few more things about Excel so its all handy.

Here it is then

QRP Labs Ultimate 3

Some months ago I was planning an afternoon at our local Fab Lab, partly to help raise their profile and partly to introduce some club members to the easy to use laser cutting services they have. We designed an profiled a case for the QRP Labs Ultimate 3 WSPR transmitter.

It occurred to me that I haven’t really shared the experience having been enjoying myself at the 24 du Mans race, celebrating my parents 50th wedding anniversary and having a birthday. None the less, its time for a catch up.

The U3 is a fairly simple build, in its basic form takes about and hour and a half to build and test. Start adding the various extras like a switchable band pass filter (for 5 bands!) and a gps unit and the time to build, well builds up. The kit isn’t complex and doesn’t use smd’s (although I’ve never understood the fear of them – whilst my eyes are still ok) and there’s only 4 coils to wind for the basic version.

The biggest issue was how to box it up. After trying various configurations we settled on a very simple front and back panel design, Others, like the desktop version or ones with castellated fixings either looked a bit cheesy or were hard to put together and prone to breaking. A simple 2d CAD sketch is loaded onto the machine, plonk in the materials and you’re away. It couldn’t be simpler. Anyway here’s the semi finished product. I need to do something about the spacers as they look awful but its nearly there.


U3 small