Monday, July 09, 2018

Van broke down

It's an old van and so far I've replaced the differential, rear bearings, battery and tyres. Yesterday I was rather lost on muddy logging roads with no mobile reception and I noticed that sometimes the van didn't start first time when I turned the key.

Today I stopped at BCF just out of Wagga Wagga and when I turned the key... nothing.

Because it's an old van I decided to join the NRMA and today I took advantage of that with their roadside assist service.

In these Hiace vans the engine is under the passenger seat. The technician seemed ready for a battery replacement but my volt meter showed me that the battery was fine. The starter motor is underneath and a rap with a hammer and it worked! The guy explained that this is a common short term fix but in the end the problem will re-occur.

I've had the starter motor replaced for $380 (with member discount) and I'm pretty happy with that. They fixed it same day but I'm staying over in a motel. Hitting the road again in the morning.

I feel very fortunate to have broken down in a town rather than up a muddy, rarely used track, with no mobile reception. A close call.

A toilet for the van

I must admit I've been hesitant about this, but touring around in a camper van wondering anxiously about where the next toilet will be found was distracting me.

As mentioned in a previous post, I've been peeing in a bottle to avoid going outside in the middle of the night. Before heading off on the current adventure, I bit the bullet and purchased a small chemical toilet for about $160.

Also purchased was the recommended flush water additive, collection chamber additive and special toilet paper that breaks down fast. I'm advised by camping expert Tim Bowden that the flush additive isn't required and that Napisan can be used in the sewerage chamber.

Currently I'm camping alone so have no qualms about using the thing in the van with the curtains drawn and door locked, not sure how I'll go with my wife on board. Some people use a popup lightweight tent to make a separate outdoor toilet.

It's great to be able to camp at free sites with no facilities such as this spot near Gundagai near the river.

While my ultimate plan is to avoid using the ensuite if possible I was kind of keen to try it just to see how the process works and how nasty it might get. After a few days, and depositing of both number 1 and 2, I looked on the WikiCamps app for the nearest "dump point".

Dump points are fairly common it turns out. Under the lid there's a giant funnel. Next to it is a tap and hose. I wore rubber gloves but found the dumping of the cassette pretty easy and clean. The additive chemical seems to be a strong perfume so there were no unfortunate smells.

After dumping I filled the cassette with water and shook it, then rinsed it out. I did this twice and all seemed reasonably clean.

We forget the magic that city sewerage systems perform. Camping out, using drop or chemical toilets is a reminder of the reality of all this.

Sunday, July 08, 2018

VK1UN's nifty FL2K filters

Ross, VK1UN, has built a nifty interface from the FL2K VGA dongle to some low pass filters for transmitting WSPR, he writes:

I’ve gone ahead and put together what I have in mind for the VGA cable with R/G/B out.

I was thinking that, if I am running output to Banana terminals for wire antennas, I would just design 75 Ohm filters to hard connect inside the little Aluminium box between the 3 RCA socket block and Bananas. See the first pic. It is going ahead smoothly despite requiring quite a bit of accurate hole drilling and hole matching with the 3 RCA socket board.I think it will be very neat.

Secondly, I have designed three Constant K 750 Ohm filters that are dual band:

60m & 40m, 30m & 20m and 17m & 12m. Whilst I have not built these all yet, I have modelled them on LTSpice and they look to have very suitable performance and all are using standard component values or a minimum combination thereof.

Here's the box showing how the VGA connector to RCA lead is used.

 30m and 20m LPF
75 Ohm, 17 and 12m
75 Ohm 60 and 40m

I’m stopping at 12m now as I am not sure of the wave from a 17m or 12m Weaver generation, but the multiples of 48K, QRG and Sample rate seem to be close.

You can contact Ross at any of the following callsigns VK1UN, VK8UN, 6O0O, T61AA, EX1UN.

Wednesday, July 04, 2018

VK1UN's VGA dongle WSPR spotted in two states

Ross, VK1UN, based in Victoria has been generating WSPR RF using the Weaver method in GNURadio and transmitting with an FL2K VGA dongle acting as a D/A. Naturally, he's using a nifty low pass filter and antenna tuner.

On 40m over night here I spotted him in New South Wales and he was also spotted in Tasmania.

Not bad for an $8 transmitter into a G5RV on a city block.

Tuesday, July 03, 2018

QRP Low pass filters with surface mount on veroboard

Ross, VK1UN, has been experimenting with generating WSPR RF using the FL2K VGA dongle. The waveform is pretty rough and of course a low pass filter is required. His solution is mechanically very neat I think. Here's a 160m low pass filter.

The design and simulation of the 160m filter. Capacitors used were 2200 plus 220 = 2420 and in the T 2200 plus 100 = 2300.

He builds on veroboard and uses PCB mount SMA connectors at each end. The tracks are cut under the surface mount inductors. Very neat.

In the end these get boxed up. Ross has modified fl2k_file to use any of the three colour outputs so he can transmit on three different bands.

Nice work!

Installing wsjt-x on Ubuntu 1804

A note for future me. Installing the latest wsjt-x on the latest Ubuntu fails. (The version in the software catalog is very old). Here's the tricks. The main issue is that the wsjt-x deb is built against libreadline6 which is no longer available. libreadline7 is there but you need to tell dpkg to ignore the request for 6.

Download wsjtx_1.9.1_amd64.deb from

If you previously tried to install wsjtx from the deb file you'll need to tidy up with:
sudo apt --fix-broken install

sudo apt install libqt5multimedia5-plugins libgfortran3 libqt5multimedia5 libqt5serialport5

sudo dpkg --ignore-depends=libreadline6 -i wsjtx_1.9.1_amd64.deb

Monday, June 18, 2018

Sideband in GNURadio for an FL2K VGA dongle transmitting WSPR with the Weaver method

Ross, VK1UN, and I have been tinkering with the low cost FL2K VGA dongle which can be used as a high speed digital to analog converter capable of generating RF.

As the WSPR spots shown here indicate, Ross has been successful. This is a VGA dongle simply matched into a dipole transmitting a WAV file of WSPR tones from Melbourne to Tasmania.

Along the way we've both been learning about GNURadio (or really the graphical interface called GNU Radio Companion or GRC). It's a fascinating tool.

We've been trying to figure out how to generate modulated RF in a form that can be output by the dongle. Our approach has ended up as one of reading the modulation audio in from a WAV file and writing a sample file that is then sent to the dongle using the fl2k_file tool.

Doing things like filtering can be very slow in GRC when you're trying to generate the full RF waveform. Sometimes it has taken me an hour to generate a few seconds of RF.

Last weekend I discussed this with Peter, VK2EMU, while we were on a bush walk and he suggested the Weaver method of SSB generation. Ross has built this in GRC and it works in real time!

Download the GRC file from here. Note you'll need to update the input wav file source.

The generated upper sideband looks pretty good.

The Weaver method of single sideband generation starts by mixing the audio spectrum with a carrier in the middle of that bandwidth. This is quite different to traditional methods that mix up to RF and then filter out a sideband which is much more computationally intensive.

Thursday, June 14, 2018

Australian Government reviewing broadcasting into the Asia Pacific

If you have an interest in having Australia resume broadcasting into the Asia Pacific region again, like we did up until budget cuts resulted in an end to Radio Australia's shortwave services in January 2017, I urge you to respond to the review being conducted by the Department of Communications and the Arts along with the Department of Foreign Affairs and Trade.

It closes on the 3rd of August 2018 at 17:00 AEST.

The terms of reference are very broad, seeking to assess the reach of Australia's media in the region, and covering many distribution platforms - they mention television, radio and online.

The striking thing that's changed in recent years is the increased output from China which has in some cases taken over frequencies that used to be used daily by Radio Australia (which of course they have every right to do).

Technical things have changed too:
  • Digital Radio Mondiale has been rolled out in India (although receivers are still not very good)
  • Smartphones and mobile data are much more available in the region
  • Use of home satellite receivers has declined globally as more content moves online
  • Use of shortwave AM radios has diminished but it's interesting to note that there are many new models of radio available.
There are many benefits arising from broadcasting into our region from Australia, perhaps the best defence against Fake News is just the provision of consistent, quality, regular news. Tecsun Radios Australia has a great article on the value of shortwave in the region. 

You can find out more by joining the Facebook group "Supporters of Australian Broadcasting in Asia and the Pacific".

The Strategist has a nice piece by Graeme Dobell backgrounding some of the politics.

I had an opportunity to talk about this on ABC RN Drive with Patricia Karvelas. Former Pacific correspondent Jemima Garrett was interviewed the next night on RN Drive.

There has been some additional coverage:

My tiny camper van came with a Pioneer car radio that has shortwave. I notice that in the afternoons Radio New Zealand belts in to Sydney and could be mistaken for a local AM station.

Let me know if you see more stories I've missed.

Saturday, June 09, 2018

Fascinating talk by Hans Summers

Thanks to Bill's Soldersmoke blog for this tip. At the "Dayton" (not actually there any more) hamvention this year, Hans Summers gave a terrific talk about his distain for the archaic NE602 based transceivers and how it's time to upgrade the design using modern methods.

I recommend, grabbing the slides and then playing the Ham Radio Workbench podcast episode. You might like to seek in 1hr 20 minutes to where the talk begins. Hans has also published a paper with more detail.

Hans describes in detail how to generate quadrature signals from an Si5351 clock generator. Great stuff.

Saturday, June 02, 2018

FreeDV digital voice story on WIA broadcast via FreeDV

The recursion appeals to me, here is a story about the new FreeDV 700D mode complete with comparison with SSB. I heard the story via the relay over FreeDV 1600 from Adelaide.

Interestingly I find digital voice decoded is more intelligible in a small external speaker than in headphones.

After the broadcast relay, Mark, VK5QI conducted a callback on 700D with stations VK3PR, VK3RV, VK5DGR and VK5APR. We often got perfect signals despite some interesting selective fading such as this on VK3RV.

The broadcast on FreeDV is at 10am Sunday Adelaide time on 7.177MHz.

700D uses much less bandwidth than sideband, here's a waterfall comparison David VK5DGR sent me this morning.

One thing to note (it confused me) is that FreeDV uses the same sideband as normal voice on each band. This is unlike other digital modes which generally use upper sideband everywhere.

Installing FreeDV 1.3 on Ubuntu or Debian

Not everyone likes to build from source. You can download and install FreeDV 1.3 (which you need for the new 700D mode) as follows:

Download these files:

In a terminal go to the Downloads folder and:

sudo dpkg --install libcodec2-0.8_0.8-2_amd64.deb
sudo dpkg --install freedv_1.3-1_amd64.deb

Wednesday, May 30, 2018

Generating RF with an osmo-fl2k VGA dongle

I've continued to play with the cheap ($10) USB VGA dongles which can be used as a fast digital to analog converter. Working with Ross, VK1UN, we've been climbing the learning curve of  GNURadio Companion to generate the samples we need to transmit modulated RF.

The fl2k_file command line tool needs a file with 8 bit signed samples. These are clocked out at 100M samples per second by default.

To get started I've written some pretty inefficient c to write out suitable files.

First here's a function that writes a suitable simple sine wave carrier. (I use 80 samples per cycle to get RF on 1.25MHz).


const char *outFileName = "samples.dat";

void makeCarrier(int samplesPerCycle) {
    FILE *outfile = fopen(outFileName, "wb");
    int8_t byte;
    for(int sample = 0; sample < samplesPerCycle; sample++) {
double current_radian = M_PI * sample * 2 / samplesPerCycle;
        double carrier_sin_value = sin(current_radian);
        byte = (int8_t)(carrier_sin_value * 127.0);
        printf("%f, val = %f, byte = %d\n", current_radian, carrier_sin_value, (int)byte);
        fwrite(&byte, sizeof(byte), 1, outfile);

Double sideband can be generated by simply multiplying samples of a modulating sine wave by the samples of the carrier.

// Produces an double sideband signal suitable for fl2k_file
void makeDsb(int samplesPerCycle) {
    // ratio of the carrier to the modulating sine wave
    int ratio = 3000;

    FILE *outfile = fopen(outFileName, "wb");
    // make sure we get enough samples for a full wave of the modulation
int totalSamples = samplesPerCycle * ratio;
    for(int sample = 0; sample < totalSamples; sample++) {
double carrier_radian = fmod((M_PI * sample * 2 / samplesPerCycle),(M_PI * 2));
        double mod_radian = fmod((M_PI * sample * 2 / samplesPerCycle) / ratio,(M_PI * 2));
//printf("%03d carrier r = %f, mod r = %f\n", sample, carrier_radian, mod_radian);

        double carrier_sin_value = sin(carrier_radian);
        double mod_sin_value = sin(mod_radian);
        double am_sample = carrier_sin_value * mod_sin_value;
        //printf("%f\t%f\t%f\n", carrier_sin_value, mod_sin_value, am_sample);

        int8_t byte = (int8_t)(am_sample * 127.0);
        //printf("byte = %d\n", byte);
        fwrite(&byte, sizeof(byte), 1, outfile);

AM requires the modulating audio (ranging from -1 to +1) to have 1 added to it and the result divided by 2 before again multiplying by samples in the carrier sine wave.

// Produces an AM'd signal suitable for fl2k_file
void makeAm(int samplesPerCycle) {
    // ratio of the carrier to the modulating sine wave
    int ratio = 3000;

    FILE *outfile = fopen(outFileName, "wb");
    // make sure we get enough samples for a full wave of the modulation
int totalSamples = samplesPerCycle * ratio;
    for(int sample = 0; sample < totalSamples; sample++) {
double carrier_radian = fmod((M_PI * sample * 2 / samplesPerCycle),(M_PI * 2));
        double mod_radian = fmod((M_PI * sample * 2 / samplesPerCycle) / ratio,(M_PI * 2));
//printf("%03d carrier r = %f, mod r = %f\n", sample, carrier_radian, mod_radian);

        double carrier_sin_value = sin(carrier_radian);
        double mod_sin_value = (sin(mod_radian) + 1.0) / 2.0;
        double am_sample = carrier_sin_value * mod_sin_value;
        //printf("%f\t%f\t%f\n", carrier_sin_value, mod_sin_value, am_sample);

        int8_t byte = (int8_t)(am_sample * 127.0);
        //printf("byte = %d\n", byte);
        fwrite(&byte, sizeof(byte), 1, outfile);

To look at the output file, to see if it's reasonable, I wrote a utility to read the bytes, spit out a text file with the numbers in it, feed that into gnuplot and look at the graph. Great but I've just had a better idea, the audio editing software Audacity can import files and setting it to signed 8 bit PCM works well and the waveform is easy to see.

Here's how AM looks:

The file is transmitted with fl2k_file simply as:

fl2k_file samples.dat

The output AM can view viewed on a CRO.

And shown on an SDR, here it is in SDR#. You can see the carrier and two nice sidebands.

On an AM radio, I hear a strong carrier with nice sounding tone.

I realise this is all very basic stuff but it's been great to learn a bit about it. The real power tool in all this is GRC (GNU Radio Companion).

Here's how I generate an amplitude modulated carrier suitable for sending to the fl2k dongle. (Click to enlarge it so you can read it).

The GNU Radio flow document is here.

Note that GRC always defaults to complex and in this case we want floats. This will run indefinitely and fill up your disk so just run for a few seconds and then open the file in Audacity to have a look at the waveform.

To avoid local AM stations I've been sending it with "fl2k_file -s 80e6 am_out.dat" which puts it on about 900kHz on the broadcast band.

Here's a GRC flow graph that shows how I read a WAV file with audio (ELO don't bring me down), resample it up and produce AM'd carrier to transmit. (Again click to read it).

Here's how it sounds on an AM radio.

Anyone know how to do this but with single side band?

Update: Ross transmits decodable WSPR

Transmitting a captured audio output from WSJT-X on AM, Ross has been able to decode the transmission.

And again but with double sideband modulation:

Next challenge is single sideband modulation.

Monday, May 28, 2018

Sydney - Adelaide via FreeDV 700D. Better than SSB

It's 4:30pm Sydney time and I've just had a digital voice contact using David, VK5DGR's new 700D FreeDV mode. Sydney to Adelaide is about 1,100km so a good distance for 7MHz. My local noise level here is not great at about S6 and yet we were able to have a pretty good contact on 40m.

Version 1.3, which includes the new 700D mode, is available as a pre-built binary for macOS, Linux and Windows. I grabbed the latest development source and it builds according to the README on Ubuntu 18.04 just fine.

My set up is a USB headset mic and a Signalink USB radio interface. All works well although David suggests that decoded digital voice might be more readable via a speaker than via headphones.

We chatted back and forth in digital mode pretty well and then switched to SSB to compare. I was certainly putting out more power on SSB and I suspect David was too but to me the digital copy was as good as or slightly better than SSB. This is a fantastic milestone to reach!

Signal notification service

As there isn't a huge amount of FreeDV activity at the moment, there is a fantastic feature that can monitor and send an email if there is five seconds of sync. You run a python script included in the source and give it your email credentials. This script listens on UDP port 3000 and if you enable this in FreeDV's options screen it will email you when someone's on the channel. (It only sends one email a minute so you don't get swamped).

This is a great idea and should be a standard for other digital mode clients.

How I sound

We had a three way contact today on 7.177 between Peter, VK3RV in Sunbury Victoria, David, VK5DGR in Adelaide and myself, VK2TPM in Sydney. David recorded one of my transmissions and sent me the off air recording which can be decoded in the FreeDV app. We could barely hear each other in SSB. Here's how it looks and sounds:

Note that there are command line tools distributed with the FreeDV source code including freedv_tx and freedv_rx which will encode and decode all the way from voice wav through to modem audio.

Here's how you decode a captured file:

freedv_rx 700D vk2tpm.wav - | sox -t raw -r 8000 -e signed-integer -b 16 - decoded.wav

Note that the output file is a 16 bit mono file with 8kHz sample rate.

Check out the FreeDV site for much more information and give me a call on 7.177Mhz.

Monday, May 21, 2018

Home made ubitx box

Inspired by the excellent web site, I have bent a larger box so that the front panel ergonomics are improved. I added a nice tuning knob with finger depression and added a microphone pre-amp, compressor and noise gate board. The tuning knob is on its own on the right (not cramped with the volume control and mic socket) and with the new software it's a pleasure to spin up and down the dial.

I'm just using the mic amp board as it comes with a dynamic mic and levels look good but there's the option to add trimmers for both the compression and noise gate level. I have an output gain control knob in there.

My rudimentary metal work skills are slowly improving and I'm quite proud of the nibbled hole for the LCD display in this one. My nibbler has been sticking, which was frustrating, but a little WD-40 did the trick. I learned from a recent Adam Savage video that WD stands for "water displacement".

Saturday, May 05, 2018

Updated uBitx raduino software

Inspired by the latest edition of the Soldersmoke podcast, I took a look at the updated software that has been created for the embedded Arduino Nano.

My uBitx is looking much nicer since I made a new lid for it and mounted the speaker with a grill made of offcuts from the gutter guard we had installed last year.

I used the latest version of the Arduino IDE 1.8.5. Next I went to library manager and updated all updatable libraries and the same for boards. From the downloaded software from GitHub I opened the ubitx_20.ino file and did a build (the tick button). All built smoothly for me.

The Raduino board (sandwiched with the display) was removed from the uBitx, mainly because the position of my volume control blocks the mini USB port. I removed the display and plugged the board in to USB.

When I programmed it gave timeout errors saying that the board wasn't responding. I tried a different computer and different cables. Finally I tried the "old bootloader" option and all was good.

Along the way I first tried under Linux and then on macOS. The serial driver I needed was found via Bjorn's Techblog.

Now the uBitx is much nicer to tune and there are lots of interesting menu items to explore.

Some of the features are:
  • CAT control
  • S-Meter
  • Software defined radio output
  • Improved receive performance
  • IF Calibration
  • WSPR beacon
  • Bug fixes including CW key debouncing
Great work by KD8CEC and others on all this and of course credit to Ashar Farhan for creating the uBitx and making it all available for hacking.

Update: uBitx to uBitx contact with VK2BLQ

Encouraged by the improved tuning action, Stephen and I had our regular 20m sked with uBitx rigs on both ends. Stephen could hear me over the local noise and I could hear him pretty well when he "talked it up". Both of us have been reading the ubitx site and have independently ordered a low cost mic amplifier/compressor board.

I'm now keen to re-box my uBitx to give more room for the tuning knob. I'm looking for a knob with a finger indent that will screw on to a 6mm shaft. They are about but seem very expensive generally as an after market add on for a commercial rig.

We're also interested in digital modes on the uBitx and of course the best way to do this would be to build in a USB audio interface with VOX. Not sure that I'll go that far but worth thinking about.

Monday, April 30, 2018

First play with OSMO-FL2K compatible VGA dongle

Everyone knows about the popularisation of software defined radio that came about via the wonderful discovery that low cost USB TV dongles with realtech chipsets could be used. Now it looks like we have the same sort of thing but for transmitting.

Some low cost USB VGA adapters are so cheap that they are simply fast digital to analog converters. Steve M from Osmocom has figured out how to turn them into a simple output device suitable for transmitting. Mine came from Aliexpress but others are on eBay locally.

Here I tried a device and used the demo program to transmit an audio file (saved as WAV) over wide band FM to a nearby radio.

I'm on Ubuntu linux so there were some very small deviations from the instructions about USB memory buffer, I had to do this:

sudo sh -c 'echo 1000 > /sys/module/usbcore/parameters/usbfs_memory_mb'

To get some audio to transmit, I opened a 44100 rate mp3 in Audacity and saved it as WAV signed 16-bit PCM file.

The command line to transmit is:

fl2k_fm -s 130e6 -c 35e6 -i 44100 Electric\ Light\ Orchestra\ -\ Telephone\ Line.wav

So far other examples, and there are some amazing ones, require GNU Radio, but hopefully we'll get some more accessible ways to do interesting things like transmit WSPR in the near future.

This is a wonderful example of where the cheaper product is actually more useful than the more expensive versions.

There is a pretty good explanation of how this works in an earlier project VGASIG.

Here's how it looks on an SDR receiver. A little off frequency but looks reasonable to me.

And here's how the 35MHz waveform looks on a CRO:

So when working it's a decent 0.5V peak to peak waveform, DC offset. And a good signal on an FM radio at 95Mhz

I have noticed that this software/hardware works on some Linux machines and not others. It works fine on an Ubuntu 18.04 desktop but not on Fedora machines. When running on some machines it fails silently in that all appears to be running but there's no RF output.

Using the fl2k_file utility I output a sine wave. I can see the sine wave in the dongle output but there is lots of nasty spikes too. I guess a low pass filter could clean this up but it's not a good look.

Please let me know if you've got a better result than I have.

Update: Now getting a better waveform.

I've done some hacking on the FM code, basically stripping it right back and focusing on generating the cleanest wave I can on 40m.

This is running at a sample rate of 150Mega samples per second and a carrier of 7.159MHz. Not great but might be eventually useful (with some filtering) for something like WSPR transmit.

My stripped back version of the source now builds stand alone (no library) and simply generates a sine wave carrier. The source is available here.

Made a small project box

I'm not very good at this and figuring out how much extra to allow for the bend in aluminium continues to elude me but gradually I'm getting there.

The box shown here is still pretty rough but it's good enough for my little projects. Being able to make them at home means I can adjust the size to suit the project.

This morning I looked up Aluminium in Google maps and lucked upon Aluminium Engineering near by in Brookvale. What a wonderful establishment. I purchased a sheet of 0.9mm aluminium and loaded it in to the van.

The shop front is a work of art and should be classified as a heritage building to be preserved for ever.

Inside they're well stocked and the two chaps in there are friendly and informative. The warned me not to try welding 0.9mm which is fine.

Here's the shiny new hand shear which is making all of this cutting pretty easy. A cat is shown for scale.

Here is the current iteration of my box plan.

The measurements in the lid on the right are based on 0.9mm thickness and my dodgy bending. As you can see this makes a 100mm x 100mm x 40mm box. I'm using self tapping screws on the sides and it needs rubber feet to avoid scratching tables.

Sunday, April 29, 2018

Metalwork upgrade - a hand shear to make boxes

I'm terrible at metalwork. Cutting even 0.5mm aluminium sheet is difficult with a hacksaw or jigsaw. Today I went on an expedition to machine tools supplier Hare & Forbes and it was a great place to look around and the staff were friendly.

Half the battle is working out what things are called. I bought a "hand shear" which is like a heavy duty guillotine operated by hand through a big lever. While they had them from $99, I spent a bit more ($169) to get one with a 300mm blade length.

I have owned a small hand brake metal bender for some time but the inability to cut metal cleanly has hindered my use of it so far. Hare & Forbes have a great range. The one I bought is second from the left.

As a first project I bought a rectangle of 0.5mm aluminium and re-made a box lid to replace one I messed up for the uBitx.

My dream is to be able to make small custom boxes for projects. There is much to learn but happily YouTube is a great place to see how to operate this kind of equipment. Peter, VK2EMU, kindly sent me a link to this video about making Aluminium enclosures from Chuck Adams, K7QO.

I've had a shot at a small box out of 0.5mm aluminium.

It's pretty rough but not bad for a first attempt. The trick is to make the top part wider than the lower part by the right amount.