40m propagation / Kanga Kit / Intermediate Exam news !

Its been a lovely warm weekend down in Dorset, and that seems to have affected the propagation. I had a great time on FT8 and JS8 Call, reaching amazing distances and really good signals being put out and received. I had many logged contacts and good signal reports.

40m got *busy*

By the evening 40M got as busy as I have *ever* seen it, as shown in the picture above i switched about the bands and was making contacts on 15M as well, it was the best conditions I had seen so far !

Resume work on the Kanga Kit !

After a break of sometime, I have resumed work on my Kanga Kit – this fits in with the news I’m putting below, but I have a big thanks to John Clements who helped me fix a fault with the kit I was unable to locate. John found the issue (soldered pin-header together – hidden by the plastic) and returned the now working Kanga kit to me ! I have resumed work and am taking my time – I’ve completed more work on the resistors and capacitors on the Active BPF.

kanga kit with added capacitors for BPF stage

I’m taking my time, esp as the board is now quite ‘busy’ – the next step is to add diodes and IC’s. Its really close to completing the build, but taking my time to ensure no more mistakes !

RSGB Announce Intermediate Exams on-line !

As shown in the picture above from the RSGB site Intermediate exams will be available from the 13th ! (in 8 minutes time as of writing) i’m very excited that i will be able to book my exam and get use more wattage but also gain more insight to a very interesting hobby as I continue my amateur radio development.

Whilst the practial assessment is waived currently, i will continue to build my Kanga Kit, so if the issue did come up of what Kit I did build, this is well recorded and documented.

To close the evening off I had a splendid evening enjoying the good propergation and just listening to the QSO’s on 40m. The ICOM’s filter and noise blanker are amazing, SSB has never sounded so good.

The waterfall is incredibly useful for visualising contacts

What i really like about the 7300 is the ability to visualize all or in very close range the frequency. I can easily find conversations happening and enjoy what is being talked about and the signal reports. Almost everyone i hear on 40m is using 100W but the distances are still several hundreds of miles – in particular hearing about life on Guernsey was very interesting – seems they are Covid free and back to some ‘normality’.

Well, heres waiting on being able to book my Intermediate Exam and enjoy more contacts around the world !

  • UPDATE – Have booked Intermediate exam today (13 June) for in August for more time to do a structured revision plan and passing !
  • Am still planning to finish my Kanga Kit ! making daily progress !

73 / Alan / M7ALU

Kanga DX Direct Conversion 40m Receiver Kit – Stage 3: VFO & VFO Buffering – Tuning and use of oscilloscope

So having got the lab somewhat tidy (pics and a full reveal will come soon !) i can continue working on my 40m Receiver Kit – having wound the toroid and secured it previously, the next step was to add the components and buffer around the tuning circuit.

I would like to point out (maybe again) that one thing that i think is very much missing from this kit is a schematic of the ‘blocks’ of the decoder. At this stage it would be very much helpful to understand what components and how the modules worked together, in particular when we get to the stage of the ‘decoder’.

Capactors, IC’s and variactor Diode !

I found getting most components on the ‘push-thru’ was easy enough, the only components which presented a ‘challenge were the NPO and Polystyrene capacitors. As you can see the round circles for C27,C28 and C30 are ’round’ enough when the capactiors are verticle.

Capacitor mounting

On the first attempt i tried the ‘test’ method of using a radio tuned to 7Mhz and got nothing at all. It also didnt help that I didnt know what i would be looking, or in this case listening for. I took a break and came back to it the next day.

visually looks fine, but actally a dry join on the trim.

Tracing my work I found that i had left a slight dry join on the trimmer. As i have now aquired an oscilliscope I thought it was the perfect use to find the frequency and adjust it.

We have a 7.5Mhz frequency!

I was so happy to even see a signal on the oscilliscope and also the read on the frequency was not so far out from the 7Mhz. I was lucky enough that the oscilliscope probes come with tuning screwdrivers which are the ‘safe’ type required to tune the trim. I set about tuning to 7Mhz !

Close to 7Mhz

On the scope i could the frequency to read between 6.90nnn and 7.000nn. I thought about trying to see if I could hear anything on my handheld standard (AM) and my transceiver which has more modes (including CW & PSK) as well as specific filters.

7Mhz = beeep

I was very happy to pick up a clear signal on 7Mhz. What was interesting also was that where i have the probe into the VFO / Decoder board, it had turned the ‘wire’ into a small resonant circuit – in fact I could turn my VFO into a theramin ! After 15 minutes of playing wooping noises I set about completing/and tidying the kit up.

I’m really glad that the receiver is going so well – its been all the work I thought it would be but its now very satisifying, esp as its gets more complex.

DSO138 Digital Oscilloscope Kit

Prior to today

So I have been working on this kit in preperation of my Intermediate Practical exam. This isnt the kit I would use for submission, but I felt it was a good next step up from the voltage meter I have perviously made – this had quiet a few SMT resistors and several chips to add.

The component tester – a good first kit after years away of soldering/building kits, and useful !

I was able to utilize the component testing tool several times, for resistor values, transistor verifcation and capactiors. Some of the resistors are of very low value and wouldnt register, but was able to work those out via omission.

Recording a signal from a voltmeter

I was honestly amazed this worked first time, there was just so much which could of gone wrong, from over-heating transistors, components in wrong ways or shorts – but no, it worked first time ! I was really amazed, it had taken me about 5~6 hours in total time. I had a break of several weeks since my last build as I have just been so busy with my day work and rather tired during the evening (and very busy in the evening !).

Generating a signal from a voltmeter allowed me to test all the functions

You may notice one thing in the above pictures… I had forgotten to put the reset button on ! Thankfully this was in an easy to reach place and not so difficult to put on after the screen had been fitted (which does come out, but is a PITA to align).

My next kit is a signal generator and a frequncy counter where I will calibrate both the osclliscope and enjoy a digital read out, after that will come the Kanga kit for morse decoding, which should coincide with my HF antenna going up 🙂

Prepping for the Intermediate

Although I enjoy using 10W and can make enough contacts, the thought of getting my intermediate was a scratch I couldnt stop wanting to itch.

So I have booked.a weekend class and exam. I’m now using my commute time to study the Intermediate Study Guide, which I have to say is very accessiable and whilst a step up from the foundation, its the right level of challenging.

I’m looking forward to being able to operate on 50W of power (which seems huge to me right now, given I’m on 10 and less usually !). One requirement of the intermediate is to build a radio related electronic device to show practical skills.

I haven’t done any ‘proper’ kit building since my teens, probably whilst at secondary school. So I thought it best to practice first on a interesting kit, and make sure I build up my skills/knowledge.

I ordered the KKmoon Multifunctional Transistor Tester from Amazon which looked challenging but not impossible. I also made sure i had the best chance of sucssess and got a few helping things.

The BURNTEC PCB Holder Clamp, at just shy of 8 quid has been fantastic. Having only used a ‘helping hands’ before, I found this to far superior in bouth build and the ability to flip the board over. It really is a good piece of kit, being both strong and easy to build/configure for various size boards. I think the biggest it would do would be around 7 inches, plenty big enough for type of projects I’m doing currently.

The YOCTOSUN Hands Free Magnifier with Two LED Light has been great for working on the very small parts. As I already glasses, this fitted over everything really well and illuminated the parts perfectly. The strongest magnification has a bit of distortion on it, but otherwise the magnifer combinde with the clamp holder make a far superior fabrication process than the classic ‘helping hands’.

I set about soldering the resitors in first, then checking them all with a voltmeter for the correct levels, i.e. 1) i had read them correctly and got them in the right place 2) they worked. Which amazingly they did. Bouyed on by the resitors i carried on with other components.

Whilst the instructions are sparse, they are practical, giving the best order to put the components in, and also including the direction of how to place them. I did have to google a couple of components (diodes) to verify the right component, but otherwise the electronic build instructions were good.

For the transistors I used a crocodile clip to attach to it so it would draw the heat away from the component. It was funny using a skill i hadnt used for so long again !

I competed soldering everything in, and I think as i progress, the soldering does get better. A friend has pointed out some which could be improved, but this was my first time in quite a while. Overall I was happy with the results.

After about 3 hours of building i got to testing, and amazingly it worked first time ! I did have to fettle the display port a little (i.e. wiggle it a bit) to get into the case, but everything did fit and it worked perfectly.

I am very happy with the practice I got and now have a working test unit for various components.

I’m looking forward to building my ‘Kanga DX Direction Conversion Kit’ which whilst still looking challenging, isnt quite as scary as before completing the mutifunctional tester.