QSB-01 (qrp-tech synchronous buildathon) #7 – Final Details – Custom Case Decals

Having spent a lot of time building my 1 Watter I wanted it to look half decent in its enclosure and had a good look around at my options for labeling up the case with something funky to do it justice.
As big a fan of the old Dymo labeller as I am, I’ve never been 100% happy with the finish I’ve achieved when I’ve used them. Although functional they’ll never win any prizes.

A bit of research unearthed the idea of custom decal printing. This is something I’d never even considered. Bearing in mind the number of Airfix models I built as a kid, it never crossed my mind that things in that department had evolved with the whole IT concept of “print your own”.

My favoured option would have been to use the media which you run through a laser printer to give the most crisp output, but not owning one and in a similar vane to the Dremel bench saw project, I wasn’t about to go and buy one for a single job, so left it in the hands of my Epson Stylus Photo R360 to see what it would do with the ink jet media.


Mr Decal Paper (real name not me being flippant) on eBay supplied the decal sheets and the instructions which made life a bit easier. You need to seal your printed sheet with spray varnish to prevent the immersion in water stage from causing everything to run off the page. A trip around the art section of The Range provided a solvent based product rather than a water based one which would have defeated the whole object.

I designed the decals in a combination of PaintShop Pro, MS Paint and MS Word. The dry run on plain paper was spot on but the actual print on the decal paper was less than polished. I’ve had this before with ink jet inks not wishing to play ball with media other than the massively overpriced product from the manufacturer. As Epson don’t produce a decal paper I’ve got to live with it.

Now despite my anticipation of thunder storms on a Bank Holiday weekend, the weather proved me wrong and in effect was perfect for turning the garden washing line into an impromptu spray bay.


My three coats took seconds to dry in the heat but I still gave it ample drying time between applications to prevent any mishaps.

The next morning brought judgement day along with an assessment of my ability to accurately cut things out with a slide cutter and pair of scissors.
Like the Airfix kits of the 70’s a quick soak in water releases the decal from its backing sheet allowing them to be applied.



Not bad for a first attempt! The instructions suggest a drying time of 24 hours or a spell in a low temperature oven to harden the decals dependent on the surface they’re applied to. I’m not sure my 1Watter would see the funny side of that!


QSB-01 (qrp-tech synchronous buildathon) #6 – And the fat lady sings!

So after several weeks / months of interrupted building we’re there!

Now admittedly it’s not in the enclosure I wanted to build, which was this

Screenshot 2016-03-09 14.41.42

but you can’t have everything! A PCB enclosure requires the ability to cut reasonably straight lines in your medium with repeatable accuracy. To do this I was planning on using a Dremel mounted horizontally in a 3D printed purpose made frame which converts the drill into a bench saw. Unfortunately part way through printing, my good chum Mat’s printer decided it had had enough and requires a bit of rebuild work and maintenance to get it back working. As such I don’t have a completed table/platform for the Dremel holder.

That said, every cloud has a silver lining. A Dremel would have set me back seventy odd quid, plus the additional hardware for the frame. The cheaper solution was an LMB/Heeger CR-442 painted enclosure from Mouser. Even with the duty charges and shipping I was out for less than a third of the cost of the Dremel saw table project and probably got to keep a few more fingertips into the bargain. If I build another 1Watter (and I will) I’ll look to box it in the bespoke built enclosure if the printer is back working.

So (drum roll please), here it is!





If you want to save yourself several hours with a set of calipers and some graph paper trying to work out what will fit where (and it is tighter than the proverbial in there!), here’s a copy of my drilling template. Print it at full size A4 and you’re good to go.


OK, the enclosure needs a bit of artwork to liven it up and to make sense of the controls and connections (separate post for that bit) but the soldering iron is officially cold!

Now on first reveal to those at home, I got a “Ah, isn’t it cute!”

Not what I was expecting! I was trying to build the QRP equivalent of Dr. Heinz Doofenshmirtz’s “Inator’s Inator” here (you have to watch Phineas and Ferb to truly get that one I’m afraid) so people cooing over it is not what your kick-ass QRP radio wants to here. That said it’s a nifty little package.

The best part of a day was spent tinkering with the final setup and alignment as per Chuck’s YouTube video #9.


This one’s a must. I was really surprised to discover how serious the relationship between the adjustment of C24 and C25 was when aligning the transmitter. I was wondering why I was seeing absolutely nothing on my power meter when I was keying until, Boom! The power was rocketing past 1W in a hurry. All good stuff.

As part of the build up to this project I invested in a frequency counter from eBay. The supplied item turns out to be a PLJ-1601-C which comes with absolutely nothing. Google provides you with a manual in one flavour – Chinese. So, with a little bit of effort here’s an English language version I made using Google Translate.

PLJ-1601-C english translation

PLJ_1601A – chinese language

It’s free and comes with no warranty, acceptance of liability etc etc etc. Just be grateful someone made your life easier for you rather than having to attend night school to learn Cantonese!

** Addendum 29/07/16 – Many thanks to Trevor Newstead who has noticed that for some bizarre reason all of the images have disappeared from my english translation version. I will look to redo the document at a later date but in the short term the original Chinese language version has been added for reference. If you look at the two side by side you can see what’s what. Sorry! it’s on the todo list

With the frequency counter attached to the antenna and everything on a dummy load I get a tuning range of 14.055.86 to 14.060.49 MHz.


Unfortunately I still can’t get the hang of my Homebrew oscilloscope to get anything sensible out of the frequency analyser to check the spectral purity during transmission, so that’s a job for another day. That said I have managed to get my DS203 to do something useful. Here we’ve got a nice sine wave on keyup!


The final stage is to design some case graphics, check the output for harmonics and sort out a throw up antenna so I can play outdoors in the sunshine. There’s no point in building a portable rig and sitting indoors when the sun is shining outside is there?

QSB-01 (qrp-tech synchronous buildathon) #5 – transmitter build updated @ 21/05/16

Phase 15 – Final RF Power Amplifier Stage

Commenced 02/05/16  Completed 02/05/16

Phase 15 completed

Completed build requiring fitting in an enclosure, setup and alignment








Phase 14 – Third Driver Stage

Commenced 02/05/16  Completed 02/05/16

Phase 14 testing


Audio file – Phase 14 testing


Phase 14 completed



Phase 13 – Second Driver Stage

Commenced 02/05/16  Completed 02/05/16

Phase 13 assembly work


Phase 13 testing


Audio files Phase 13 testing



Phase 13 completed



Phase 12 – Transmit Band Pass Filter (BPF) & First Driver Stage

Commenced 28/04/16  Completed 02/05/16

Phase 12 assembly work


Phase 12 testing


Audio file – Phase 12 testing


Phase 12 completed




Phase 11 – First Transmit Mixer

Commenced 27/04/16  Completed 28/04/16

Phase 11 assembly work


Phase 11 testing


Video file – test operation of the first mixer stage


This testing stage is clever in that it is using the receiver to test the transmitter in a feedback loop where the output of the first transmit mixer is fed into the antenna input. This comes with a caveat of don’t do this under any other circumstances else risk destroying your creation! In the above video the audio output of the keyer has been switched off by entering the command mode and disabling it. As such the tones which are heard are those being produced by the transmitter. The technique negates the need for any test equipment which is a bonus for those without those resources to hand.

Phase 11 completed


I’ve corrected the display unit now by adding the IF frequency to the display’s memory function. Now it adds 6MHz to its received input giving a more accurate and usable reading


Phase 10 – Keyer & Keying Circuit

Commenced 26/04/16  Completed 27/04/16

Phase 10 assembly work


Phase 10 testing


Video file – Keyer Circuit test




Phase 10 completed




1Watter YouTube video resources

The following videos were produced by Chuck Adams K7QO and although they don’t follow the step by step guide as per his website they are a very useful resource especially phase 9 (final alignment and testing) and phase 10 (introduction to the 1Watter keyer)

Phase 1

Phase 2

Phase 3

Phase 4

Phase 5

Phase 6

Phase 7

Phase 8

Phase 9 – Testing and alignment of completed 1Watter

Phase 10 – 1Watter keyer

Aluminium enclosure construction

QSB-01 (qrp-tech synchronous buildathon) #3 – receiver build updated @ 26/04/16

Rather than loads of posts, this blog is going to be my notebook for the QSB-01 in a rolling style. Also, rather than bore you to death with a blow by blow account it is simply going to be the necessary photo or answers requested by Yoda (Chuck Adams K7QO) at the conclusion of each phase of the build, along with a few others where relevant.

For it to all make sense have the necessary QSB-01 web pages one and two to hand.


Phase 9 – LPF Section

Commenced 12/04/16  Completed 26/04/16

It’s taken two weeks to insert 5 components! That’s what happens when servers go wrong!

Phase 9 assembly work


Phase 9 testing


Video file – Phase 9 testing of completed receiver section


Unfortunately, on the day the band was closed with absolutely no QSO’s to test the receiver against which is a real shame.

Phase 9 completed




Phase 8 – TR/BPF Section

Commenced 12/04/16  Completed 12/04/16

Phase 8 assembly work


Phase 8 testing


Phase 8 completed




Phase 7 – Advanced Testing Addendum

The display unit as it stands is pretty good but would be vastly improved by calibrating it, as the supplier comments that it shows 100Hz error when checked against a 10MHz reference standard. There is a trimpot on the board which allows calibration but I don’t own a DDS Frequency Standard. Remember the old “How to Build an Atomic Clock” post? Yep, that rubidium standard would really come in handy now!

Now without anything like that readily available, in a flash of inspiration/desperation I remembered my Elecraft XG2 Receiver Test Oscillator that I had paid a stupid amount of money for (129€’s to be precise!) when I was setting up my SoftRock Ensemble.


So at 4.3€ or £3.34 per component it seemed silly not to see if it would do the trick as it provides 50uV and 1uV signals for 80m, 40m and 20m.

In short, it didn’t, which is a pain, but thankfully I’ve found someone with a 10Mhz frequency generator who will be able to loan me 5 minutes of their time at some point to calibrate things.


Phase 7 – Impedance Matching Transformer T4 and Band Pass Filter

Commenced 06/04/16  Completed 06/04/16

Phase 7 assembly work


T4 torroid transformer 4T:28T



Phase 7 Testing



Audio file – power up, no wire, 15cm wire @ L3, 15cm wire @ L3 adjustment showing two peak positions


Phase 7 Advanced Testing

This required a separate build of a digital display unit. I went for the one plugged by Chuck at http://www.qrpguys.com/




Having set my mind on a final enclosure and so forth building the display threw a spanner in the works as it’s a really cool addition. As such I built it so it could be enclosure mounted (trimmer pot and push button mounted on the rear rather than front for easy access once mounted).


Once built the display is attached to the header at J7. I added a tuning pot at J1 to allow testing



My camera struggles under all the lighting on my bench to show the display with the clarity it provides in reality


Video file – Phase 7 advanced testing with the display attached to the VXO


Now the astute amongst you would have noticed that the display is saying 8.0628MHz. For 20M you’d be expecting something around 14MHz, which you get from mixing the VFO frequency with the IF (intermediate frequency) of the receiver. The display is taking its single input from the VFO, which is variable. The clever bit comes in that the display can be set to add or subtract the IF. In short you plumb the display to the IF at pin 7 of U5, power it up, hit the button on the unit and it saves it to memory. Now, when it is reattached to J1 it takes the value from memory and adds it to the input value giving you your desired frequency. It really is that simple!

Phase 7 Completed




Phase 6 – Variable Crystal Oscillator (VXO) Section Testing

Commenced 06/04/16  Completed 06/04/16

J1 Voltage = 9.94V

Audio file – 15cm wire placed at pins 1 and 2 of U4





Phase 5 – Variable Crystal Oscillator (VXO) Section

Commenced 05/04/16  Completed 06/04/16

Phase 5 assembly work








Phase 5 Completed




Phase 4 – IF Crystal Filter

Commenced 02/04/16  Completed 05/04/16

Phase 4 assembly work




Phase 4 Testing

15cm wire placed at pins 1 and 2 of U4


Phase 4 Completed



Phase 3 – Audio Detector Mixer (BFO) Installation

Commenced 27/03/16  Completed 29/03/16

Phase 3 assembly work



Crystal testing


Not all crystals are equal! Two showed fluctuation between 5.9993-5.9994MHz with some stability after running and warming up(?)

Winding T5 binocular toroid

Hardly blog worthy other than the instructions at Kitsandparts.com aren’t very clear and never having wound one of these before it was worth noting for future reference.


In one hole and out the other constitutes ONE turn. As such if TWO turns are completed there will be TWO “wraps” of wire visible at one end of the toroid and ONE at the opposite end


20160327_171718 (1)







The magnet wire in the kit isn’t marked and is supplied all in one bag! Now bearing in mind the difference between some of the gauges is fractions of millimeters a fair amount of time was spent checking and double checking with a set of digital calipers and then clearly labelling each to prevent any cock up!

Phase 3 Testing

On power up hiss heard BUT no difference in noise heard when 15cm wire touched on upper pad C32!

Phase 3 Advanced Testing

When a crystal oscillator with a 6MHz crystal is placed next to the 1Watter at this point in the build a distinct oscillating tone is heard.

The lack of any tone change being heard at basic testing was nagging so I sought advice from Chuck on this one.

His advice was to place the crystal oscillator away from the radio and then place the 15cm wire on the non grounded pad of C32.

With the oscillator 10″ from the board, with no wire nothing can be heard. With the wire touched against the pad the oscillator can be heard as clearly as when they are next to each other. Chuck’s advice, if you can hear that all is good! The suggestion is there’s insufficient electrical noise within the house to up the background noise, hence the lack of response at basic testing.


Phase 3 complete




Phase 2 – Commenced 27/03/16  Completed 27/03/16

Phase 2 Part 1 assembly work


Phase 2 Part 1 assembly completed


Reverse side of PCB


Highlighted section of schematic reflects completed build on PCB

Phase 2 Part 1 Testing – A/C hum test at C37 & C38



Phase 2 Part 2 assembly work




Phase 2 Part 2 Testing – A/C hum test at U5 pins 4 & 5


Phase 2 Part 2 Complete




Phase 1 – Commenced 27/03/16  Completed 27/03/16

Homework Completed 


Ordered & Delivered 1Watter 20m kit – S/N 60720160319_103320

Phase 1 Assembly work


Phase 1 assembly completed – Jumper power connection to PCB & completed power supply section


Reverse side of PCB showing solder connections and stand off spacer


Highlighted section of schematic reflects completed build on PCB

Phase 1 Testing


Voltage test at C7 top pad – 12.65V, battery voltage – 12.72V


Reversed polarity voltage test


Further voltage checks at U6-6

Battery = 12.72V, Voltage at C7 = 12.65V, Voltage at U6-6 = 12.66V

Enclosure considerations 


1/ BUD Industries aluminium enclosure available from Mouser – commercial option

Screenshot 2016-03-09 14.41.42

2/ QRPbuilders double sided PCB enclosure for 1 Watter – homebrew