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Lockdown Projects

I’ve wanted to have a go at having some PCBs made for a while (years actually!). I have made a few attempts at getting going with CAD software but I always found the learning curve too steep. At the RSGB Convention in 2019, I was chatting with Dan, M0WUT (occasional SOTA activator, keen CW op, PCB wizard and Yorkshireman like me :slight_smile: ) and he encouraged me to have another try with PCBs and promised to be at the end of a message should I get stuck.

With Dan’s tips and encouragement, I put together my first circuit board in Kicad a few months ago. The learning curve was very steep for me, and my poor little netbook seems to be under powered for the task. However I persevered and I was excited to have the design turned into a board.

After Christmas I decided to attempt a more complex project and I have recreated a classic QRP rig. The schematic and firmware is contained within the ARRL Handbook CD, which comes with the ARRL Handbook. My Handbook dates from 2012 and I won it at the G-QRP Convention at Rishworth.

I produced the necessary files over a few weeks, doing a little bit at a time. I used JLCPCB to manufacture the boards, it was a simple process of uploading the .zip file containing the 8 PCB Gerber files. The JLCPCB tagline is 5 PCBs for $2!

Whilst waiting for the PCBs to arrive I ordered some 12C508A PIC microcontrollers. The 12C508A is an ‘OTP’ part, which means One Time Program. Basically you’ve got one shot to burn the code! Thankfully my cheap Chinese hobby grade PIC programmer worked absolutely fine and I burnt 4 chips without a problem.


K150 PIC programmer burning the .hex


Test mule, testing the home burnt chips.

The PCBs arrived on Tuesday, around 2 weeks after ordering, and they are very nice.

I’ve had a few sessions carefully building a board, checking things as I go. I’m pleased to say that my board fired up first time with no debugging necessary, I even got the dits and dahs the correct way round!

Yet another rig to add to my SOTA rig pile to try when lockdown is lifted!


Drawing the circuit board in Kicad - (3D view mode)


Pleased with the PCB


I tested the shunt regulators first (didn’t want to fry the PIC!) then added other components.


Board finished.


Built into the almost obligatory Altoids tin case.


500mW output on 40m

73,
Colin
M1BUU

(Full credit to Dave Benson, K1SWL for the original design and PIC firmware)

27 Likes

You can replace that with a 12F508 - it’s pin and code compatible.

I finally got my SMT version finished too, and managed runner up in the RJV G-QRP contest.

https://www.tuckley.org/qmite/

Most impressive Colin. This story, together with your first activation with this kit (whenever that happens) will be getting distributed to the press list. So you can expect some more glossy magazine and web fame!

Well done Colin. Besides your undoubted electronic skills, you must have the freshest breath in Yorkshire :wink:

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I make lots of digital electronics PCBs for fun and I actually have a board design for a “MegaPixie” radio ready to go when I feel confident enough. It’s a v4 Pixie with all the best mods from around the web stuck in to the schematic, like sidetones and a better filtering section.

I’m a little scared about antenna impedance though and how exactly I make sure my board is 50 Ohm. Is it just the trace to the antenna that needs that, or does the entire board need controlling for that somehow? I’ve never done an RF board before.

Just had these Atmel kit boards made prior to Christmas btw, lots of fun: https://pentler.blogspot.com/2021/01/shitty-amateur-construction-part-13.html

Ha!

I’m vegetarian! :slight_smile:

An ex colleague married a girl from Iowa and he used to bring me tins from the US. (I ditched the contents!)

My stash of Altoids tins is now used up. I have some Stewarts tins waiting in the wings (pardon the pun!) http://stewartstins.com/ranges/classic-collection/classic_collection-50g_extra_strong_mints/

73, Colin

2 Likes

No need to worry Mark, certainly at HF the tracks are so short in terms of wavelength that the effect will be negligible and any stray capacitance or inductance is swamped by other circuit elements.

More of a black art is working out the output impedance of the device(s) that are generating the RF, and matching this to give 50 ohms at the output. A degree of suck it and see is usually inevitable…

Good luck with the Pixie clone, look forward to seeing the details!

73 de Paul G4MD

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I have a Psi PP404 Wide Carriage Dot Matrix Line Printer in my Attic.
I spent a few hours writing a program that would take an ADIF log file and convert it to a fixed width log file suitable for printing. I then took my entire collection of contacts, some 3000+ and printed them out on green-ruled paper.

I think this counts as a valid lockdown project…

Complete madness… however, there is something about the weight of wide carriage printer paper which is quite magical, even apart from the hopeless nostalgia trip.

Mark. M0NOM

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A creative idea. And any plans for the printout Mark? Wallpapering the shack?

Joe

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Class job there Colin, you’ve upped your skillset substantially. I haven’t done any PCBs in a while but found laying out tracks and components hugely therapeutic, can’t quite decide why, it is like doing a 3d jigsaw but with an end purpose…

If you decide to turn your hobby into a business I recon you’d do alright mate.

Regards, Mark. M0NOM

It’s too legible. You need a printer that’s printed out a few boxes of paper every day for years so that printout is difficult to read. And a more worn ribbon.

But really you want all those QSOs on punched cards… boxes and boxes of them so you can “easily reupload your log”.

I hope you printed a nice burst page on the front so you who it’s for and where it was printed and a whole raft of meaningless numbers. Just like in the old days.

:slight_smile:

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I didn’t - it was printed from a linux queue, if I’d have done it from VMS something like this you mean:

Oh yes, them were the days!

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My projects are more prosaic and mainly centered on the house.

However, as a treat I’ve “enhanced” my SOTA ride with a 2.5” lift to accommodate humongous 35” tires. Entirely unnecessary but I can almost drive over a Prius.

In the Jeep world 35” tires are small…

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I was an VMS/OpenVMS system manager for 15 years. I instantly recognized that burst page.

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Hi Richard

When able I run a meeting every 18 months or so called DEC Legacy up here in the Lake District England - folk bring all sorts of computers but it is generally related to Digital Equipment Corporation in some fashion. In the first year we had two guys from The Living Computer Museum in Seattle attend.

My path crossed with DEC gear for the first 15 years of school, college and working life.

Unfortunately now the only interaction is at home. I pruned my collection a few years ago but I still run emulated systems connected to HECnet using SIMH for VAX/VMS and FreeAXP for Alpha VMS.

Regards, Mark.

It’s intriguing in that I have used VMS for only a few weeks over the last 38 years of work. Just about everything VAX was either BSD 4.3 or Ultrix. I had a VAX 11/730 with BSD4.3 all to myself for 2 years… it was a cute thing with about the same horsepower as an original RPi ! My short exposure to VMS was an Alpha VMS system where the production ADA compiler was hosted for a SONAR and I was drafted in with when it was “all hands to the pump”. I remember VMS DCL being terribly wordy and verbose compared with various *nixes and Powershell reminds much of DCL.

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Or cutting it up for toilet paper in lock down

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Or cutting it up for toilet paper in lock down
As bad as my schooldays Izal brand I imagine. OUCH!

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I remember it well, it should have had a warning sign like this:

73 Victor GI4ONL

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so… several months later mystery solved. The reason for the UK toilet paper shortage was not that Andy was storing it in his freezer but that the paper plants had been temporarily re-equipped to produce wide carridge printer paper to accomodate lockdown projects :slight_smile:

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