Manufactured PCB for Termination Insensitive Amplifier

The termination insensitive amplifier described by W7ZOI & K3NHI is a useful building block for the RF home constructor. I've been making these using copper pads glued on to copper boards but wondered if there were PCB designs available. I know about the Mostly DIY RF boards and kits but as the boards are out of stock I thought I've see if I could get boards made myself.

I found Craig Weston, VE3CBW, has kindly drawn up a design in KiCAD and shared it publicly. It opens up just fine in KiCad. He has a blog post here.

Craig has done a wonderful job of laying out the board in a logical way.

To get a board made I chose PCBWay, who I've used in the past. I followed their instructions on exporting the Gerber files. There are layers for the copper, hole drilling, solder mask and text - a bit daunting but I just did what they said and as you can see it worked just fine:

I've now populated the board and it works nicely.

The instructions on exporting the required files from KiCad are for an older version but I muddled through and made a zip of all the output files which was uploaded to PCBWay. I can see that they make a plugin for KiCad that does it all and I plan to try that next time. Here's what I zipped and sent. Not sure if everything is required but there were no complaints.

I ordered 10 boards for US$15.60 including postage on 6th December and they arrived on 23rd December. I chose the slowest postal shipping - you can pay much more for a courier if you need it faster.

My thanks to Craig. I would like to comment on his blog but it requires a login to something and I haven't figured out how to get through that so if you read this - thanks! Craig has a fascinating blog and a YouTube channel.

Local ham catchup including Peter, VK3YE

Yesterday, in a Melbourne park, I had the pleasure of a catch up with a bunch of old friends. Ham Radio Home brew hero, Peter, VK3YE, was there and of course he set up a squid pole and was soon making contacts on 10m FT8 and SSB.

Peter inspires me in a number of ways - home brew construction and getting out and participating on air.

His portable gear is satisfyingly minimal and shows beautiful wear and tear from regular use. For FT8 he uses an Android phone with a simple home made coupler.

Here's Peter's wonderfully worn FT817 and the famous home brew L Match:

It was great to catch up with everyone and I took the opportunity to quiz Peter on what I should do about my latest home brew amplifier which is operating with great efficiency as a 150kHz oscillator.

Tech news spot on ABC Radio

Nightlife Tech Guru Peter Marks, a software developer and technology commentator from Access Informatics, joined Philip Clark on Nightlife to discuss the latest news in technology. This week: Apple Intelligence launched in Australia. The way we search is about to change profoundly, and there are new scams to watch for this Christmas. 

https://www.abc.net.au/listen/programs/nightlife/tech-talk-with-peter-marks/104738420 

MeSQUAREs alternative - 1/32" board

MeSQUAREs are excellent. I've purchased them from QRPme in the past and used them with great success. I get through them very quickly and find it a bit unfortunate that the postage costs more than the product. 

I've been looking at ways to do copper board prototyping in various ways including recently cutting circular pads.

Cutting copper board is difficult. It can be done with a hacksaw or Dremel but it's a tedious process and it's very hard to make small bits of board. The obvious answer is to use "tin snips" to cut the board but I find it splinters badly. 

Recently I discovered 1/32 inch copper board. Kevin, VK2KB, kindly sent me a few boards and I ordered some via eBay. It seems to be used for some sort of craft activity. It cuts quite easily:

I've been able to quickly manufacture a collection of useful little squares:

As an experiment, I've built a simple, one way, 10dB gain, Termination Insensitive Amplifier as described by Wes Hayward, W7ZOI, and Bob Kopski, K3NHI:

It works nicely! The copper does curl a bit when cut but I found it can be superglued down quite easily. I used a weight on the long power rail shown above.

Here's how I hold components while soldering the first lead:

My second attempt at a TIA is much more compact:

TIAs are very useful and I thought it might be nice to get some PCBs for them. I have bought from MostlyDIYRF in the past but the shipping US->Australia is extravagant. Looking around I found that Craig Weston has done a PCB design in KiCAD and generously shared it here.

Tech news spot on ABC Radio

On ABC Radio Nightlife I talked about Australian Government's efforts to reign anti-competitive actions by multi-national tech giants. Also age verification approaches, disruption of Uber, AI at the Commonwealth bank and how to kill an Ear-worm.

https://www.abc.net.au/listen/programs/nightlife/tech-talk-with-peter-marks/104680640