The "Radio Times" Amplifier

For the benefit of dx readers, the Radio Times is the UK TV listings magazine which traces its history back to the BBC's original publication. It is distinguished by covering Radio schedules (as well as TV - hence the name) but, just like the other UK listings magazines, it is now full of advertising and editorial nonsense aimed at those who worship the "idiot's lantern" in the corner of the room. I will get round to cancelling my subscription one day!

Regular readers of this blog will remember that I'm a sucker for making printed circuit boards (even when Ugly or similar methods are as good or better). Unfortunately, I used my last sheet of Epson SO41126 Photo Paper in making the S9 Generator. That meant I had to find a new medium for my toner transfer process...

First stop was made during the weekly grocery shop at Sainsbury's new Urmston Store, where I splashed out on a pack of 20 sheets branded "Howard Smith Paper". I should have realized things wouldn't turn out too well when the packaging boasted "environmental glossy photo paper" - the word "mental" was there for all to see!

Here's the "mental" paper (along with the original Epson favourite and some cheapskate paper from Tesco's still to be evaluated)...

Now - I've got nothing against environmental initiatives in principle, but I'm not prepared to substitute concern for quality with concern for the environment (too many disappointments with fair trade coffee, in which the feel-good factor of trading fairly never quite took away the taste).

I don't doubt that the environmental photo paper is great for its intended purpose of bearing photo images - but I found it pretty useless as a toner transfer medium for making PCBs. It was way too thick (at 260 gsm) and - to be fair - it wasn't until I tried it that I realized this is an important parameter for the toner transfer method. Thick card is an unwanted thermal insulator!

Imagine my delight (as a self-confessed cheapskate) when I stumbled upon Alberto's website, where he describes how it is possible to use paper from "junk mail" promotional material, magazines etc as the medium for toner transfer! I just had to try it...

I decided to knock up a PCB for the PA I'd used in the h/b WSPR rig purely to experiment with Alberto's process. I chose two experimental papers; the front page of a recent Radio Times and a flier from Asda.

Here's the toner image on the Radio Times cover...

Never (since the Yellow Pages adverts) has James Nesbitt been so useful!

I also tried the Asda flier (perhaps the fact that I alighted on the wine page was Freudian HI HI)...

Again, for dx readers, Asda is a UK supermarket chain where I choose not to shop - 'nuf sed.

After getting the XYL's iron out, the attempted transfer onto the copper clad board of the toner depicted in the two photo's above yielded disappointing results...

• "Asda" was useless (why aren't I surprised?)
• "Radio Times" transferred the toner - but transferred a lot of other stuff too!

After a lot of work soaking and scratching with a pin between traces, I did generate a viable PCB using the Radio Times...

which, when populated and tested, became - of course - the "Radio Times" amplifier...

OK - so Alberto's "free" toner transfer process works - but it took WAY longer than the one hour he promises on his website. That is not to say that it is a bad idea - more experimentation may yield better results with the right kind of paper. Alberto was advocating "cheap" paper - the poorer the better - pity I don't seem to get fliers from Lidl.

I encourage readers to experiment with Alberto's ideas - for my part, I'm going to stick with glossy inkjet paper, despite the cost. I noticed on the web that Tesco have a fairly thin, very cheap paper in their "Value" range (which previously I recommended only for the spaghetti). I am going to give this a try and may report back - watch this space!

...-.- de m0xpd