I can’t believe it!

Working on various vintage reproduction projects, an irritant has been the look of the modern PCB stock we have available today.  Modern PCB stock is made with a different process compared to decades ago and as a result both the color and texture are different enough to make it a dead giveaway that your reproduction is just that.   Not that we should try to deceive – we do have a responsibility to ensure that future collectors are not fooled.  But for my own purposes, especially for projects where the boards will be visible, that modern stock just ruins the whole aesthetic.  Here’s what I’m talking about:

On the left is a new Mark-8 PCB produced using current PCB material.  On the right is an original Mark-8 board fabbed using the old process.  You can see there is a distinct difference in color – a kind of ‘fluorescence’ to the vintage board on the right.  Further, when you get up close and look at the new board, the product is very smooth – vintage stock had a grain to it that was very apparent.   No amount of dye or other tricks can correct this.  Further, vintage PCB stock often has manufacturer ‘stamping’ on it that identifies where it was produced.  My Mark-8 boards have NVF or Tc stamped all over them – indicating in the latter case that they were made by New Jersey fabhouse Techniques.

Unfortunately for years, the stuff on the left was the best I could do.  Until two weeks ago, that is.  I had been constantly searching ebay for ‘vintage PCB’ or ‘vintage copper clad’, the former yielding nothing and the latter yielding pots and pans.  However, one day I decided to try searching via Google.  I don’t know why but Google often finds things ebay itself can’t find.  To my amazement, up came an auction for vintage PCB stock!  And not just unknown vintage either!  Actual dated stock from 1973!!!!!

I couldn’t believe my eyes.  I know this seems like a trivial thing but to me this is huge.  With actual 1973 board stock, I can make something that is virtually indistinguishable from the original!  Naturally I ordered everything the guy had.  Two weeks later, here it was:

Incredible!  I mean, I’d expected to find something vintage-ish with enough searching.  But actual new-in-bag with verifiable date of production?  Crazy!!  These boards have survived untouched since the days of President Nixon.  They were around for the last days of the Vietnam War, Watergate, the fall of the Soviet Union.. wow!  There can’t be too many of these still lying around out there, but I’m glad I kept the faith that there had to be at least some!

The boards are 0.03″ thick, rather than the usual 0.06″.  But actually, that’s okay.  Because they are single sided, if I wanted to make a Mark-8 board, which is double-sided, I can just make the two sides separately and then laminate them together.  I’ve made boards from double sided 0.06″ stock.. it’s tricky.

I am currently working on building a SWTPC PPG joystick.  I had already made one from the modern PCB stock – let’s see what it looks like with vintage!  I almost feel kinda guilty opening these packages that have been untouched for four decades…

I used the usual toner transfer process to get my resist pattern onto the board.  It went down pretty much the same as with modern – however, perhaps owing to the thinness of the substrate, the iron did manage to melt a sort of checkerboard pattern into part of it.   Whoops!  Anyway, next I cut it (easy, since it’s only 0.03″ thick!) and etch.  Here are the results.  First, we’ll compare it to my modern board stock:

Note: I etched a second piece of the vintage stock completely so I could sandwich it to the first piece, to give an idea of the color with the board at 0.06″ thickness.  Above is the result, below is a TVT board I made using modern stock.  Interestingly the scanner kind of distorts the color a bit, but you can still see a difference.  In real life, the modern board is a more brown/yellow color and stands out pretty dramatically vs. the vintage board stock.

Here is a scan of the joystick board next to an original Mark-8 board:

Bit of a difference in darkness for sure.  In person, the Mark-8 board doesn’t look that dark and in fact looks much closer to the NOS vintage stock.  And it should, since they both were made by Techniques.  Know how I know?  Check it out:

That, my friends, is Techniques’ mark.  Same marks that appear on my original Mark-8 boards!  Different color — the ones on my Mark-8 boards are kind of red, but still.. very cool!  I can make brand new Mark-8 boards that nonetheless have the old Tc stampings on them!!

Anyway, the lesson here is patience and persistence pay off.  I knew it had to be out there and just kept looking, for years.  There is probably more, maybe even some double-sided or 0.06″ thickness.  It’s definitely out there!  Now I’m in a pickle.. do I leave my TVT as it is or go the last mile and remake the boards from vintage stock?  Hmmmm… 🙂