Back in the 1970's when the electronics magazines provided full and half sizes photos of PCB's for the articles, I developed my own way of laying out PCB's. I photocopied the printed PCB full size, taped it onto the copper side of a single or double sided PB board, and used a Dremel with fine carbide drill bits to drill all the holes required.
Then I got a glass tube 3-4 inches long and slightly less than 1/4 inch diameter which I heated up in the middle with a blowtorch and when the glass was soft I would stretch it out to form a jet in between the two thicker sections and snapped it off leaving the glass tube with a 2-3 inch very slim section. I then poured a few drops of ladies nail polish into the tube and attached a rubber hose to the wider end of the glass tube. I prepared the board by removing the paper and sanding the copper side smooth and dust free. I then painted on all the traces using my home-made resist pen while gently blowing into the rubber hose. The whole process worked very well and I got to be good enough to run a line between the 0.1 inch IC pads.
After a long and careful comparison of my layout with that in the magazine - it was easy to correct any errors with a fine blade scraper, I etched the board using ammonium persulfate solution and a peristaltic pump to spray the etchant onto the board while it was in a plastic bowl. I have made boards up to 10 inches square with hundreds of holes this way. I even did some double sided boards this way. Modern boards with traces a fraction of a millimeter apart are out of reach for such hand-work.
Pharma Phil
---------- Original Message ----------
From: newxito <axta...@gmail.com>
Date: January 31, 2021 at 9:18 AM
I remember making an amplifier board using a felt pen in the early seventies.
--
You received this message because you are subscribed to the Google Groups "neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/3506112f-cf4d-4ec4-a624-46800dc4bdc1n%40googlegroups.com.
You received this message because you are subscribed to the Google Groups "neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/1044174140.5987355.1612110253371.JavaMail.open-xchange%40mtlgui03.
