Print Circuit Boards from Magazines - why are they wrong? I need your help.

I am finding that the PC boards from popular electronics, Radio electronics, etc are not transferable from the magazine to an actual PC board. If there is anyone out there that can help me, please comment in the comment section. I would appreciate it. Thanks in advance.

[@TrevorsBench]

Back then, it was the intention that people would photocopy the image onto transparency film to use as a template. Then you could flip it to put the toner side of the transparency down close to a resist treated copper clad board. That way the image would be crisper. You could buy copper clad boards with both positive and negative resist applied and would pick accordingly to what image was supplied.
Many times people would have the transparency the wrong side down and would etch a reversed board.

[@VinceWaldon]

My thinking as well.. these designs and publications come from an era that pre-dates anyone having a laser printer and doing "toner transfer".... we all took the artwork to a litho shop and had them do the negative. They would adjust the size, if needed based on the dimensions given, mirror the artwork if needed (and if we were picky to have the emulsion face the photosensitive coating) and also turn positive (white lines) into negative lines (black) as required. These days a photo-editing program like Gimp or Photoshop can do the adjusting, mirroring (if needed), and contrast reversal (if needed). You can use the same tool to touch up blotchy traces that aren't completely dark in the magazine, like the ones we saw in the artwork used for the 30W stereo amp project. :)

[@MrElectrowhiz]

Most of the photos in the magazines at that time was shot on slide film which is a positive. No negatives comes from slide film. Maybe there is a program that can invert the color and the direction that you can print from. I had a friend that used to shoot pictures f0r magazines and this is what he told me. I also used to shoot slide film a lot.

[@bettinaneumryr]

Ah-ha ... real good info. I also was a bit into photography in the 90's. As an aside Kodak used to have 25 ASA film at one time. It was such a nice film. Thanks for your comment, I really appreciate the information. Cheers!

[@feraloid]

I was around "back in the day", but can only speculate. There was no method I know of for directly doing a PCB from a magazine image. Perhaps some obscure photo-resist method, but most require strong lights and that would get bleed-through from the printing on the back of the page. It could have been done with a photographic copy camera...but who actually would do that? It's easy enough to flip, reverse or fix inconsistent density in a program like GIMP or Photoshop. I'd be happy to do it if you could get the images to me, perhaps Google Drive, Dropbox, etc.

[@bettinaneumryr]

Thanks for the quick reply. I can always do the photo resist method for some easily enough. I was going to try using GIMP like you suggested. I have it on my computer so later today I will experiment with your suggestion of flipping and density. Thank you for your comment. I am learning more and more about the history of the PC boards from magazines

[@gillywild]

I’m assuming that you mean they are shown from the wrong side? As if looking through the board from the top. I expect they expected the reader to have bought the boards from them and the image was an aid for construction? Regardless, you can flip the image in any drawing software and also swap black and white if necessary. It is also a good idea to check the hole pitch at this point. I can confirm there were photo etch films available in the 90s but laser printers came later, though you could have done toner transfer with a photocopier if you had access to one.

[@SS-mj2mq]

Use see-through clear projector paper draw the circuit out tracing over the the drawing out traces with a black or blue or red color marker fine tip. Then use a LaserJet printer and print it out make sure it's flipped to the other side before printing it out and then iron it to the copper clad PCB board and then use etching solution to remove all the copper the edging solution will not remove the LaserJet gel print it will only remove the copper then you can take some sandpaper and sand off the laser gel printed excess Inc. If you would like I can make you a video on how to do it and you can watch me do it 😀

[@---mafon]

потому что у тебя посадочные места не под dip микросхемы а под smd, это другой тип корпуса

[@---mafon]

точнее под soic или типа того