Homebrew PCBs

Hi John,

Yes!  I have Taggert's book, and I played around with weather fax's, but
AFTER CRT's were common.  what is FAX_Dhals?  A software package?

73's, 

Alan  KM6VV


crankorgan wrote:
> 
> Hi Alan,
>         I built a similar unit for receiving Radio Faxes
> from around the world VIA a shortwave radio. My unit used
> stepping motors from a floppy. That's 20 years ago! Here
> is a picture of the unit. I used some of Ralph Taggerts
> circuits and some of my own. I went on to design a circuit
> board that goes in the computer. I used FAX_Dhals.
> 
> see machine at:
> 
> http://crankorgan.com/kleinfax.JPG
> 
>                                      73s
> 
>                                     John
> 
> --- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Steve, John, list,
> >
> > check out Jon E's photo plotter:
> >
> >       http://www.artsci.wustl.edu/~jmelson/photoplot.html
> >
> > While it plots to film, I think you can get a few ideas from it.
> And
> > there are advantages if you can generate a good film, such as
> exposing
> > as many boards as you want from it.
> >
> > But yes, I DO like the concept of mechanical etching!  And the
> software
> > to do the isolation tool paths is very interesting to me
> (programmer).
> > As well as the controller it's self!
> >
> > I don't know the linear speed of Jon's photo plotter (perhaps it's
> that
> > the film is faster then the photo resist), but I'm surprised it
> couldn't
> > be made to work.  A laser out of an HP laser printer?  Then you'd
> need a
> > mirror to get the light over to the "pen lens" and down to the
> board.
> > Put the hole laser thing on the XY carriage?  Yeah, that could work!
> >
> > Perhaps we'll get a little more info on the HP, and someone can try
> some
> > experiments on exposing the resist on a board with a laser!  And who
> > cares if it takes a long time?  Controlling the size of the
> laser "dot"
> > on the board with an aperture would be the tough part.  I'm told
> that
> > commercial photo plotters use an aperture disk, which is a set of
> > "films" with an appropriate mask.
> >
> >
> > Alan  KM6VV
> >
> >
> > Steve Greenfield wrote:
> > >
> > > Yep, far too long to expose, and the problem of "blooming". UV
> > > laser, anyone?
> > >
> > > That sounds do-able! It would just require modifying a pen with
> one
> > > of those carbide point marking pens. I think you could probably
> > > just spray something like one coat of black fast drying laquer to
> > > scratch through.
> > >
> > > And one of the things I've always liked doing to boards I make is
> > > sign them. Couldn't do that when I made some with the vinyl
> cutter.
> > >
> > > So the only issues are paint that will scratch away cleanly and
> > > that it leaves a wide enough opening after etching.
> > >
> > > Steve Greenfield
> > >
> > > --- crankorgan <john@k...> wrote:
> > > > Hi,
> > > >    Nobody liked my light on a plotter idea. I was told the
> > > > light source would have to move too slow. The board would take
> > > > way to long. Ok, I use Mechanical Etching bits myself. But what
> > > > if you coated the whole board with resist. Then you put a sharp
> > > > point in the plotter. Have the plotter do isolation paths. Then
> > > > the board goes to the acid.
> > > >
> > > >                                           John