Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "ednspace" <ed@c...> wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "Bob" <spoothammer@h...> wrote:
> > 
> > Does Datak mention anything about using a "sunlamp"...something 
> with 
> > some UV spectrum in it? 
> 
> Thanks for the reply Bob,
> 
> Could be part of the problem, I started with a standard sort of Grow-
> lite by GE but did not know how much if any UV was in it, so switched 
> to the Photoflood bulb.  

The photoflood is going to be optimized for balanced visible light.
The growlite will be optimized for more UV light, which plants need to
grow. I used a 150W growlite floodlamp.

> I may try another negative, right now I have very little black in 
> mine because the circuit is sitting in a ground plane, traces only 
> slightly seperated.  Possibly I can tell whats going on with wider 
> space between light and dark areas of the negative.

How are you holding the negative onto the board? Plexi or glass? How
thick? I'm not certain, but I think Plexiglass may block more UV than
glass, at least compared to cheap thin glass anyway.

Steve