Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "d1camero" <a8723@...> wrote:
>
> Hi all,  I am building a tube guitar amp PCB.  It requires heavy
> copper on thick boards.  I would like to use 1/8" boards, but cannot
> find any locally.  Anyways, here are my plans:
> 
> Toner transfer method using Phoenix TTS paper (all I can get here in
> Canada).  Then I plan to etch using MG Chemicals Sodium Persulphate
> and hand agitation.
> 
> Is this reasonable for this thick of copper, or should I try a
> different method.  Any hints, tips, or related sites would be 
appreciated!
> 
> thanks
> Don
>

You could probably get this to work, but for thick through hole parts 
in tube amps, I believe the reason for 1/8" board is stability in the 
face of higher heat levels.  Single sided is not going to cut it 
though, as one thing that helps is having plated through holes to 
hold the part mechanically in place.  Supposedly, you should use 
double sided just to have a solid metal eyelet holding the part to 
the pcb.  This is even if traces only run on one side.  So for a high 
quality tube amp built on a pcb, you should farm out the pcb 
construction for the plated through holes.

Read this for more info:

http://www.aikenamps.com/PCBorPTP.htm

If you're going to homebrew you might want to try eyelets through a 
plain (no copper) pcb.  Here's more info:

http://www.eham.net/articles/16053

Although using eyelets seems rather low tech, it looks like it is 
considered a high quality (though labor intensive) construction 
technique.  Old Fender amps in the 50s and 60s (preCBS) used eyelets 
and apparently they are still reliable.

Cheers,
Don