Homebrew PCBs

Thanks guys.  I’ll tell you why I’m wondering about this.  Recently I missed, by inches, an auction on ebay that offered supposedly original SWTPC TV Typewriter boards.  Here’s a couple pictures of them:

 

http://s1381.photobucket.com/user/unclefalter/media/tvtboards2_zpssy81hx8b.jpg.html?sort=3 <http://s1381.photobucket.com/user/unclefalter/media/tvtboards2_zpssy81hx8b.jpg.html?sort=3&o=0> &o=0

 

http://s1381.photobucket.com/user/unclefalter/media/tvtboards5_zpsuo81gg5q.jpg.html?sort=3 <http://s1381.photobucket.com/user/unclefalter/media/tvtboards5_zpsuo81gg5q.jpg.html?sort=3&o=4> &o=4

 

http://s1381.photobucket.com/user/unclefalter/media/tvtboards2_zpssy81hx8b.jpg.html?sort=3&o=0

 

The thing I found weird with them was that they didn’t have any tinning on the copper side.  SWTPC usually did that on their commercial products (they did it on the boards for my TV Typewriter II).  So I thought hrm, maybe these were done by a hobbyist?  The silkscreening included one of the corner marks found in the magazine-published artwork for the boards, which I thought would be an odd thing to include.  So either they really are SWTPC boards, or somehow someone pulled off the silkscreening, or maybe they were replicated later.

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Wednesday, September 30, 2015 3:07 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] G-10 questions

 

  

On 30/09/2015 10:53, 'Dave G4UGM' dave.g4ugm@... [Homebrew_PCBs] 
wrote:
> When did etch resist pens come in? Pretty sure they were around in 1972.

I vaguely remember using a Decon Dalo pen around then (they are still 
available), but I could be wrong. I found that cellulose paint made 
easier to use by mixing it with thinners worked better, and was much 
cheaper.

Leon
-- 
Leon Heller
G1HSM



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