Re: Update on my 7854 diagnostics project


 

Hi Ke-Fong-Lin,

I think Holger's solution of having them done by a PCB house was quite clever and it is inexpensive as well.

There are a lot of franchise stores that make inexpensive signs. A simple Google search I just made for "low cost signs" found thousands of them.
Most of these places might be surprised if you asked them if they could do holes or holes for individual keys.
But it might be worth searching for this capability since it will probably come in handy sooner or later.

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Holger L├╝bben
Sent: Saturday, May 23, 2020 8:07 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Update on my 7854 diagnostics project

Hi!

The trick is: In this case the front panel is also a pcb ;-)

This board is 0.8mm thick, white soldermask and black silk screen.
Here is a closeup of one of my red & white ones:

http://w140.com/tekwiki/images/7/77/P7001_program_overlay_card.jpg

If you look closely you can see the copper borders under the silkscreen

There a two downsides:
1) You can't get inner holes with sharp corners - usually you have to deal with 3mm corners. Thats the reason why my 7854 keyboard overlay card has a big hole per keyboard row - compared to individual holes for each key on the original card
2) I've tried a local pcb manufacturer and one of those cheap chinese ones and both reuqire at least one pad on the pcb. Thats the reason for the two pads on my panels.

But beside from that: They are great and look even better in real world.

If you want to have professional front panels you can also use services like www.schaeffer-ag.de. That's one of the local german ones, but I think you'll find such a company in every country.

Holger






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Dennis Tillman W7pF
TekScopes Moderator

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