Beehive terminals

[Tony Duell]

> 
> On 12/31/2005 at 12:17 AM ard at p850ug1.demon.co.uk wrote:
> 
> >I thought the touch-tone keypad was 2 transistors, one for the column 
> >frequencies, one for the row frequencies. But I've never seen one.
> 
> No sir, it used only a single transistor.  Transistors were viewed as the

I stnad corrected. 

> least reliable part of a telephone and so usage was minimized.  Here's a
> schematic of the dial on one of them:

Interesting. I think the Post Office in England thought the same way at 
one point. They had a little transistorised signal tracer with a 4 (?) 
transsitor amplifier in it. Most of the amplifier was a potted module, 
but the transistors were mounted on top and soldered to pins sticking out 
of the potting compound so they could be replaced.


> I think WE doesn't get nearly enough credit for creating some really
> bulletproof designs.

I find it a great pity that now that transistors have become so cheap 
(particularly when in ICs), most people don't care how many are used, and 
most modern designs use far too many of them. It's amazing what could be 
done with 2 or 3 of the things, but those clever designs have been mostly 
forgotten.

-tony