[GreenKeys] Rumination

Dave Horsfall dave at horsfall.org
Fri Aug 28 22:47:17 EDT 2015


On Sun, 23 Aug 2015, Richard Knoppow wrote:

> First crystal set was built with my dad who I think took a course in 
> electronics.  Built on a board with hand would coils (on tubes from 
> paper towles I think).  Only thing modern was the crystal, not a cat's 
> whisker type. We strung a wire from the garage roof to an upstairs 
> porch.  I heard lots of stations around Detroit and listened to the Lone 
> Ranger on it.  I passed up a couple of old (maybe) loose couplers with 
> detectors at the TRW swap meet a few years ago and have regretted it 
> since.

First set I built, I proudly presented to my Science teacher.

He asked: where's the diode?

I pointed towards the 1N914.

It's motor-boating!  Where's the coil?

Err, it was a huge lump of wire that I threw together...  It was thus that 
I learned this "resonance" thing.

One over two pi root LC, equals resonant frequency.

Thank you, Mr Philips, wherever you are.

-- 
Dave Horsfall DTM (VK2KFU)  "Those who don't understand security will suffer."
 Concerned about shark attacks?  Then don't go swimming in their food bowl...


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