[GreenKeys] Harmonic Analyzer -- Fourier analysis/synthesis using gears, cams, levers, springs, and the kitchen sinc

Fri Jun 15 05:37:43 EDT 2018

That’s why I like the Differential Analyzer. It demonstrations integration
in real time

http://www.cs.man.ac.uk/~chl/hartree.html

(sorry the videos are flash and must be manually started).

I also worked at Bidston Observatory where we had two Tidal Prediction
Computers which we operated for special occasions. I found some info about
them here:-

Again a wonderful physical demonstration of simulation of waves from
physical parameters.

Dave

G4UGM (& EA7KAE)

From: greenkeys-bounces at mailman.qth.net <greenkeys-bounces at mailman.qth.net>
On Behalf Of Bruce Gentry
Sent: 15 June 2018 00:55
To: greenkeys at mailman.qth.net
Subject: Re: [GreenKeys] Harmonic Analyzer -- Fourier analysis/synthesis
using gears, cams, levers, springs, and the kitchen sinc

So many people, especially the young, feel mechanical engineering is
obsolete and useless. It has the great advantage of demonstrating principles
and operations in a form that is tangable and can be easily reviewed
repeatedly until it is understood. With that knowledgeï¿½ firmly
established, there is some expectation of the results, and errors in
converting the task to digital are more likely to be discovered.ï¿½ Going
directly to digital design in the abstract first without a solid basis is
not always wise.ï¿½ It is very unfortunateï¿½ the early IBM MARK series and
other mechanical "computers" have been lost to the ages, I doubt even the
drawings for them still exist. Forï¿½ something quite complex and
fascinating,ï¿½ take the covers off a Marchant or Friden mechanical four
function calculator and watch it in operation.

ï¿½ï¿½ï¿½ Bruce Gentry, KA2IVY

On 6/14/18 5:24 PM, Jordan Spencer Cunningham wrote:

I love engineerguy. I wish he made more videos.

These machines remind me of Babbage's Difference Engines and Analytical
Engine, which were designed in the 19th century but never actually built
until recently (that is, Difference Engine 2 was built within the last few
decades for the first time, though the Analytical Engine is still just on
paper). 

https://www.youtube.com/watch?v=be1EM3gQkAY

https://youtu.be/BlbQsKpq3Ak

And I thought teletypes or my Burroughs mechanical adding machine were
complicated!

It's incredible what people were able to do with mechanical or
electromechanical machines (teletypes included). It took some absolutely
genius engineering.

--Jordan

On Thu, Jun 14, 2018 at 3:52 AM, Paul Heller <paul0926 at comcast.net
<mailto:paul0926 at comcast.net> > wrote:

Wow Gil. That was something. That machine offers a full semester of high
school physics: levers, gears, springs.ï¿½ And the fact that the pen
orientation affects the way the plot is drawn (near the end of the
operations video) certainly must be college level physics! 

Thanks for sharing. Iï¿½ve watched his other videos in the past and they are
all interesting to me.

Paul
W2TTY

ITTY: HTTP://INTERNET-TTY.NET:8000/ITTY
AUTOSTART: HTTP://INTERNET-TTY.NET:8030/AUTOSTART
EUROPE: HTTP://INTERNET-TTY.NET:8040/EUROPE

On Jun 14, 2018, at 6:43 AM, Gil Smith <gil at baudot.net
<mailto:gil at baudot.net> > wrote:

>From a bit of dsp research I have been doing lately I ran across this
amazing machine designed in the late 1800s.ï¿½ There are more videos, but
these two short ones show the main points:

"Synthesis" is the combination of sine/cosine waves in a linear system to
generate a specific waveform:

https://www.youtube.com/watch?annotation_id=annotation_2259796885
<https://www.youtube.com/watch?annotation_id=annotation_2259796885&feature=i
v&src_vid=NAsM30MAHLg&v=8KmVDxkia_w>
&feature=iv&src_vid=NAsM30MAHLg&v=8KmVDxkia_w

"Analysis" is the decomposition of a waveform into the frequency-domain (eg:
spectrum analyzer):

https://www.youtube.com/watch?annotation_id=annotation_2259796885
<https://www.youtube.com/watch?annotation_id=annotation_2259796885&feature=i
v&src_vid=NAsM30MAHLg&v=8KmVDxkia_w>
&feature=iv&src_vid=NAsM30MAHLg&v=8KmVDxkia_w

A pretty cool bit of mechanical engineering indeed.

gil

gil smith, AF7EZ
greenkeys moderator
gil at baudot.net <mailto:gil at baudot.net> 

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