Mellotronists

>Why do you want to do this? It works pretty well unless you have a
>weak pulse - in which case Martin can provide a stronger pulse
>tape - and if it misses going one way it usually gets it on the way
>back.

It does work, but it's somewhat complex and relies on analog circuitry to 
do its dirty work and thinking.  Every time you hit a station button you 
hold your breath.  :-)

Ken M's Mark II cycling was knocked out of whack when he installed new 
tapes.  The tapes now stop well short of the pulse mark, so the inching 
part of the cycling takes a lot longer than it should.  Jerry's Mark I 
Julia cycles very quickly in comparison, as little as 3 seconds with an 
average of about 5-7 seconds, because it stops fairly close to the pulse 
and doesn't have so far to inch along.  Ken's Mark II is probably 15-30 
seconds or so.  I am sure Ken's Mark II can be adjusted to correct this.

Interesting:  I noticed that the higher the station number the more the 
inching, and that applied to Ken's Mark II and to Jerry's Mark I.  The 
motor seems to go into inching mode further away from the pulse the higher 
the station number.  So there's some kind of slop in there.  Fortunately 
for Jerry that extra inching is almost negligible.  Oh well, Ken.  :-)

Anyway...If a new mechanism were to be designed, it could still use the 
pulse tape, but I'm more than certain the station control would be done 
with a microprocessor and not use resistors in series, a draining capacitor 
(Jerry---I don't recall what kind of circuit you said that was), and 
machine hunt-and-peck.  :-)

I will have to say that it *is* clever.  Did you know that if you disable 
the pulse tape and it did go past where it thought it was to go it'd 
reverse and try to find its mark?  How it knows that I don't know---would 
love to see the schem & theory.

...kl...M400 #805 - one station, no waiting

* Ken Leonard - Web Table of Contents:  http://www.kleonard.com
* Get Outdoors New England:  http://www.GONewEngland.org