[GreenKeys] WW-II Model 15 curiosity.

[epvgk at limpoc.com]

On Sat, Jan 07, 2012 at 07:06:03PM -0600, Jim Haynes wrote:
> 
> Just when you think you have it all figured out something comes along to
> show you that you don't.
> 
> With Model 15s, I'm aware of holding magnet selectors where the selector
> coils can be connected in parallel for 60ma operation or in series for
> 20ma operation.  But I thought all the pulling magnet selector models
> always had the magnets wired in series for 60ma operation.  The parts
> book shows the magnet is 177M, 105 ohms, and I just measured a few of
> them and found them all to have about that much resistance.
> 
> I was just cleaning up a WW-II Model 15 cover and there is a red decal on
> the copyholder.  It says to check the magnet wiring before placing the
> unit in service, shows wiring diagrams of series and parallel connections,
> says 1020 ohms next to each.  Shows parallel connection for 60ma and
> series for 20ma and cites MWO SIG 82.  And the picture shows the round
> selector magnet coils typical of pulling magnet selectors, not the holding
> magnet kind that has more squarish coils.


I have a Model 14 keyboard typing reperf, which has the same red decal on the
copyholder (1020 ohm, etc... ) However, someone's replaced the selector magnet 
on mine with a homemade one with two handwound looking coils, each of which 
measures 3600 ohms(!) and they're wired in parallel for about 1800 ohms.  
The range finder is stamped "HM", i assume for "Holding Magnet." 

I'm pretty sure this homemade magnet isn't anything like what's supposed to 
be there. I can sometimes get it to sort of work at around 25mA with minute 
tweaking of spring tension, but never very well. 

Anyone have a correct selector magnet setup for one of these beasts? 

eric