[GreenKeys] Pulling vs Holding selector magnets

[John, W9DDD]

The 14s with the switch or terminal strip had them mounted right up by 
the selector.  I can't remember where those would have been mounted on a 
15.  Maybe the two times I worked on a 15 they both had pulling magnets? 
(once in 1965 and once 2 years ago)


On 1/20/2025 8:51 AM, Jim Haynes wrote:
> And some holding magnet macbines will have a toggle switch to
> make the coils connected series or parallel.
>
> The original reason for the holding magnet selector, and this comes from
> the mouth of the inventor, Walt Zenner, was to allow a lower loop voltage
> on the cord circuits of TWX switchboards.  Switchboard operators come
> in contact with the plugs on the cords, and 120V could be deadly if the
> operator had an unusually low resistance path to ground.  Holding magnet
> selectors allowed operation on 48V, which was also standard on voice
> switchboards and thus assumed to be safe enough.
>
>     ---
>
>     "Ya can argue all ya wanna, but it's dif'rent than it was."
>     "No it ain't! No it ain't!  But ya gotta know the territory."
>         Meredith Willson, The Music Man

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The above comments or recommendations are SWAG. Use at your own risk.

John, W9DDD