[GreenKeys] I bought one like this on ebay

[Paul Wills (CKT&T)]

It's part of a Western Electric selective calling system generally used 
by railroads but also found in other places.

Basically it takes 17 polarity reversals broken into three strings of 
reversals.  The code wheel steps up with each reversal.  If there's a 
pin in place during the pause between strings, the wheel stays in 
place.  Otherwise, it returns to the home position.  The wheel with the 
pins set to match the strings of pulses eventually winds up and closes a 
contact to ring a bell.  At least that's the 60 second explanation.

The one in the picture is interesting in that it has four additional 
contacts that can be selected.

PDW

On 2/22/2022 5:28 PM, steve bennett via GreenKeys wrote:
> I bought one like this on ebay.
> What is it and what can I use it for?
>
> 1746 GENERAL COMMUNICATIONS PRODUCTS 60BC SELECTOR | eBay 
> <https://www.ebay.com/itm/294299466895?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818142401%26meid%3D8d28f6dfcfa14183b5abc7ab67d57d0e%26pid%3D101124%26rk%3D4%26rkt%3D4%26sd%3D403459165008%26itm%3D294299466895%26pmt%3D0%26noa%3D1%26pg%3D2563228%26algv%3DDefaultOrganicWeb%26brand%3DStromberg&_trksid=p2563228.c101124.m2109>
>
> $59.99 	
>
> 	
>
>
>     1746 GENERAL COMMUNICATIONS PRODUCTS 60BC SELECTOR | eBay
>
> <p>PREVIOUSLY OWNED 60BC TELEPHONE SELECTOR</p> <p>GREAT COLLECTOR 
> PIECE!</p> <p>PLEASE REFER TO PICTURES</p> ...
>
> <https://www.ebay.com/itm/294299466895?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818142401%26meid%3D8d28f6dfcfa14183b5abc7ab67d57d0e%26pid%3D101124%26rk%3D4%26rkt%3D4%26sd%3D403459165008%26itm%3D294299466895%26pmt%3D0%26noa%3D1%26pg%3D2563228%26algv%3DDefaultOrganicWeb%26brand%3DStromberg&_trksid=p2563228.c101124.m2109>
>
>
>
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