On longer loops from the central office or wherever you got your service
from.  I'm guessing the default order for a Bell System provided machine
was to include one. The majority of the machines I've come in contact
with had them. If you look at the wiring diagram package for 28
printer's LESU, you'll find the vast majority of the configurations
include the line relay.

(Those wishing to remove the line relay from a 28 KSR/RO (for the
minimalist configuration) would find 2874WD and 2875WD useful)


On 1/15/2025 12:06 PM, steve bennett via GreenKeys wrote:
> John,
>
>  In the video Mark mentions polar relay but he says it optional.
> He does not explain.
> When would you need to use it?
>
> Thanks,
> -Steve
>
> On Wednesday, January 15, 2025 at 12:21:55 PM EST, John, W9DDD
> <[email protected]> wrote:
>
>
> That is the bracket with socket for a line (polar) relay. Relay not there.
>
>
> On 1/15/2025 10:51 AM, steve bennett via GreenKeys wrote:
>> GKs,
>>
>>  What is the purpose of this relay shown in the Curious Mark video?
>> Inline image
>>
>> -Steve
>>
>>
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>
> --
> ---
> ----
> The above comments or recommendations are SWAG. Use at your own risk.
>
> John, W9DDD
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