Hey guys, another question. I searched the form before asking. There was one discussion about 415B tie line cards but it never went into how to wire them. One of the posters suggesting googling ITT 415 KTU for a service manual, but maybe in the years since the original post it was taken down because I can't find anything.

Right now I have a few 415B cards and a 3 open slots on my 620A2 KSU (changed it from a 4 line to 5 since I have the space, and many of the phones are 5 line not 4) so I figure why not use them up for fun.

I know they are designed to call to a distant location instead of inside of the same building, but just for fun would it be possible to make it call another line on the KSU locally when a key is pressed? If so how would I wire that?

Thanks

John

Wire each card to a button on a set the way you would with any line card. The wire the CO T/R from one card to the other. When the first unit goes off hook, the second one will ring.

It was not uncommon to wire up two of those units inside a large plant to provide hot line communication from one location to another.

Sam

Thanks I'll give it a try.

check out http://doc.telephonecollectors.info/dm/KSP415-00A_I1_%20K415_KTU_TieLineCircuit.pdf (found via Google)

hope you've already found https://www.telephonecollectors.info/ - a great site for us old tinkerers!