Has anyone seen one of these? SC 1553-WA-SPECIAL

[mdodds]

Hope I'm posting this in the right place!
I just bought a Stromberg Carlson wall phone from ebay:

www.ebay.com/itm/151636153214

The first phone I ever bought in the late 60's was one of these, so it's kind of a sentimental replacement
This one however has "SPECIAL" suffixed on the end of the model number and has a feature I haven't seen before. If you look carefully at the pics you will see a sticker on the handset cradle that says: To talk, press hook to left and up". There is a spring that holds the cradle to the right when you hang up and that puts the edge of the hook under a tang. In order to get the phone to go offhook you need to lift the handset, the pull the cradle to the left to release it. It was easy convert to regular operation by moving the spring so that it pulls the cradle to the left instead of the right.
I have inserted a picture of the hookswitch converted to regular operation so you can see the arrangement. but does anyone know what the purpose of this setup was, and was it common?


Thanks,
Mike

[unbeldi]

Yes, it was a very common feature.
This is called a two-step hookswitch and was used on party lines so that a subscriber could first check whether the line was already busy with another call by lifting the handset and listening for speech or dialing pulses.   If the line was clear the user actually took the telephone off-hook by performing the second switching step. This connected the transmitter and dial pulse contacts into the circuit.

S-C had various implementations of this feature. The 1200-series phones had a metal plate between the cradle ears that needed to be pressed down in the second step.

[mdodds]

Very cool! I just took the protective cover off the hook switch and could see that it closed one set of contacts in the locked, but handset lifted position and then closed the lower set in the unlocked position. Do you suppose that's what the "SPECIAL" in the model number means?

[unbeldi]

Very cool! I just took the protective cover off the hook switch and could see that it closed one set of contacts in the locked, but handset lifted position and then closed the lower set in the unlocked position. Do you suppose that's what the "SPECIAL" in the model number means?

That I don't know either to be certain, but it seems to coincide with my observations. I think I have seen the "SPECIAL" designation only on these wall phones.  I take that back, .... reviewing my picture archives, I have that designation also on some desk sets.

[paul-f]

Interesting marking.

SC T-1114 issue 2 (8/67) has the following listing:

2-1553-W

Same as 1553-W except telephone is equipped with two-step hookswitch.  This arrangement allows subscriber to monitor his own line to determine if it is busy, without connecting his transmitter to the line.

[mdodds]

And I just looked, rather than rely on memory and it is marked 2-1553-WA-SPECIAL. Hmmmm....now that you have found that the 2 designates the hookswitch, I wonder what the SPECIAL is? Maybe a frequency ringer?

[unbeldi]

The ringers are designated in the letter combinations after the model number.  This table contains a column for Stromberg-Carlson as well.  For example, a 50 Hz frequency ringer in a 1553 set would be designated  1553G.

Yours is a straight line ringer (Type 74 ?) for standard 20 Hz, indicated by the A.  The W indicates that is uses a self-compensating network, likely the 210640RA, which is similar to the 425B in the Western Electric 500 set.

[mdodds]

Wow.....the knowledge on this forum is amazing!
Now I have yet another question for the SC gurus. The dial doesn't seem to really mount on this phone. There is a horseshoe bracket that screws on the back of the dial with 2 shoulder screws. The shoulder screws drop into tangs on the phone to hold the bottom, and the the legs of the horseshoe sit on either side of the hookswitch bracket to prevent rotation. (At least that's how it looks to me). The problem is that one of those shoulder screws is missing. I think it's a #4, but not sure of the thread pitch. I have read several posts on here about dial screws where they mentioned a lot of the dial mounting screws are 4-36. However, none of those are shoulder screws. I have looked at various antique phone suppliers but haven't found any screws like this one. Any ideas on how to replace that screw?

Thanks for all the advice!

[unbeldi]

Wow.....the knowledge on this forum is amazing!
Now I have yet another question for the SC gurus. The dial doesn't seem to really mount on this phone. There is a horseshoe bracket that screws on the back of the dial with 2 shoulder screws. The shoulder screws drop into tangs on the phone to hold the bottom, and the the legs of the horseshoe sit on either side of the hookswitch bracket to prevent rotation. (At least that's how it looks to me). The problem is that one of those shoulder screws is missing. I think it's a #4, but not sure of the thread pitch. I have read several posts on here about dial screws where they mentioned a lot of the dial mounting screws are 4-36. However, none of those are shoulder screws. I have looked at various antique phone suppliers but haven't found any screws like this one. Any ideas on how to replace that screw?

Thanks for all the advice!

Yes, this is an interesting way to mount a dial. I have had at least one with a missing screw as well, but I don't recall what I did.  I think I may have had a parts phone to steal from.  Have not researched replacement options, IIRC.

[mdodds]

I may try a plain screw if I can find one and put a dollop of Loc-Tite on it and run it down to the proper depth. This isn't a museum quality phone, I'm going for functionality rather than authenticity A few battle scars on a 55 year old phone are to be expected.

[mdodds]

It's cleaned and re-assembled!
I will need to get a bit more aggressive on the handset when I get some Novus-2, but I'm happy with the result so far. Works fine, dials out and sounds good, rings with a vengeance. I would show the pics, but for some reason I'm getting the "failed security" problem. Pics were taken with the same cell phone cam as all the rest....go figure.