WE 688C Subset - what is this?

[RotarDad]

Just saw this.  Looks like a payphone 685A subset (net + ringer), but it has some added circuitry.  Any idea on this?

https://www.ebay.com/itm/223292837655

[Ktownphoneco]

I believe it was one of the subsets used with the W.E. type 3211 telephones (211 with the touch tone dial).   Try a Google search of the TCI Library for "688C".

Jeff Lamb

[compubit]

Anyone have ideas on what the triangular circuit is for? It looks almost like a separate network (transformer, capacitors and resistors...).

Jim

[RB]

Not sure, but that board looks kinda like an amplifier?
prob not, but it has a transistor, and that power transformer???
could be a switch circuit of some kind?
just my humble opinion.

[RotarDad]

Ok, the TCI library search did retrieve a 688C (non-dial) and 690C(dial) subscriber set (thank you, Jeff).  Here's the schematic in 3 sections. It shows a buzzer and an amplifier, but there is no explanation of what this unit was used for.

 

[poplar1]

The amplifier may be for a headset, used with a 6026-type key (4A Key). There is a desk telephone set with headset jack (514/2514) with similar amplifier.

http://paul-f.com/we514.htm

[Babybearjs]

just to let you guys all know... the 3211 is the autovon version of the 2211. and yes, the added circuitry is for the headset adapter... but I don't understand why you would use a headset with is style phone?

[Jim Stettler]

just to let you guys all know... the 3211 is the autovon version of the 2211. and yes, the added circuitry is for the headset adapter... but I don't understand why you would use a headset with is style phone?

I used to own a black 2211. 
As far as a headset goes. The same use  as any other time.  If you are always on the phone, a headset makes sense. If you are transcribing a headset makes sense. for added security, a modified headset may be used? ect.
The 211 series are very small phones. they don't use flat space. If the program is outgrowing it space , you may need to make use of all available space.
Jim S.

[dc4code]

The inside of one of my WE500's looks like this. At least the network does.

[RotarDad]

Dylan - you are correct.  These subsets use the 500-spec network (425B or later 425E, I believe] and C4A ringer.