Can anyone tell me what this is?

[Dennis Markham]

Greg, I don't "KNOW" that what I'm about to write is 100% factual or yet another example of lore handed down.  Despite my lack of supporting evidence here's how I understand the body designs.

The evolution of the design of the D1 (oval) body originated with the desk stand phone (candle stick).  Once there was a conversion to the cradle type handset the round based B1's were only manufactured for about two years. Perhaps to use up remaining stock from the sticks? I don't know.  The D1 body was then elongated to mirror the the shape of the handset.  The D1 has a slightly lower profile than the earlier B1.  I do not own an A1 but believe this may have been the link between the stick and the B1 body telephone.  The cradle shaft is somewhat higher than the B1 and later D1 body phones.

You are correct, a 102 is a side-tone set, connected with a 3-conductor desk stand cord (from phone to a side-tone subscriber set) regardless of body style.

The 202 is an anti side-tone set connected by a 4 conductor desk stand cord to a anti side-tone subscriber set, regardless of body style.

[Jim Stettler]

The circuit makes it 102 or 202. The Round base (B1) came out before the oval base (D1). My understanding is they went to the oval base to help keep the phone from sliding as much during dialing.

The A-1 is the transition between the stick and the B1. I have been told that back in the day some collectors converted A1's back into sticks. 

I have a bsp referance regarding using friction pads on the D-1 in case sliding is a problem. I have also seen NOS replacement cloth that has marking for friction pad locations. So if you ever wondered if the friction pads were supposed to be on your D1. They were (if needed).
Jim S.

[Phonesrfun]

So if you have a round base hooked up to anti-sidetone, that makes it a 202?  And vice-versa, oval base hooked up to sidetone makes it a 102?  Other than anti-sidetone or pro-sidetone or don't-care-either-way sidetone, why did they make round and oval bases?  Were they made in different years?

Briny:

Yes, yes, and yes.  The round base B1 base preceeded the oval (Elliptical) D1 base by a few years.  The oval base was designed to help with stability.  The 102 and 202 designations are purely the circuit, and are not necessarily a function of the round or oval base, as the urban ledgend spreaders on e-Bay might have you believe.  It seems plausible, since the overall design is different, but simply is not the case.

Also, about the same time as the oval base wasrolling out, they also began rolling out the antisidetone circuit, which helps muddy the water.  Probably most round base phones were wired as 102's and most elliptical bases were wired as 202's

By the way, Andy, there is a circuit that you can use that simply uses a resistor and a capacitor in place of a network that keeps DC out of the receiver circuit.  On today's lines, you won't notice much difference, and with a little imagination, you can probably readily fit it in the spacesaver body.  It will be a sidetone circuit, and does not use an inductor.  If you are interested, please holler.  It is very simple to construct out of parts that are readily available from Radio Shack and only for a couple bucks.

-Bill Geurts

[Andy FitzGibbon]

Bill,
Yes, that sounds interesting.  I sent you an email.
Thanks!
Andy

[Bill]

Hi, I have seen 2 versions of these, as Bill described and in some Swedish Ericsson phones.
I have to guess about the black cylinder.

The black cylinder is probably a capacitor to keep the DC line voltage out of the buzzer.

Bill