ECN Forum Forums General Topics of the Trade Voice - Data - Video Discussion Old phone block- wiring?

As I understand the history, it was almost exclusively the independents which used frequency selective ringing (it makes sense, therefore, that Automatic Electric had these tuned ringers).

Ma Bell had a 4-way party line arrangement with fully selective ringing. Two parties had their ringers connected tip-to-ground, two were ring-to-ground, and they all had a cold-cathode tube in series. By applying a suitable positive or negative bias the equipment could selectively ring each of the four phones individually.

Then by using a combination of single and double rings the same basic arrangement could make an 8-way party line, no longer with fully selective ringing but each phone would only ring for its own calls and those of one other party.

Some small SxS offices had a 10-way party line system with coded ringing in which the last digit of the number determined the ring cadence and whether ringing voltage was applied to ring or tip. For example, 4931=long, 4932=short-short, 4933=long-short, and so on, then 4936 through 4930 repeated the same codes on the other side of the line. People on a single-line would always have a number ending in 1.

We had distinctive ringing on an ISDN derived line, but not quite the same thing

MSN 1 - Short-short (UK/IRL standard ring)
MSN 2 - Long (European Style)
MSN 3 - short-short-short

The only time I heard distinctive ringing on an analogue line here thesedays is if you accidently hang up on a call that's on hold (i.e. during call waiting / if you press R)

You'll get short-short-short-short

Same ring applied if you set ringback when free. (camp on busy)
and RINGBACK + number will display on the CLID.

Another use for the 3rd (yellow) wire that I have come across is to power the little incandescent lamp that illuminated the dial on really old "princess" rotary dial phones.

The Telco provided a "wall wart" type transformer to feed the voltage (8 VAC?) over the yellow wire.

We just discussed that above.

-Hal

OOPS! Missed that...

If you hang up while there's a call on hold here you just get the normal double-ring (0.4 sec. on, 0.2 off, 0.4 on, 2.0 off).

We have a distinctive-ring service which provides a second number on the same line with single-burst ringing (1 sec. on, 2 secs. off). Unlike the old Bell CDO above though, the caller still hears the regular double-burst ringback.

Apparently those old Bell System CDOs would allow you to dial any of the numbers associated with a specific line, even if it was only single-party service. So if someone on a private line had 4931, so could still reach him with 4932, 4933 etc. and get the different cadences.

Multiple distinctive ringing undocumented and for free!

You all have been most helpful. While a bit late in the game, I thought I'd post a pic of the block. There are two in the pic; I opened the one on the left so you could see the insides.

Yup, just as ED said. That's a carbon protector, not a block. Those two 7/16 nuts on the left and right are the T&R phone line. The middle one is a ground for the protector. That should be a #14 from it to the electrical ground. Any other wires on that ground binding post- cut them off (unless its another #14 to the other protector, but I don't see that.)

If you are courious unscrew one of the carbons (the 1/2" hex caps above the line binding posts) and see what they look like (don't lose the parts). They will short occasionally and need to be replaced by the TELCO.

Looks like you have two lines there and its pretty messy and old. Really wish you would take my advice and have the TELCO replace those with todays version. Better protection, less problems and easier for you to connect to.

-Hal

Reno!! Get away from my asbestos-sided house!

I am not sure about everywhere but United Telephone <RIP> had a gas protector element that was a screw in replacement for the carbons on that Dmark.
They were running around SW Florida swapping them out in the 80s. In true TELCO fashion the carbons were usually left where they fell.