In cities, if you had a party line (2 or 4 party) you had a listed
> number the same as anyone else. If someone called you, they dialed
> the listed number normally and only your phone rang. The Bell System
> used a special wiring technique to isolated the ringers of up to four
> separate parties so only the desired party would ring. (I believe it
> was a combination of bias and grounding). The independent companies
> used different ringer frequencies to isolate ringers.
> However, in many places, party lines had a letter suffix (J, R?). In
> the literature, the panel readout boards had that letter suffix. Some
> old telephone books show that letter listed after to the number.
> I presume in some manual systems one gave the letter to the
> operator.
I lived in several manual exchanges and one did give the letter to the operator. This told her which ringing key to use.
I also lived in a dial exchange that had terminal-per-line step equipment. This meant there was one terminal for each line -- a party line had an additional digit. The number for my busines was 234. Individual (one-party) lines had three-digit numbers. Party lines had four digit numbers, such as 4551. The last digit (usually a 1 or a 2) told the connector which ringing current to apply.
This was long before DDD or the national numbering plan. Terminal-per- line had a number of drawbacks, such as the fact that if intercept service needed to be provided, both parties' numbers had to be intercepted and the caller asked which number they were called ... also regrouping party lines required changing one or both customers numbers.
Larger places, and eventually all places, went to terminal-per-station, which meant the number of a party line was a normal number and the connector was wired for which type of ringing current to apply.
Eight-digit numbers would certainly be possible before the days of uniform numbering, although I never encountered any. Tulsa had a combination of four-, five- and six-digit numbers. Oklahoma City, originally set up for dial service with all five-digit numbers, later had some six-digit numbers.
But in dial systems, did one dial the suffix letter to reach party > lines so equipped?
> Note -- the above is for party lines of up to 4 customers. I believe
> anything beyond 4 had to be on a manual system and had to use special
> short-long ringing codes. Everybody heard the other phones ringing
> and had to listen if it was their code. (Or they always answered to
> listen in on other people's conversations.)
Not all places had provision for more than two types of ringing. Others had four, as you suggest. Many non-Bell companies used harmonic ringing which, at least in theory, could provide for eight or
10 distinct parties with single ringing. Some were more reliable than others.
Wes Leatherock snipped-for-privacy@aol.com snipped-for-privacy@yahoo.com
[TELECOM Digest Editor's Note: Am I correct in thinking that all party-line subscribers were geographically close to each other (such as a few doors away, or across the alley?) Were they nearly or always on the same cable out of the central office? Or were there party line subscribers across town from each other? PAT]