Here are the suffix codes for various ringer configurations of the 1543 used at that time. This list was provided by Paul Fassbender through the TCI.
A good reminder to all you new to the telephone collecting world that joining one or both of the telephone clubs is well worth the money. Much information can be gleaned, such as the information below.
TCI - www.telephonecollectors.org
ATCA - www.atcaonline.com
1543 (no suffix) = no ringer
Straight Line:
-A 5900 Ohms
-BT3 2050 Ohms
Standard Harmonic:
-E 16 2/3 Cyc.
-N 25
-F 33 1/3
-G 50
-H 66 2/3
Synchromonic
-R 16
-K 30
-L 42
-M 54
-P 66
Decimonic:
-I 20
-K 30
-Q 40
-G 50
-J 60
Note: -W suffix (before the ringer suffix) indicates a network with "fully
automatic equalization elements," so no selection, zoning or adjustment are
needed.