**Low Impedance and High Impedance Ringers and 40xx/50xx Versus 41xx/51xx Base Codes**

Here are a few examples of typical Base Codes on AE40, 47 & 50 telephones:

(AE40) N4025 A5 TB1

(AE40) L4044 D50D EH7

(AE40) L4123 ESLT P6

(AE47) L4111 ASL RU6

(AE50) PL 5001 K0 ??

(AE50) SZL5002 A0 GB9

(AE50) L5100 ESL HU4

The first part of the AE 40/50 Base Codes that we feel has been deciphered is the relation between the two common ringer styles used in these phones and the change from the 40xx and 50xx Base Codes to the 41xx and 51xx Base Codes. Jack Ryan pointed this out awhile ago saying that he felt that the introduction of newer "Type 45" (smaller) High Impedance Ringers also related to the change in codes from 40xx to 41xx and 50xx to 51xx numbers in the first Section of the Base Code.

I have 39 phones in my Base Code records that have enough information to properly check this out. Here is the results of the survey:

40xx sets had 14 Low Impedance Ringers and 0 High Impedance Ringers installed.

41xx sets had 0 Low Impedance Ringers and 5 High Impedance ringers installed.

4111 (47) sets had 0 Low Impedance ringers and 2 High Impedance Ringers installed.

50xx sets had 10 Low Impedance Ringers and 0 High Impedance Ringers installed.

51xx sets had 2 Low Impedance Ringers and 6 High Impedance ringers installed.

Notes:

-Most of my records of AE 47 (4111) sets had Z rather than L or N coding and the other numbers don't directly identify them as 40xx versus 41xx sets so only the L/N coded sets were included here.

-Two 51xx AE50 sets DO HAVE low impedance ringers in them but they are both SL ringers in sets coded as originally having frequency ringers so these ringers have been swapped out later and the low impedance ringers must have been all that was on hand.

http://www.classicrotaryphones.com/forum/index.php?topic=17379.msg180407#msg180407So the end result is that we feel we have enough information to declare Jack Ryan Correct"!

Terry

1st Picture - Older Larger Low Impedance AE Ringer

2nd Picture - Newer Small High Impedance AE Ringer