Wiring an AE 1A to a WE 685a subset with 425E module

[spadetip]

I am a new member and this is my first post. I have an AE 1A with 4 leaf hook switch, no induction coil and a 4 cond. cord [red, grn, yel, wh] to the subset. The set is in great condition, but the wiring has been messed with a lot. I have corrected the set wiring to the original, per a circuit diagram I found on TCI, "H-17824 to work with Type 21 subset". However, I don't have a Type 21, I have a 685a with a 425e module. I was able to locate a 425e connection drawing from this site [685-525.png] and a 685/425e schematic from TCI. Using these 3 drawings, I have been able to get everything working using the connection information below. Set rings, answers and dials out. Tx and rx levels are good and the receiver is shunted when dialling. The only issue is the sidetone- it's better than other combinations of wiring on the 425 I have tried, but still is too loud. As indicated below, I am using a 4 con. cord, but I have a second cord should a fifth connection to the subset be required. My current connections do not use terminals GN or F on the 425e. My questions are:

1. Do I need a 5 conductor cord? 2.  If 4 conductors are adequate, are my current connections correct, if so, can I expect any sidetone improvements?  3. What about the unused connections GN and F on the 425e?

Here are my current connections- I have used the 685 term strip for the line and ringer connections, which I have omitted as the ringer works fine.

4 cond . cord, grn, red, yel, wh

Tel. terminals:
grn  #4 of set to L2 of 685 term strip
red  #3 of set to C of 425e [also a strap to from C to #2 of term strip- no other connections here].
yel  #2 of set to B of 425e
wh  #1 of set to R of 425e

Term strip- 685:

Strap L1 to RR of 425e
Strap L1 to G to enable ringer
Strap #2 to C of 425e
Outside line connects to L1 and L2 of term strip

Ringer leads connected per 685a subset schematic, including use of capacitor between connections A and K of 425e.

So that's about it. I realize this is a long post, but I thought it best to get all the relevant information on one message. Any and all suggestions or corrections would be greatly appreciated.
Thanks
spadetip     
 

[poplar1]

Using a 425 network and a 5-conductor cord will also require rewiring the phone. Unlike the original wiring for the phone, the line switch and the dial (2 wires) are isolated completely from the handset (3 wires). You might want to look at the diagram for a WE 211 found in BSP 502-302-403 in the TCI library.

http://www.telephonecollectors.info/index.php/document-repository/doc_details/2761-502-302-403-i1-211j-l-telephone-sets-tl

[poplar1]

The 685A subset should work as intended if you use a 5-conductor cord.

Input of network: RR and C

Output of network:
Receiver to GN
Transmitter to B
Common transmitter/rec to R

The line connects to L1 and L2 of terminal strip. (OK)
There is a blue strap from L1 to RR. (OK)
There is a brown strap from 2 to C. (OK)

Connect one pair of hookswitch leaves (or hookswitch and dial pulsing contacts in series for a dial phone) to L2 and 2 on the subset terminal strip.

Thus, when the phone is off-hook and the dial is at rest, there is continuity from L2 through the hookswitch and dial to 2 to C. And a permanent connection from L1 to RR.

You can also short the receiver out while dialing by connecting the other dial contacts in parallel with the receiver.

[spadetip]

Thanks for this information. I'll be able to work on the wiring changes this week and send another reply with my results. 

[spadetip]

Using the wiring changes provided by poplar1 and the addition of the fifth cond. in the subset cord solved the high level of sidetone issue. The set is functioning perfectly, including rewiring of the dial shunt contacts to the receiver.

Many thanks, poplar1