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- Date: 14 May 85 16:04:49 EDT
- From: *Hobbit* <AWalker@RUTGERS.ARPA>
- Subject: Wiring
- To: Telecom@RUTGERS.ARPA
-
- It's rather difficult to send out schematic diagrams to a network of
- people using regular old ascii terminals, but since wiring inside most
- fones is pretty standard, a description should do the trick. This
- applies to *all* WE phones and ITT phones that use the standard
- dial/ringer/network block/ handset configuration. I've rebuilt lots
- of these suckers, and can confidently say that they're all the same.
-
- Everything basically talks to the network block. The network block
- contains the ringer capacitor, the induction coil that handles the
- handset, and very little else save some spare screw terminals. Left
- to itself, the network block can function as a standard line load [it
- looks electrically like a phone] when a line is connected across RR
- and C. These are the inputs to the coil. The ringing capacitor is
- indeed across A and K as someone mentioned. In addition, older blocks
- have a smaller capacitor across F and RR, to decrease sparking across
- rotary dial contacts.
-
- Handset:
- Green and White: Earpiece leads. These connect to net R and GN respectively.
- Black and Red: Mike leads. Connect to net B and R respectively.
-
- Ringer [two-winding]:
- Black and Red: To line. Connect to L1 and L2 [or whever your line comes in].
- Grey and Grey/red [these may vary; they are the ''other two'' wires, anyway]:
- Connect to net A and K. The circuit thus formed runs from one side
- of the line to one ringer winding, thru the A-K cap, thru the other
- ringer winding, to the other side of the line. This configuration
- has infinite DC resistance, but picks up the AC ring voltage.
- Ringer [one-winding, rare]: Connect the single winding [two wired] in
- series with the A-K capacitor somehow, and this whole thing across
- the line as above.
-
- Rotary dial:
- Blue and Green: Interruptor. Connect to net F and RR.
- White [2]: Earpiece suppress. Connect to net B and GN if desired.
-
- Touch-tone dial:
- Green: + Line in. Connect to net F.
- Black: + Line out. Connect to net RR.
- Org/Blk: - Line in. Connect to net C.
- Red/Grn: output common. Connect to net R.
- Blue: output. Connect to net B.
- *Note: the above 5 connections will give you a ''bare-bones'' dial
- configuration without features. Features are mike disconnect, earpiece
- suppress, etc which are done simply by routing leads to these through the
- extra contacts on the dial instead of directly. If you want the features,
- modify the wiring as follows. If your network block doesn't have the S and
- T terminals, you have an old one designed for rotary dials, and you'll have to
- do kludges.
- Earpiece mute:
- Move Handset lead at White to net S. Also connect Dial White-Blue to net S.
- Connect Dial White to net GN. This routes the earpiece through
- the dial switching mechanism which resistifies the circuit on button press.
- Mike disable:
- Move Handset Red to T. Also connect Dial Red to T. This completely disables
- the mike on button press. Make sure Dial Red-Green is connected to R if you
- do this mod!
-
- Hookswitch:
- You'll find many variants of this in different units; some configurations
- switch both sides of the line, some only one, some switch out the ringer
- when off-hook [which isn't necessary, really]. The following should work:
- Yellow: Connect to net L2. This is where the line enters.
- Brown: Connect to net C.
- Green: Connect to net L1. This is the other side of the line.
- White: Connect to F. This is switched line power to the dial and the rest.
- Red: Connect to R. This, with Black, is shorting earpiece mute.
- Black: Connect to GN.
-
- Line in:
- Green and Red connect to L1 and L2. Try one polarity; if the touchtone dial
- doesn't work, then flip them. Rotary dials, of course, don't matter.
-