W.E. 102, 202 and subset easy wiring diagrams

[markosjal]

What is an answer-only telephone ?  No transmitter ?   A manual, no-dial phone is good for answering and originating.

Like a Butt set without monitor mode and no dial . It was encased in an AE handset. Simple switch near cord  for on / off.

I later replicated it in a WE handset with a buscom soft touch (microphone replacement with touch tone keypad) to make it into a full phone. Yes it was a Frankenstein however a good frankenstien. I always wanted a simple mount on wall hookswitch for it and never found one.

[markosjal]

...Circuit for the RC 'network':
http://www.classicrotaryphones.com/forum/index.php?topic=10617.msg112976#msg112976



The term 'mini-network' is generally accepted for the small PCB-based transmission units by ITT and AE, which are perfectly well-performing AST hybrids.

The problem with this diagram specifically on say the 202 is that it would require a four conductor handset cord.

I just crammed the R/C "Micro network" into a 202 with F1 handset and made some refinements to accommodate the 3 conductor handset cord. I will try to document it and diagram it. I also did it without adding any more terminal strips in the phone (at one point I thought that was impossible). I hot glued the Capacitor to the middle of the base and came up with a "quick connect" method for it so the base with capacitor can be completely removed and reinstalled more easily. The resistor connects at one end to an existing terminal and the other end has another "quick connect" . This quick connect on the resistor was simply a way to avoid adding another terminal. 

After having made 2 calls now am quite impressed as the sidetone is not that bad. It would be nice if there was a little less. But it is perfectly usable at least on my UTStarcom IAN-02EX VOIP ATA.  Also interesting is using the "Makes last" contacts, i get no loud popping. I suspected I would still need a varistor, diac or dual diodes across the receiver but see no need. 

I will also be posting what I remember of a "better micro network" as I do remember the component layout (all four of them) to which the handset , and hookswitch connected. Maybe some genius here can figure out where what all connected and component values. I must have built it 100 times as a kid for lack of real phone networks. Oh yea that was before Internet and I was the "weird kid" collecting old phones.


Mark

[poplar1]

The problem with this diagram specifically on say the 202 is that it would require a four conductor handset cord.

If the hookswitch had only 3 make contacts, then a 4-conductor handset cord would be needed. With 2 sets of 2 contacts, as in a B1 or D1 mounting, then only a 3-conductor handset cord is needed.

In both a 20-AL and a 102, when off-hook green goes to the receiver, yellow to the transmitter, and red to the common trans./rec. In both, one side of the transmitter and one side of the receiver are opened when hanging up. In both, the receiver opens first to prevent acoustic shock (pops in the receiver).

[markosjal]

If the hookswitch had only 3 make contacts, then a 4-conductor handset cord would be needed. With 2 sets of 2 contacts, as in a B1 or D1 mounting, then only a 3-conductor handset cord is needed.

In both a 20-AL and a 102, when off-hook green goes to the receiver, yellow to the transmitter, and red to the common trans./rec. In both, one side of the transmitter and one side of the receiver are opened when hanging up. In both, the receiver opens first to prevent acoustic shock (pops in the receiver).

As I said "In this diagram...." please see attached . There you will see the handset circled and there MUST me 4 wires to said handset according to THIS diagram

Mark

[poplar1]

Both this diagram, and the one that I was replying about, are of a desk stand, not a 202. Despite the fact that the hookswitches in both diagrams are drawn as if they have 2 pairs of contacts -- as the Y/BK and the GN/W in a 202, if you look closer you will see that the contacts are labeled R/W and R/YY. In fact, both Rs are the same contact spring, and the 3 springs make to complete the path from the R terminal to both the transmitter (YY) and the receiver (W)....The first diagram also has "desk stand" designated in blue.
So the transmitter and receiver are separate units, not a handset.

With 3 contact hookswitch, 4 conductor handset cord would be required. But a 202 has a 4-contact hookswitch.

Hopefully, unbeldi can better clear up the ambiguity of the two R contacts in each drawing.

[unbeldi]

Hopefully, unbeldi can better clear up the ambiguity of the two R contacts in each drawing.

The diagram is a circuit diagram, not a wiring diagram.   Having two Rs only means that it is the same terminal, as is the case of the well-known configuration of a three-leaf hookswitch of a simple candlestick.  A circuit diagram shows the logic of a circuit, not necessarily the actual connection points.  One can design the logic of the two switches in many different physical expressions.

The diagram expresses a general method.  It should not matter whether the attached desk set is a 102 or a 202, with the reservation of not connecting the black wire in case of AST sets.  It is only important to adhere to the standard color coding of the conductors in the WECo mounting cord, which produced the receiver signal across green and red, and carries the transmitter signal between red and yellow.  The same applies to the simple RC adapter.

The simple RC 'network'  functions by using the resistor as the audio source for the receiver.  The voltage drop caused by the received audio signal across this resistor provides the audio power for the receiver.  The resistor should be adjusted for optimal listening experience, enough loudness and minimal signal reflection (echo) and will probably end up falling into the 200 to 600 Ω range.  The standard terminating impedance for telephone sets is 600 Ω.  So the resistor value depends on the impedance of the receiver used, and the length/line impedance of the local loop.   The capacitor only serves to block direct current flowing through the receiver, and should therefore be dimensioned large enough to not attenuate the signal unduly.  2 µF might be adequate, but larger is just fine.

[unbeldi]

As I said "In this diagram...." please see attached . There you will see the handset circled and there MUST me 4 wires to said handset according to THIS diagram

Mark

Again this diagram is schematic only.   In a telephone with a hand-held receiver and fixed transmitter, there are four wires, but when a combined handset  is used, it was customary to use a common return conductor for both transducers.   In that case the center two conductors are a single one and only a single two-point switch would be needed, if you can bear the popping noise. But since that was an unacceptable performance issue the designers added additional switches to make sure the receiver is the last element connected after establishing the direct current circuits of the telephone.  The precise way this was accomplished in each telephone type is almost always the only difference between the circuits of the model lines.  The principle of circuits was essentially the same.  Once you understand the principles, you can wire any telephone in a correct manner with whatever switches you have available, if at least sufficient.

PS: a possible layout when using a handset telephone, with two separate switches as found in the B1 or D1.  In practice, the  WECo circuit for the D1 handset mounting in the 202 telephone also moved the second switch in the red common handset conductor to the yellow wire, as shown in the last schematic.

[markosjal]

Is there a collection of these diagrams posted here somewhere? for instance 202 with dial?. I posted a thread about my 202 wiring with mini R/C network can do a diagram.

[dsk]

Is there a collection of these diagrams posted here somewhere? for instance 202 with dial?. I posted a thread about my 202 wiring with mini R/C network can do a diagram.

My 202 with a dial: http://www.classicrotaryphones.com/forum/index.php?topic=16538.msg171093#msg171093
I hope this may help.

dsk