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Western Electric Imperial D1/685A wiring

Started by Butch Harlow, August 10, 2017, 08:52:28 PM

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Butch Harlow

I was hoping someone could direct me to wiring diagrams for an Imperial phone. The mounting cord has 6 wires (red, black, yellow, green, light blue, and white. It is mounted to it's original 685a subset. Thanks in advance.
Butch Harlow

unbeldi

#1
Quote from: Butch Harlow on August 10, 2017, 08:52:28 PM
I was hoping someone could direct me to wiring diagrams for an Imperial phone. The mounting cord has 6 wires (red, black, yellow, green, light blue, and white. It is mounted to it's original 685a subset. Thanks in advance.

Really?  Six wires?  That's a first, I think.  I am wondering what kind of cord this is. Can you show a picture?

The original cord on the Imperials typically was a four conductor ivory D4U-4.  I also believe that Imperials most likely always were installed with a 684A or BA subset, although the 685A did came out in the Spring of 1955, the same years as the Imperials.

But a six-conductor cord can indeed be used between the D1 and a 685A subset.  With it, all technical improvements of the 425B network in that subset are accessible.  Actually, a 5-conductor cord is quite sufficient.

The arguments for using four-, five-, or six-conductor mounting cords are somewhat long winded, and have been presented on the forum before, IIRC.
How skilled are you in wiring D1 handset mountings and reading diagrams ?

Butch Harlow

It's definitely a first for me to find six wires. I will post pictures shortly. I did figure out that it was wired properly, but not to ring. I managed to get it to ring by moving the black ringer wire to L1. I can read wiring diagrams quite well, I have rewired a few in my short time in the hobby. Stay tuned for photos. 
Butch Harlow

Alex G. Bell

Quote from: unbeldi on August 10, 2017, 09:03:50 PM
Really?  Six wires?  That's a first, I think.  I am wondering what kind of cord this is. Can you show a picture?

The original cord on the Imperials typically was a four conductor ivory D4U-4.  I also believe that Imperials most likely always were installed with a 684A or BA subset, although the 685A did came out in the Spring of 1955, the same years as the Imperials.
Some years ago a friend here picked up an Imperial which was connected to an apparently WECo shop-painted 685A-50? -4? (ivory) subset by a 5-conductor ivory textile jacketed rubber insulated mounting cord.  Apparently it was done.  Perhaps they did this when necessary for transmission zoning reasons.

Of course we know 6-conductor mounting cords existed for other reasons.  Perhaps it was swapped in for repair or some other reason, such as length.  Let's see what it is and what color it is.

Butch Harlow

Here are some photos.
Butch Harlow

Butch Harlow

The mounting cord is a vinyl coated 6 conductor. I hope the photos are clear enough to make out. The ringer black wire had been wired to "G". Moving it to L1 enabled the ringer. The phone works perfectly and has a very nice audio quality. It dials and receives. I am going to assume it's wired correctly at this point.
Butch Harlow

unbeldi

Thanks for the pics.

The wiring job on this phone is not original. It was done by a knowledgeable after-market person, perhaps a collector. Cable ties are never original, but the work was done neatly. The handset cord is also a newer vinyl type.

The dial is also not original. It is a 6U dial from the 1970s.  This type of dial was used for Design Line telephones which adhered to the wiring principles of the 425B network and U1 and T1 elements in the handset.
What kind of elements does your F handset have ?   It may be an F4 if it has those newer elements from the 500 set.

unbeldi

#7
Here is a circuit schematic for a 6-conductor setup with a 5J or 6D dial. I don't have an exact wiring diagram that shows the precise connections.
This is to show the circuit principle to show what needs to be accomplished.  As a result the six mounting cord wires are not neatly bundled as a cord, but are shown schematically by the coloring of lines and elliptical lines.

Perhaps you can trace it to see whether it fits your set. It won't.

Alex G. Bell

Quote from: Butch Harlow on August 10, 2017, 10:07:50 PM
The mounting cord is a vinyl coated 6 conductor. I hope the photos are clear enough to make out. The ringer black wire had been wired to "G". Moving it to L1 enabled the ringer. The phone works perfectly and has a very nice audio quality. It dials and receives. I am going to assume it's wired correctly at this point.
I don't see a full view of the handset but it looks like perhaps it has a 4-cond. handset cord with a bushing for a G-type handset. 

What elements are in the handset?  An F1 transmitter and HA1 receiver (standard for an F1 handset) or a T1 transmitter and U1 or HC5 receiver (used in an F4 handset to make it equivalent to a 500 set when connected to a 685A subset)?  Is the handset marked F1 or F4? 

If it's an F4 equipped with T1 and U1/HC5 that would explain why it sounds so good to you.

Normally the ringer circuit connects to the YL lead via G, with its other end connected to RD or GN, so that by putting the YL lead on the opposite line terminal at the wall, (GN or RD) the ringer is bridged without opening the subset, or the set can be connected for party line service, again sometimes without opening it.

Butch Harlow

Here are pics of the handset receiver element. The transmitter is a standard F1.
Butch Harlow

Butch Harlow

It is smaller and has a spacer, which can be seen in the photo. It sure does sound good. The handset is marked F1.
Butch Harlow

poplar1

The 6th wire (white) connects to F on the network so that the dial filter is used, as in a 500.

Seems odd that they used the Y hookswitch terminal only to connect the two black wires, and therefore only 1/2 of the hookswitch. So the receiver isn't opened by the hookswitch.
"C'est pas une restauration, c'est une rénovation."--François Martin.

Alex G. Bell

Quote from: Butch Harlow on August 10, 2017, 10:22:56 PM
Here are pics of the handset receiver element. The transmitter is a standard F1.
That's an LB1 receiver first used in Trimline handsets.  I don't know of a spacer ring intended for that but when the HC5 was used I think it required a ring so perhaps the same ring fits both.  Interesting...

Alex G. Bell

Quote from: Butch Harlow on August 10, 2017, 10:24:32 PM
It is smaller and has a spacer, which can be seen in the photo. It sure does sound good. The handset is marked F1.
I take it that the reference to "smaller" and" spacer" is in reference to the size of the LB1 receiver unit.

As unbeldi noticed (I never enlarged the photos so I missed some details), the cable ties are a sure sign of the set having been worked on by non-telco party, though apparently a knowledgeable one.  The LB1 receiver is more sensitive than the original HA1 so the 685A subset would be the best choice to prevent excessive sidetone.


Alex G. Bell

Quote from: poplar1 on August 10, 2017, 10:26:14 PM
The 6th wire (white) connects to F on the network so that the dial filter is used, as in a 500.

Seems odd that they used the Y hookswitch terminal only to connect the two black wires, and therefore only 1/2 of the hookswitch. So the receiver isn't opened by the hookswitch.
Good observation.  In that case the line is being switched by the GN & WH contact set, so even if they had used both the contact sequence would be wrong and there would be a click, hence no perceived benefit from using both.

To make it right the receiver circuit should be using the GN & WH and the line should be switched by the YL & BK.

Aside from clicking, it may be possible to eavesdrop (weakly hear speech on the line when the cradle bar is depressed) unless the receiver is switched properly by the GN & WH contact set.