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.
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 ?
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.
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.
Here are some photos.
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.
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.
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.
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.
Here are pics of the handset receiver element. The transmitter is a standard F1.
It is smaller and has a spacer, which can be seen in the photo. It sure does sound good. The handset is marked F1.
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.
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...
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.
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.
With a 6U dial, the set has to be wired differently than what I showed in my first diagram, because these Design Line dials have contacts to shorted the receiver, rather than open the receiver circuit.
I reworked the diagram for that dial, added all switch terminal designations, also using the colors of the D6AA mounting cord that is used in this set.
This is how I would wire the set with the given components.
I would use the spare R terminal in the D1 to connect the black wires from the handset and from the subset, not tie up the hook switch contact Y, which makes the Y-BK switch unusable. So your craftsman had to use the GN-W hook switch to cut off the line, instead of disconnecting the receiver before the line breaks. This should cause clicks in the receiver when operating the hook switch, for example to get new dial tone after a call, rather than hanging up the handset physically. But since he did leave a varistor across the LB1 terminals, the clicks might be minimal.
I selected the blue and white wires of the D6AA cord the way I think they are used in your set, though I have not traced the wires in your pictures precisely. There is something different going on with the yellow wire. Has he placed the dial pulse switch (DP) before the hook switch ? I think this would be a mistake, because in that case the spark quenching RC filter between F and RR in the 425B network cannot function. The dial pulse contacts BL-G must be across F and RR. No, it seems he used the yellow wire instead of green in my case, going directly to DS2 to short the receiver. I definitely prefer green going to GN terminals.
The BK-R switch on the dial remains unused, as is the case on your set, because using it would require two more wires in the mounting cord, to shorten C and RR terminals on the network during dialing. This would be a good choice actually, because it eliminates the entire desk set, including the primary windings of the induction coil during dialing, as is the practice in the old 302 telephones.
I truly appreciate all the input and extensive information. I figured I had something outside the norm when I first opened it. It will take me awhile to process all of this because I am not nearly as educated in electrical engineering as you folks. I have apparently joined the right group to feed my telephone collecting bug. I look forward to much more of this.
Quote from: Butch Harlow on August 11, 2017, 06:00:14 PM
I truly appreciate all the input and extensive information. I figured I had something outside the norm when I first opened it. It will take me awhile to process all of this because I am not nearly as educated in electrical engineering as you folks. I have apparently joined the right group to feed my telephone collecting bug. I look forward to much more of this.
You have. Happy to help. I'm sure the others are too. That's what CRPF is for.
Being somewhat eBay lucky, I came across another Imperial that has all the proper parts I need to restore the one I have to original. Luckily it is just dinged up enough for me to not really care about mining it for parts. It has a 6D dial, proper cloth jacketed 3 conductor curly handset and cloth jacketed 4 conductor straight line cord that appear original. The handset has a big chip in it and was also repainted to an incorrect light almond color, so was the hookswitch plunger. The transmitter element is a T1 with two odd spacers, which I have never seen before, but is dated 1-55 like the rest of the phone's elements. The receiver is a U1 dated 1-10-55. So, I think I got all the correct parts to return my imperial to original, factory spec.
My questions pertain to the wiring, and if what is currently wired would be correct.
The subset cord is wired as follows:
Green to GN on hookswitch
Yellow to Y on hookswitch
Red to R on dial
Black to BK on dial
(which seems kinda obvious to me, haha!)
Handset cord:
Red to R on dial
black to BK on dial
White to W on dial
(also, kinda obvious)
two Jumpers, one appears new:
W on hookswitch to BB on dial
BK on hookswitch to Y on dial
also, the handset cord restraint is stamped H3P and under that II 55, the subset cord restraint is stamped 55 and has a string to tie it down in addition to the hook restraint.
Quote from: Butch Harlow on December 20, 2017, 07:37:36 PM
My questions pertain to the wiring, and if what is currently wired would be correct.
The subset cord is wired as follows:
Green to GN on hookswitch
Yellow to Y on hookswitch
Red to R on dial
Black to BK on dial
(which seems kinda obvious to me, haha!)
Handset cord:
Red to R on dial
black to BK on dial
White to W on dial
(also, kinda obvious)
two Jumpers, one appears new:
W on hookswitch to BB on dial
BK on hookswitch to Y on dial
also, the handset cord restraint is stamped H3P and under that II 55, the subset cord restraint is stamped 55 and has a string to tie it down in addition to the hook restraint.
That is the correct wiring, using the D4U mounting cord connected to a 684 or 634 subset.