1955 Date for introduction of Continentals

[poplar1]

I misread your statement about the switch hook. I thought you meant that someone was having to modify the 202 switch hook in order to use it with a 685A. Still, the switch hook contacts in a 500 serve only to (1) short the receiver when hanging up and (2) disconnect both sides of the line. Shorting the receiver rather than opening it (302, 202) really doesn't make any significant difference, and it is not necessary to open both sides of the line, since a 500 can be rewired so as to connect Tip to F and repurpose those contacts for A/A1 leads on 1A2 Key. (Also, the second set of line switch contacts were eliminated on the last CS500DM sets.) So I don't see that the switch hook matters here.

While no new 202s were made after 1939, the 211/212 was certainly not manufacture discontinued before 1976. The G6 mounting (211J manual and 211L dial) contains the same switch hook contact arrangement as the 202. The extra contacts in a 212 are needed only for Tip Party ID or A-Lead Control, even when used with 685A. So the 202 and 211 contacts were not made obsolete by the design of the 425.

So in a 500, 211, 212 or 202, the switch hook doesn't change the way the transmitter and receiver are coupled with the network. And, in fact, only the 5-conductor mounting cord from the hand telephone set (202, 211, 212) allows the correct circuit, with C and RR as the input and GN, B and R the output of the network.

"For lack of a period-correct subset for an older 202-type circuit,"  as you stated: Perhaps rather than trying to make a 202 with E1 or F1 work with a 4-conductor cord and 425 network, it would be preferable just to use a 101A induction coil, as originally intended. There is certainly no shortage of 302 bases. If someone has already purchased a 685A, then perhaps one could trade it for a 302 base with one of Ray's covers. Otherwise, just a 101A induction coil and 2 MF capacitor would be sufficient for the talk circuit.

A 425B or later with 5-conductor cord may be necessary on short loops, if the 202 has an F4 handset. With an F1 or E1, however,  I would use a 634, 684 or 302 base and a 4-conductor mounting cord.

[poplar1]

The 425 network as such is not 'loaded'.  It is only so when connected as used in the 500 set, and the set therefor has additional switches.  It can be used much alike a 101A, by not employing the split configuration of the primary winding(s), which is what makes it 'loaded', in your language, in the 500 set.  Of course I would not expect a BSP to specify this, after all they hardly would have anticipated reissuing 202s when they designed the 425, and they probably knew that the re-issuance of 202s in 1955 and 56 was a short term measure to meat demand for colored telephones and use up some parts inventory until they got the color processes finished for the 500 sets. It is clear that in 1955 they did a lot of strange things to meet demand, even issuing the odd two-tone 500 sets, whether this is documented in a BSP or not.

Well, it's true that the 425 network was designed for the 500, not for 202s. However, the 685A subset, using a 425B network, was in fact created specifically for "coin collectors and hand telephone sets equipped with G-type handsets or similar handsets." This would include 202s with F4 handsets. (C31.124 Issue 1, March, 1955.)

[poplar1]

C31.124 Issue 1, March, 1955
Subscriber Sets
685, 686, and 687 Types

                1.02 These sets furnish transmission and ringing perform-
                        ance equivalent to the 500-series telephone sets and
              may be used with coin collectors and hand telephone sets
              equipped with G-type handsets or similar handsets. These sets
              should be used in transmission zone 5 to take advantage of
              improved transmission.
                     

According to Table A, in Zone 1 and 2, the "equivalent" 634CE, 634CF or 684BA should be used. "If these sets are not available from field stocks, the 685...type may be used."

[poplar1]

Interesting.  When the Continentals and Imperials came out, some had the F handset with the T1/U1 combinations that were mated with the 685A subset.  Other than the name Continental and Imperial, did they have another numerical designation other than 202 for that combination?  Does the BSP make reference to the upgrade to the 500-based technology?

Back to your original question: 202s are often coded to indicate whether they have E1 or F1 handsets: 202C-3E would be a black 202 with a dial, numbers and letters number plate, and E1. With an F1 and the same dial it would be a 202C-3F. There is a precedent for distinguishing between an F1 and an F4 however: In C32.568 Issue 1, Table A, the following 5302s are listed:

5302G-3F1, 5302G-3F4 and 5302G-G.

So it's possible that you could call a pekin red Continental a 202C-20F1 if it had an F1 handset or a 202C-20F4 if it had an F4    handset (-20=pekin red). I haven't found this documented anywhere, but it would be consistent with the 5302 coding. Still, there doesn't appear to be a different code to indicate a 5-conductor code, regardless of handset type, only the qualifier "modified." The same term "modified" is used in later BSPs  such as Section 502-302-403 Issue 1, August, 1957: Hand Telephone Sets--211J, L. With a G1A-3 handset a 211J or 211L is "as furnished," while with an F1 or F4 it is "modified."

For my own notes, I also add a sub 4, 5, or 6 after the C to indicate the dial type. (202C-3F1). (Sorry, I don't know how to type it.)
                                                                                                                               4

[unbeldi]

Bell System management probably knew that refurbishing 202s would be a short affair in 1955, and no BSPs or special part numbers were prepared for specific configurations.  Issuing 5300-series telephones was different, they knew this would be an ongoing project (10 years!), since they knew the projected lifetime of the components in the reused sets, and they designed and manufactured a new housing. And so we find BSPs for the support of that.

The F4 handset arrived about a half year into the 202 project, or a half year before it was over.

[Phonesrfun]

This has been a good discussion.

By way of connecting a "D" mount to a 685A subset, I did some work a few years ago and Bingster did some artwork to show the connections of a 202 mount to a 425 network using the standard 4-conductor cord.  This was created because some people who had spare 500 phones and no spare 302 phones wanted to be able to connect their 202 to some sort of subset.  I don't think that idea ever really caught on, but here is a link to that diagram:

http://www.classicrotaryphones.com/forum/index.php?topic=784.msg9309#msg9309

In the process of creating that diagram, I noted somewhere else that by wiring it in this manner, the network compensation circuitry of th 425 is essentially not being used, and the network is therefore being used similarly to a 101A incuction coil.  This works pretty well witht the F1/HA1 combination, because it is essentially the same as the 684A subset. 

To get the full features of the 425 network with limiting on short loops, particularly when using the T1/U1 F4 handset, the minimunm 5-wire cord needs to be used.  Even though only 50% of the 5dB gain is realized from the F style handset, 2.5 dB is still quite a gain, since every 3 dB of gain essentially doubles the volume.

I have also noticed the similarity of the 5-wire connection to that of the 233 payphone using the 685A subset.  One side of the line is switched, and the receiver is switched out on dialing and hookswitch operation rather than being shunted.

@Unbeldi, you mentioned wiring a 202 phone to a 425 network.  Hopefully the connections shown in the link I just mentioned are correct and consistent with your experience.

[unbeldi]

@Unbeldi, you mentioned wiring a 202 phone to a 425 network.  Hopefully the connections shown in the link I just mentioned are correct and consistent with your experience.

I will post my circuit diagram, that I shared elsewhere in the past, here in an appropriately entitled topic.
It surely would have been most surprising if this hadn't been discovered or rediscovered many times since 1949, and it is my suspicion that the designers of the 425 had this application well in mind during the design. Why else would they have named the terminals exactly like one would expect from the history of the prior sets: red to R, green to GN, black to B, and yellow to L2(Y).  Seemed obvious to me immediately and practice has proven it good.

[tallguy58]

For the record, I've been using a 425 network with a 202 hooked up to it for years.  Works great. No issues at all.

[poplar1]

@Unbeldi, you mentioned wiring a 202 phone to a 425 network.  Hopefully the connections shown in the link I just mentioned are correct and consistent with your experience.

I will post my circuit diagram, that I shared elsewhere in the past, here in an appropriately entitled topic.
It surely would have been most surprising if this hadn't been discovered or rediscovered many times since 1949, and it is my suspicion that the designers of the 425 had this application well in mind during the design. Why else would they have named the terminals exactly like one would expect from the history of the prior sets: red to R, green to GN, black to B, and yellow to L2(Y).  Seemed obvious to me immediately and practice has proven it good.

There could be other explanations for choosing GN, B, R and L2 besides wanting to use a 425A like a 101A. At least since 1910, green and white were used for receiver cords, and the desk stand cord green was for the receiver, yellow for transmitter, and red for common. Black was used for the second transmitter wire in the 51AL and 333B. And the terminals on a 425 are B and L2, not BK and L2Y. If indeed there was an "AT&T Standard" circuit that didn't use C on the 425 network, or otherwise permitted a 4-conductor connection between a 151AL, 202, 211 or coin collector and a 685A subset, documentation should exist somewhere. Until then, I'm not convinced.

[poplar1]

There is yet another example of using a T1 transmitter and U1 receiver with a 101A induction coil. That is, a 354 set with a G1 handset. This is electrically equivalent to using a Continental set with F4 handset and a 684BA subset.

This was done "only where station loops are too long for satisfactory transmission with the F1A hand set." However, this was considered a "temporary expedient."

C32.524 Issue 1, 1-5-52
G Type Hand Set Mountings and M Type Telephone Set Mountings with G1A Hand Set--Cording

This doesn't explain why a few years later, 5302s with G1 handsets would be installed on a permanent basis. Or why a disproportionate number of Continentals and Imperials have F4 handsets and D4U mounting cords for use with 684BA subsets.  But it does show another example of the T1/U1 + 101A Combination, in this case on loops too long for an F1 handset.

[unbeldi]

There could be other explanations for choosing GN, B, R and L2 besides wanting to use a 425A like a 101A. At least since 1910, green and white were used for receiver cords, and the desk stand cord green was for the receiver, yellow for transmitter, and red for common. Black was used for the second transmitter wire in the 51AL and 333B. And the terminals on a 425 are B and L2, not BK and L2Y. If indeed there was an "AT&T Standard" circuit that didn't use C on the 425 network, or otherwise permitted a 4-conductor connection between a 151AL, 202, 211 or coin collector and a 685A subset, documentation should exist somewhere. Until then, I'm not convinced.

Well, B already has a black wire on it in the 500, so strike that from your argument, and L2 is still L2, formerly L2Y, the connection and logic is obvious, so that doesn't count either.  The critical one is GN, departing from obviousness, that in the 500 always had a white wire, yet is named GN.

The purpose was not to construe some kind of "AT&T Standard", but to dispel this construed "requirement" of using a 5-conductor cord with a 202 and a 425 network subset which is usually offered new-comers when they want to restore an old 202 but don't have the original subset. There are indeed people advised to ditch their nice cloth cords and search for another.  It is easier to find a 684 subset than a D5 cord, and that is no doubt the preferable arrangement.

[unbeldi]

There is yet another example of using a T1 transmitter and U1 receiver with a 101A induction coil. That is, a 354 set with a G1 handset. This is electrically equivalent to using a Continental set with F4 handset and a 684BA subset.

This was done "only where station loops are too long for satisfactory transmission with the F1A hand set." However, this was considered a "temporary expedient."

C32.524 Issue 1, 1-5-52
G Type Hand Set Mountings and M Type Telephone Set Mountings with G1A Hand Set--Cording

This doesn't explain why a few years later, 5302s with G1 handsets would be installed on a permanent basis. Or why a disproportionate number of Continentals and Imperials have F4 handsets and D4U mounting cords for use with 684BA subsets.  But it does show another example of the T1/U1 + 101A Combination, in this case on loops too long for an F1 handset.

Thanks for pointing this out.  But who has actually found an M3 or M5 with a G handset? Can I have that in ivory, please? :-)

Trying to find explanations via BSPs is a nice exercise, but they weren't necessarily intended to explain anything. They were typically working documents issued based on then current circumstances and the installers didn't necessarily know the history of prior use or configuration, as old documents were yanked from distribution. Circumstances, situations, materials, supplies, economics all change, and so do the rules therefor.  One can always find a certain application, a certain loop condition, for almost any configuration of equipment, so these "contradictions" aren't really surprising, only shows that the Bell System indeed tried to reuse old equipment whenever they could get aways with it.

[poplar1]

I'm not arguing about whether or not it works fine as you have suggested. I'm just trying to find an explanation for why a good number of F4s, and not just F1s, are found on Continentals with 4-conductor cords.

I also wouldn't argue against adding a polarity guard to a 2500D before selling it to someone who would rather not try to convince Bell why polarity matters. But I would still like to understand why WE thought that a polarity guard was unnecessary.

And as far as expedience, most would prefer to use not 5, not 4, but only 2 wires. Think how many thousands of 202s and desk stands have been hot wired without that ugly, cumbersome subset. And most will say it "works" fine without a subset.

GN was probably chosen for the terminal designation because traditionally it represents the output for the receiver. They had already been using red, black and white for 3-conductor handset cords on F-type and E-type handsets. When they decided to add a fourth lead in the handset cord for G1 handsets, in order to prolong the life of the cords,  they could have made it green instead of having two white leads. But there was no need to diffentiate between the two receiver wires since the receiver is AC not DC. So they ended up with one white lead on GN and the other white lead on R. When modular handsets were introduced c. 1972, the 616W jack inside the handset and the 616D jack inside the phone originally had one white wire and one white wire with green stripes for the receiver; later this was changed to one white wire and one solid green. The green wire connects to GN and the white wire to R, although it wouldn't make any difference if they were reversed. Ironically, the line switch (switchhook)  wires that mute the receiver are red to GN and black to R.

[poplar1]

There is yet another example of using a T1 transmitter and U1 receiver with a 101A induction coil. That is, a 354 set with a G1 handset. This is electrically equivalent to using a Continental set with F4 handset and a 684BA subset.

This was done "only where station loops are too long for satisfactory transmission with the F1A hand set." However, this was considered a "temporary expedient."

C32.524 Issue 1, 1-5-52
G Type Hand Set Mountings and M Type Telephone Set Mountings with G1A Hand Set--Cording

This doesn't explain why a few years later, 5302s with G1 handsets would be installed on a permanent basis. Or why a disproportionate number of Continentals and Imperials have F4 handsets and D4U mounting cords for use with 684BA subsets.  But it does show another example of the T1/U1 + 101A Combination, in this case on loops too long for an F1 handset.

Thanks for pointing this out.  But who has actually found an M3 or M5 with a G handset? Can I have that in ivory, please? :-)

Trying to find explanations via BSPs is a nice exercise, but they weren't necessarily intended to explain anything. They were typically working documents issued based on then current circumstances and the installers didn't necessarily know the history of prior use or configuration, as old documents were yanked from distribution. Circumstances, situations, materials, supplies, economics all change, and so do the rules therefor.  One can always find a certain application, a certain loop condition, for almost any configuration of equipment, so these "contradictions" aren't really surprising, only shows that the Bell System indeed tried to reuse old equipment whenever they could get aways with it.

One of my sister's friends had a 354 (M3) with G1 handset in her basement. I have purchased two or three equipped that way. If you compare how the handset wire is dressed to the diagram in the BSP, you may be able to guess whether the handset was installed in the field or by an ebay dealer/lamp maker.

I have attempted to provide documentation of 202s, 211s, 5302G-Gs, 5302G-GF4s and 354s with T1 transmitters and U1 receivers coupled with 101A induction coils. The only BSP on Continentals that I have found is the non-technical one in the initial post. So, yes, the comparisons are inexact or out of the 1955-1956 context. Still, so far I have not found any AT&T documentation confirming your hypothesis of using 4 conductors between a 425 network and a 202, 211 or 151AL. I'm not saying it doesn't work, and it is certainly an alternative to scrapping a D4U cord. I just don't think it explains the F4/D4U combination.

[unbeldi]

Still, so far I have not found any AT&T documentation confirming your hypothesis of using 4 conductors between a 425 network and a 202, 211 or 151AL. I'm not saying it doesn't work, and it is certainly an alternative to scrapping a D4U cord. I just don't think it explains the F4/D4U combination.

I never had any such intention, and I think I made that clear from the beginning. The 425A network is not a revolutionary new telephone circuit, despite its rather new looks, but an evolutionary result, and the designers were very clearly aware of its history and compatibility with previous designs. But the combination is clearly not desirable, perhaps these were created by the operating companies without WeCo or Bell Labs involvement, as those would be the ones writing BSPs (for the most part). Perhaps these are only documented in the so far elusive repair center practices. Similar with the T1/U1/101A combo. Only here they created a new product (5300/5400 housings) in the factory, and thus WeCo and Bell Labs were involved, and promptly we have a BSP.  I don't know where F4s were made, but from their construction, it seems an easy job for the refurbishing centers and from samples it appears that handsets used were not always defect free, i.e. factory fresh. But in any case, the concept of F4s appears to be originating at the Bell Labs level, as the AT&T history volumes have entries for that accomplishment, IIRC.