My Bits O' Phone 5302

[ntophones]

About those handsets--did they make the different models (F1, F2, etc.) at the same time, or did the F1 come first and then the others were like software upgrades? And, did they all use the F1 body, but different wiring configurations?
That is so interesting. I never knew all that before.

[Phonesrfun]

My assumption is that the F1 and the F2 handsets were made concurrently.  I say this because the earlier E style handset came in an E1 and an E2.  The E1 was the standard handset, and the E2 was wired for four conductors, I.E. for switchboard use.  It is interesting that when the 500  phone came around they equipped all G handsets with four conductors instead of three.

In the three conductor handset cord, the receiver and transmitter share a common lead.  In the four conductor hanset cord, there are a pair of wires for each of the transmitter and receiver. 

On the 500 model phones, one of the transmitter leads and one of the receiver leads are still connected to the same common terminal "R" inside the phone, which appears to do the same thing as having three wires in the cord instead of four.  There is, however, a reason for this.  Does anyone care to explain that?

Was it:

A.  To use up more wire in the manufacturing process
B.  To make all handsets the same and eliminate the switchboard version
C.  So cords would be fatter with one more conductor
D.  For current isolation in the receiver circuit for click reduction

[McHeath]

I read a long transcript of a press conference Bell Labs had in 1949 to introduce the new 500 model.  They talked about the move from 3 to 4 wires in the handset cord, as well as the specifics of the new cord.  It was, paradoxically, a cost cutting measure in the end.  They claimed that with four wires the cord would give better length of service and thus require fewer replacements. 

The new cord was neoprene rubber, and was given a grommet at the handset end to make it more durable as well.  The cord cost more than the cloth cords of before, with it's grommet, neoprene case, and 4 wires, but they figured that overall they would save money as it was made better and would last longer.

I thought that was pretty amusing in an ironic sort of way, a company spending more money to make a more durable product to save money overall.  Not exactly the way the world works now.

[Greg G.]

But that was "back in the day" when the phone belonged to THEM, and THEY had to fix it at THEIR expense, so it actually made sense.  As collectors, aren't we glad they went with durability?

[HobieSport]

Yep.

[Phonesrfun]

By the way, the correct answer to the question raised a couple of postings ago is D.  I won't go into the technicalities here because they are pretty subtle at best.  If anyone wants a technical discussion of this  refer to Ralph Meyer's book Old-Time Telephones!, pages 166 and 167.

By the way, the 5302 is performing perfectly.  I like to kind of rotate the use of my phones around.

[McHeath]

Here's the link to the transcript of the press conference introducing the model 500.

http://www.telephonecollectors.org/DocumentLibrary/WesternElectric/500-Set-Design-1949.pdf

The information in question, moving from 3 cords in the handset cord to 4, is on page 8, they discuss the move to a jacketed cord and grommet on page 7.

[Phonesrfun]

Heath:

That is interesting, and I hadn't seen it before.  I saved it though.

Interesting that there are two seemingly different accounts on why the fourth conductor, although the one you presented also talks about lowering the resistance.  So, I guess I have to concede that maintenance was a design criteria too.

One thing that came out of that article is the improved efficiency of the T1 transmitter and the U1 receiver over the older F1 and HA1 counterparts.  I can attest to that, because my Imperial with a modified F1 handset has a T1 and U1 receiver/transmitter combo. Since the Imperial is using a subset that is not an equalized subset, but rather a 684A which uses the 101A induction coil similar to a 302, there is more sidetone in the Imperial than a standard 302 or a 500.

Oh well, I am getting kind of out there on this discussion. Probably time to put a cork in it, since I am no engineer and I am likely to get myself in trouble.

[Dennis Markham]

Bill, in reading this post tonight it caused me to think a little bit (just a little bit) about a 5302 that I have.  I acquired a white 5302 a while back.  

Seen here:

http://www.classicrotaryphones.com/forum/index.php?topic=1155.msg14605#msg14605

The hard plastic housing and handset, including elements are from 1960.  It's been sitting here in my office for a while and I decided to plug it in and use it.  I noticed while talking on it that there is more side-tone than a 500 set or what a 302 would have.  Since many 5302's have the F1 handset and 3 conductor handset cord it is wired like a 302.  The cords on this were obviously made for the model 500 as is evidenced by the strain relief (dated 60).  So the 4 conductor handset cord may be wired improperly.  Would you concur that the connections of the handset should be as follows?:

Red Wire/White wire to "R" on the 101A Induction Coil.
Black Wire to BK on the Dial (#6 Dial)
Second White wire to "W" on the dial.

When I first used it the hollow sound, which I think is side-tone was very evident.  I thought the "cotton acoustical barrier", aka cotton ball was missing.  It is not.  The handset is a G3 with T1 and U1 element dated from 1960.

[Phonesrfun]

Dennis:

I believe the higher level of sidetone is exactly what I am experiencing with my Imperial.  The T1 and U1's are definitely more efficient, and were designed more to be used with the equalized 425 network, although it was not uncommon for them to use the later handsets on the 5302.  I believe they made a GF handset just for the 5302 which was a G handset which used the older elements, simply because on shorter loops the increased efficiency could be objectionable.

I believe the later elements were, in fact used because there is a wiring diagram somewhere that I have seen that prescribes how to wire the second white wire to the red wire on the R terminal on the 101A induction coil, just as yours is wired.  So, your wiring is correct.

Your white 5302 is stunning, by the way.

[Dennis Markham]

Thanks Bill for the compliment on the phone.  It has some issues, but I'm glad to have it.  I never really took the time to look "under the hood" until tonight.  It's very dirty inside and it is now on my list of things to do.  This handset is the standard G3.  I don't know the history of the phone but since the housing date matches the handset and element dates I would assume this was a phone company issued phone.  The side tone is not objectionable but evident.  Thanks for your view on my question.

[AET]

I had no clue they made 5302's in colors besides black. I learned something today!

[McHeath]

It's interesting digging about trying to figure out why they put 4 wires in that handset cord back in 49'.  I like this kind of historical detective work, and it helps that the Internet makes these source materials available so easily instead of spending hours in a musty archive paging through yellowed pages.  Undoubtably there may be more than one reason that they went from 3 wires to 4, the transcript clearly lists two reasons, maintenance and resistance, and perhaps there were more. 

If you have the time the transcript is fascinating reading, it's like a window into the designers of the WE 500s minds.  They don't miss much in the discussion, even the type of plastics are discussed, as well as future colors.  Even some of the geo-political realities of the era are discussed, it's a long read but worth the time. 

[Greg G.]

I looked through that pdf for something about production dates.  PDF page 19, (document page 109) has this:

Question:  When is production scheduled to begin?

Mr. Tuffnell:  The matter of production is a bit complicated because of the impending move of the station plant to Indianapolis.

So, if this conference was already half way into 1949, and they were going to move a plant, could it be that production didn't start until 1950, meaning there were no 49ers?

On a side note, that conference had a lot of really, really, dry tech stuff, glad I wasn't there.

[McHeath]

I would interpret the start of production the same as you.  Probably any 1949 model 500s out there are preproduction test units seeded in the various trials that have survived somehow. 

Yeah it would have been a pretty long and technical press conference eh?  It's also interesting to compare this conference with modern ones where we introduce new products today, they were a lot more interested in telling all about the technical nitty gritty than we typically see now.  Though the reporters ask pretty much the questions most users are still interested in, when will you start making it, what colors will it come in, how much will it cost? 

The rather negative reaction to the look of the phone was also interesting to read about.  Seems that the look of the new unit was not very popular at first glance and that it took time to win people over.  That's kinda how I've felt about the 500 series myself, and it's children the 1500 and 2500, for years and years I just thought they were pretty pedestrian designs and boring, it's only been since collecting them and really starting to pay attention to the design that it's grown on me.