'Ancient' WECo. D1s w/ 'Renaissance' Transmitters?

[Come in Nighthawk]

 

Forgive the historical "allusion" of "Ancient" and "Renaissance" to make my point?  In my defense, I'm an historian.  Here's the point.   I'm wondering if the transmitter was "the" part that wore out fastest (and/or more often) on W. E. B1 and D1 phones in the late 1920s and on into the 1930s??  My "unscientific survey" from the handful of phones I have acquired in my short sojourn in this hobby would suggest as much.  In every case, the transmitter is "younger" than the receiver, even allowing that the receiver usually isn't the same date as the mount, suggesting it had been replaced too (but not as often as the transmitter?). 

Here are a few examples from my tiny collection.  Please note the disparity in dated transmitters versus receivers, and the dates of the mounts:

B1 or D1?* ----- F1? ------ 557/557B?
B1 n.d. ------- 10/36 ----- Mar. 1929
D1 IV-34 ----- 5/40 ------ IV-37
B1 3/29 ------ 3/37 ------ 230 (Feb. '30?)
D1 II-31 --- June 31** -- III-36
D1 IV-31 ----- 1/37 ------ II-31

* All equipped w/ E1 handsets.  I have discounted the cpl D1 phones I have w/ F1 handsets.

** This D1 has an E1 handset equipped w/ a 395B "bullet" transmitter (which still works BTW!), and IMO helps illustrate my point?

Now, if I have this wrong, and am wasting everyone's time, JLMK!!    If I may be on the right track, I'd appreciate any info to that effect.  EITHER way, maybe this has been addressed in a published work?  I have Ralph Meyer's Old-Time Phones, but can find no mention of this "phenom" there...

Thanks in advance! 

[Phonesrfun]

Transmitters were very much prone to problems, especially before the T1 that was designed for the 500.  The F1 was specifically designed to overcome the problems of the older bullet transmitter, which was designed to overcome the problems of the older solid back transmitters from the candlestick and wood wall phone days.  All transmitters have the inherent problem of the carbon granuals packing together and even a little microscopic welding of the granuals together.  There is a scientific term for this welding effect, but it escapes me now.

The F1 and the T1 transmitters can be banged on a table top to loosen the packed carbon, and is a frequent fix, and even one that was used out in the field by installers.  The T1 is less prone to packing than the F1, due to the improved process of "roasting" the granuals before making the transmitter.

Other problematic things about the transmitter are vibration from hanging the phone up, moisture coming from the user's mouth, room humidity, temperature extremes and actually, I think the list goes on.

I have never seen any statistics about transmitter failure and replacement, but I am sure Bell Labs in conjunction with Western Electric probably had a handle on this as much as any organization would.  Given the Bell Lab Reports and Bell system Technical Journals that were always touting the new and improved ways that any given new transmitter design was better than the previous design, I would have to say that it was, indeed a problem situation for them.

That is also probably why, in the later model sets, the telephone transmitter is the one item in the telephone that just pops out when you loosen the cap.  It is by far the easiest item in the entire phone to replace.  Probably no accident.

[Come in Nighthawk]

Transmitters were very much prone to problems, especially before the T1 that was designed for the 500.  The F1 was specifically designed to overcome the problems of the older bullet transmitter, which was designed to overcome the problems of the older solid back transmitters from the candlestick and wood wall phone days. 

.......

That is also probably why, in the later model sets, the telephone transmitter is the one item in the telephone that just pops out when you loosen the cap.  It is by far the easiest item in the entire phone to replace.  Probably no accident.

Thanks Bill!!   

[rp2813]

I always had a feeling that the bullet type transmitters had a high failure rate.  They were also very clunky so no doubt there were various savings to be enjoyed by WECo once the F1 was introduced.  I think I read somewhere here a while back that at some point, a directive was issued to field techs to change out any bullet transmitters they came across with F1's. 

The "OCT 30" 395B on my D-1 was bad when I got it.  I opted to go for the F1 retrofit instead of another bullet.  It's good to know that based on your small sample, the 557's apparently performed well.  I may need to replace mine, as sound quality is hollow and squawky.

I only have the one E-1 handset phone so I can't say for sure, but I'm wondering if there is such a thing as a bullet transmitter with more than one date on it.  I have never seen or read about one.  On the other hand, I have F1's and T1's that have been tested and redeployed so many times that there's no room left for any more dates.   That could be another indicator of the overall performance record for the 395B.

[Come in Nighthawk]

........ On the other hand, I have F1's and T1's that have been tested and redeployed so many times that there's no room left for any more dates.   That could be another indicator of the overall performance record for the 395B.

I have a number of components in my tiny collection that seem to have a second date-stamp.  Usually the first is in red (like the dates in my table above), while the second is in yellow.  As a neophyte I first took these as a code as they usually take the form of three or four numbers ending in one or two letters.  From what I've read here in the forum I now believe these are "test" dates indicating a component, either shelf stock or recovered from a repossessed phone(?), had been evaluated and passed for issue?  They seem to be month/year (the latter expressed in two digits), and the letter or letters either indicate some code or maybe the city/plant the test was accomplished in?  I assume these secondary stamps come from a factory and not a linesmen/repairmen at a customer's residence or business?

[paul-f]

I have a number of components in my tiny collection that seem to have a second date-stamp.  Usually the first is in red (like the dates in my table above), while the second is in yellow.  As a neophyte I first took these as a code as they usually take the form of three or four numbers ending in one or two letters.  From what I've read here in the forum I now believe these are "test" dates indicating a component, either shelf stock or recovered from a repossessed phone(?), had been evaluated and passed for issue?  They seem to be month/year (the latter expressed in two digits), and the letter or letters either indicate some code or maybe the city/plant the test was accomplished in?  I assume these secondary stamps come from a factory and not a linesmen/repairmen at a customer's residence or business?

There are some notes on similar markings used on the 500-series sets here:
  http://www.paul-f.com/we500typ.htm#Date