Field Trial "F" Numbers Question

[.....]

Since the posting of the contest for the WE 1959 DTMF F-53139 Field Trial Telephone I began to wonder about the "F" Number on the Field Trail phones.
The F stands for field, that much makes sense to me.
I took out my Field trial clear phone and compared the numbers.
Mine was made 6-58 with the number F-53115.
The eBay one is 11-58 with the number F-53139.
That makes a difference of 24 numbers over a 5 month period. 
My question is:  Can there be 24 sequential numbered field trial models out there between these two phones and what model would they be?
The other difference between these phones is mine has leather feet and the eBay one has plastic feet.
If anyone has a Field Trial phone with a different number and date please post it.

[Jim Stettler]

F-numbers show up on various items.  I have seen them on non-working display phones and also on Design-line conversion kits.
So I don't think they are always field trials.
They are on the early clear 500's. I think those are marketing sets.
I think the digits may have some meaning, like serial numbers
I kinda think the F sets were made in the Indy plant. This is just my impression and based on nothing documented.

Paul F.'s opinion on F#'s would be much more valid than my opinion.
Just musings and ramblings, no documentation,
Jim

[jsowers]

Paul Fassbender's site has a lot about Field Trial sets. Sadly, there is no master list of F numbers, or none that anyone has ever unearthed. They are consecutive, from what we can tell, but whoever kept the list didn't leave it to history. And as Jim said, they're on more than field trial sets.

Here is Paul's page on the touch-tone models: http://www.paul-f.com/weprotot.html
Rotary field trial sets and prototypes: http://www.paul-f.com/weproto.html

[paul-f]

This topic has been on my To Do list for years.

As has been pointed out, we have discussed several non-field-trial uses for F- numbers in the past. One good topic is here:   http://www.classicrotaryphones.com/forum/index.php?topic=16267.0

We even started collecting numbers for a list. As with many projects, as we got into it, we found many more numbers than expected. I had some health issues and the group drifted off to other projects before deciding on a format and sending a working list. Hopefully, we'll resurrect this effort some day.

We should at least put out a list of types of uses for F- numbers by category. If I have time over the weekend, I'll see if I can dig up my notes.

Some that come to mind include:

   
• Field Trial Sets
• Display Sets (no working internals)
• Display Sets (transparent, working)
• Parts for Customer-supplied Housings (e.g. F-58554)
• Limited Production Sets with BSPs (e.g. F-58554 Card Dialer, F-50682 Ground Observer's Set)

In addition, on my site are Field Trial and other engineering sample sets and parts with codes beginning with B-, D-, GA-, GN- and Y-.

[.....]

This topic has been on my To Do list for years.

As has been pointed out, we have discussed several non-field-trial uses for F- numbers in the past. One good topic is here:   http://www.classicrotaryphones.com/forum/index.php?topic=16267.0

We even started collecting numbers for a list. As with many projects, as we got into it, we found many more numbers than expected. I had some health issues and the group drifted off to other projects before deciding on a format and sending a working list. Hopefully, we'll resurrect this effort some day.

We should at least put out a list of types of uses for F- numbers by category. If I have time over the weekend, I'll see if I can dig up my notes.

Some that come to mind include:

   
• Field Trial Sets
• Display Sets (no working internals)
• Display Sets (transparent, working)
• Parts for Customer-supplied Housings (e.g. F-58554)
• Limited Production Sets with BSPs (e.g. F-58554 Card Dialer, F-50682 Ground Observer's Set)

In addition, on my site are Field Trial and other engineering sample sets and parts with codes beginning with B-, D-, GA-, GN- and Y-.

Thanks Paul for the information and link.

Sorry to hear about your health issues, I hope you're feeling better.

Doug

[paul-f]

Sorry to hear about your health issues, I hope you're feeling better.

Thanks Doug. The issues were resolved by surgery just over a year ago. Things have been good since.