1934 F1 transmitter unit

[poplar1]

The F1 transmitter was developed for F-type handsets.  However, they were also used as part of the 625A transmitter on new E-type handsets, starting around 1935, or about 2 years before F-type handsets went into production.

Paul F.'s site confirms on the notes about the D-95647 that the F-1 transmitter unit was developed in 1934. This is the first one I've found older than 1935:

[paul-f]

That's a great find!

Thanks for sharing the photos.

[poplar1]

I asked the seller if he knew where he got this transmitter; here is his response:

"Yes, first one I've ever seen from 1934. 
Unfortunately, I don't remember what it came out of."