Questions about Early Dictograph Intercoms

[Rexophone]

Hi,

I'm new to the forum and am trying to find some information about my latest collecting fascination.  I've recently become interested in the earlier (pre-handset) Dictograph intercoms.  I bought a British mahogany substation and a box of four American made six-key stations in oak.  I was sad that the four oak units didn't have the distinctive Dictograph shield over the black microphone.  I read on Bob Estreich's website that "most" had the shield.  I guess that means a few did not?  After discovering how hard these units are to disassemble, I'm pretty sure the shields were not harvested from mine.  Does that seem right?

I also have found reference on the web for two promotional documents from 1912 and 1915: "The Dictograph--No Switchboard, No Operator, No Waiting" and "Thirty Minutes per Day per Man." I don't see that these have been scanned and are available anywhere. Does anyone have any pre-1920 Dictograph literature that could help me identify and understand my units better?

I would like to connect two or three of mine up and use them.  Does anyone have wiring diagrams for these animals?  What voltage do they work at?  The mic and earpiece seem to function at 3-4 volts.  The larger units have switchboard-style push-in indicator bulbs.  What voltage are those?  The bulbs are in series with a buzzer which seems to work well by iteself with about 3-4 volts.

As far as wiring, I've traced out both my little substation as well as the six-key units. The larger units are rather elaborate. They can set up (and seemingly patch) up to seven of the substations as well as three "master" units. The keys for the master units use a much more elaborate contact setup and have lights to indicate which station is calling.  The terminal board for the larger units have the pair for each substation numbered, plus the "master" station pairs are marked "M."  There is a pair marked "T" as well as another labeled "L" and another "R."  Are these like the regular line, tip, and ring of a regular phone system?  I'm not sure they are since each refers to a pair on the Dictograph.  There is also one terminal marked "Z."  Z appears to  provide local power for the buzzer (each unit has a relay to drive the buzzer).  I'm also beginning to sort through the schematics that were included with Dictograph patents from 1907-1910.

I would enjoy and appreciate any information, pictures, or stories about similar units.

Thanks!

Steve

[paul-f]

Welcome to the forum, Steve.

This is a great topic.  We've had a few discussions about Dictographs, but so far I haven't seen much documentation on them.  I hope some comes forward.

I haven't gone out of my way to find any, but have collected some photos and a few sets over the years.  Studying them in detail hasn't made it to the top of the project list yet.

Here are a few of the photos.

[Rexophone]

Thanks for the pictures Paul!  I particularly like seeing the inside of one of the master units that has a horn.  I was curious just how those looked.  I wonder if the later units with the lightning bolt grills were horns too or a more modern speaker.

Steve

[paul-f]

You're welcome, Steve.

Sorry for the delay.  I just got back from a week-long trip with a group that visited telephone museums and collectors on the way to the Lancaster show.

Here are a few more photos, including one with a speaker.

[Rexophone]

Thanks Paul!  I appreciate the additional pictures.  Helps me understand how these evolved.  By the way, I restored two of the larger units I bought in the group of four pictured at the top of this topic.  I noticed that there were tiny tacks in the back side of the microphone hole--so it seems that mine did originally have brass Dictograph shields over the mics.  They hadn't been taken apart recently, so I assume a collector didn't remove the shields.  I wonder why a user would have had them removed?

Steve