In MMD 010415, Keith Rogers wrote:

> I am trying to find information on converting an Edison
> Dictaphone to play either 2-minute or 4-minute cylinders.

Hello Keith:  Edison was careful to make his office machines
incompatible with the normal domestic cylinder phonographs.  The
2-minute machine plays records with a 100 threads-per-inch (tpi)
pitch while the 4 minute record plays records with a 200 tpi pitch.

The sizes of the elliptical styli were .008" radius and .004" radius
respectively to play these two speeds.  The Edison Ediphone (Dictaphone
was another competing brand name) had a stylus diameter of .006" and
thus nothing is compatible.  Edison did provide some ingenious gear
change mechanisms for the 2-4 minute phonographs and some of the
reproducers even had styli selectors but no kits were issued to
convert the business machines.

The odd gear ratio and the sometimes strange recorder reproducer
position and mounting was deliberate and I have never in 40 years
of collecting Edisons seen such a conversion.

If you want to play 2- and 4-minute records I would advise an Edison
Fireside, Standard, or Home be found that is equipped with the gear
change mechanism along with a reproducer that will play both speeds or
two reproducers.  You see a lot going on eBay but I would rather find
a local machine I could see with my own eyes and hear with my own ears
that is not a kitchen table put-together.

For years a Santa Barbara collector sold "dual" speed styli taken from
old Ediphones which are still damaging records to this day.  Make sure
you read up on Edisons before you invest in them.  I would recommend
"The Edison Cylinder Phonographs" by Frow and Sefl (out of print) or
the expanded "The Edison Phonograph Companion" by Frow which is still
in print.

I am the only collector in the world that I know of to have all of
the Edison domestic cylinder phonograph models.  It took me 40 years
to amass the collection and I have seen some ingenious fake rare models
and some phonographs that could best be described as mongrel.  Arm
yourself with information first before you buy anything like an Edison
Ediphone.

As a fairly good machinist I wouldn't want to spend the time cutting
the gears and designing some sort of planetary transmission that would
allow the playing of domestic records.  An Edison 2-4 Fireside or Home
would be more cost effective in the long run.  Besides, you will love
having to crank up a spring motor machine and can watch the fly-ball
governor in operation, something you cannot do with the Ediphone
Business Phonograph.

Al Sefl - Also an old crank...