A short time ago there was a discussion about the different EMs RCA produced and when they were produced. The other day I was digging through
my files and came across a copy of the August 1967 issue of the RCA
Scientific Instruments News which has pictures of all the models produced
and the year of introduction:
EMA 1939 I don't think this model was ever sold commercially. I believe it was built in the RCA Labs for developmental uses
EMB 1940 This was the first commercial model
EMC 1944 This model had a horizontal column
EMT 1950 This was an inexpensive table model that was designed with
use in high schools and small colleges in mind.. As I recall
it had lenses made of permenant magnets to eliminate the need
for lens power supplies and to hold the cost down.
EMU 1944 This was probably RCA's most popular model. It was on their
leading EM for at least 10 years.
EMD 1948 This was an electron diffraction instrument, designed specifically for obtaining ED patterns by the reflection from
solid surfaces at a grazing incidence.
EML 1954 This was the forerunner of the popular EM-U# and EM-U4 models,
but provided an accelerating voltage of only 50kV. It was the model in which RCA pioneered the modern ergonomic layout
of controls, with a desk-like design.
EMU-3 1955 Similar in appearance to the EML, but providing 100 kV.
EMU-4 1966 A refinement of the EMU-3, providing a double condenser lens,
a specimen stage airlock system, etc.
RCA ceased marketing electron microscopes in 1969. I was President of the EMSA that year and discussed the matter with James Hillier, one of the
pioneers in the field of electron microscopy, and a Vice President of RCA
at that time. He said that it was determined that RCA could make more
money selling records and related electronic devices than EMs, and so was
phasing out of the EM business.
The issue of RCA Scientific Instruments News in question also has a picture
of each model on the cover. I have had a copy run off in jpg format.
Wilbur C. Bigelow, Prof. Emeritus
Materials Sci. & Engr., University of Michigan
Ann Arbor, MI 48109-2136 e-mail: firstname.lastname@example.org;
See the RCA
EMT tabletop electron microscope!