The EICO Model 667 Dynamic Conductance Tube & Transistor
Tester is one of the first thoroughly practical service
instruments able to test both tubes and transistors. Among
its advantages are rapid and simple operation, close
simulation of actual tube operating conditions, and
unexcelled thoroughness and accuracy of test. The
outstanding mechanical design and layout, coupled with
components carefully selected for ruggedness, makes the
Model 667 extremely well-suited for the hard usage of daily
All components of the Model 667 tube tester are assembled to
the heavy-gauge aluminum front panel, which is in turn
top-mounted by 14 screws to flanges on all four sides of the
steel case. A detachable steel cover is mounted to the back
of the case with separable hinges so that the cover may
easily be removed for use of the instrument as a counter-top
model or replaced to convert it back to a portable instrument.
There are ten different tube sockets on the panel to
accomodate modern receiving and other tube types (see Types
Tested below). In addition, pilot and Christmas tree lamps
can be checked rapidly using the center of the Novar socket.
A special transistor socket accomodates both n-p-n and p-n-p
transistors. To protect against damage due to current
overload, a type 3AG 1 ampere fuse is connected in series
with the primary of the power transformer.