[Test-Equipment] Triplett 310 dating Was Triplett 310 leads

[k4pf at juno.com]

> Barry <n4buq at knology.net> wrote
<snip
This brings me to wonder if I have a different version 
of the Model 10 and, even more so, which version of the 310 I have.  
I understand there are a few(?) different versions but 
I cannot see anything in the 310 or the 10 that indicates 
which version those are.  That leads me to think 
that they both are the original versions but I don't have anything 
to back that up. <snip>

Hi, Barry

Sorry that I missed your posting earlier.
I have several Triplett 310's, the earliest being a type 2
(written on the panel meter just below the model number).
It requires 4 screws to be removed to get access
to the battery compartment.  The newer series 310's
have a slide latch that allows removal of the battery compartment
cover without tools.

Another improvement was changing the range switch to a top-side
position, so there would no slot needed at the bottom of the front
panel for the range switch to travel. (The previous design allowed
dust to enter the instrument.)  My type 3 has the old style range
switch, my type 5 has the newer design.

The first model 310 came out in 1955.  The model 310C added
a polarity reversing switch on the side.

73,
Ed Knobloch