*FantasticTubes !!!

*

One tube, circa 19??, U.S.A made by Raytheon,
type OA3 / OA3A vacuum tube
as pictured.

Condition:
New Old Stock / New In Box

Hickok TV-7B/U* tested 

*Hickok TV-7B/U is a mutual conductance(Gm) type tube tester. It does check for mutual conductance which is a more accurate measure of tube's age.

Satisfaction Guaranteed!
*FantasticTubes!!!