*FantasticTubes !!!
*
One matched pair, circa 1950s, U.S.A made by Tung-Sol,
type 5687 vacuum tubes
as pictured.
Silk-Screening:
nil
Acid Etched Designations (Tung-Sol's emblems):
5687 / 3
5687 / 3
Painted Designations:
nil
nil
Date Codes:
n/a
n/a
Tubes feature black plates, copper grids and top-mounted 'Horse-Shoe' shape getters construction.
Tubes appear identical in construction.
*
Hickok TV-7B/U* tested
@ 82/87 85/90
minimum acceptable value for a good tube:
38/38
(Triode#1 / Triode #2)
*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 !!!