Portable tube tester for comparing two tubes of
the same type
In black wrinkled lacquer finished metal box with
hinged lid and brown leather carrying strap.
With this instrument, a tube vendor could convince
a consumer that a new tube sounds better than an old, worn-out
The tester is equipped with an adapter that can
be inserted into a tube base in the radio of a customer.In the tester, a new tube and the old tube from the
customer's receiver were placed side by side.By switching a lever, the quality
difference between the old and the new tube could be proved in
an audible manner.
A two-pin plug has to be inserted in
the positions "S" (for valves with series-connected filaments,
DC and AC/DC receivers) and "P" (for valves with
parallel-connected filaments, AC receivers).
Tubes with a B-base and a P-base can be tested. The test
does have some restrictions. Testing HF converter and other
preamplifier tubes works less well because of capacity
differences. The Phonometer
was specially designed for power tubes and rectifiers.
The original price was NLG 9.50, including a pair
of adapter sleeves.