Philips 7927 Phonometer


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 tube.
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.
Serial number: 2485
Dimensions: 16.7 x 11.8 x 6.2 cm
Made in: 1937
Voltages: via radio
Purhased in: 2017

User Manual

A look inside

The closed box

Type plate
Engelse folder uit 1938

Deze pagina is voor het laatst bijgewerkt op dinsdag 09 februari 2021