In mahogany housing with ebonite
front and knobs nickeled brass
Advertisement for a tuning
capacitor by the company in Popular Electricity
from June 1913
The original price was about
Loose couplers were used in the '10s of the
The device consists of two coils, a primary and a secondary.
The primary coil is stationary and is equipped
with a compound switch with 34 (16 + 18) contacts so that the inductance of the coil
can be adjusted.
The secondary coil can be slid in and out of the
primary coil to vary the degree of coupling and is also equipped
with a slider and 12 contacts so that the inductance can
be changed there too. This model is also called "Navy type
By means of a "dead end switch", mouted on the
panel, the major part of the primary winding may be entirely
disconnected from the circuit when receiving on low wave
A loose coupler was the first tuning tool in an
The first coil was connected to an antenna and a ground;
the second coil was connected to a detector, in most cases a
crystal. Wave lengths
of 200-4000 meters may be tuned to.
John Y. Parke & Co.
made all kinds of technical articles as early as the 19th
The company was located in Philadelphia, 127 North 7th Street.
Dimenstions (h x w x d):
16.5 x 47 x 16.5 cm
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maandag 22 maart 2021