ID:
1889
Maker's Name:
Unknown
Where made:
England
Dimensions:
7 × 7 × 14 cm
Fine resistance wire is wound on a mica former. There are 4 wires in all, connected in series-parallel to form a centre-tapped wire-wound resistor. The wires are wound in two pairs, each pair being wound in anti-phase, so there is nearly zero inductance. Total resistance is a little over 18 Ohms, ie one quarter of 72 Ohms, the nominal feed resistance of a free-space dipole antenna at its natural resonant frequency.
Book reference:
ARRL Handbook 1944
