Radiola 25
REG. U.S. PAT. Off.
Super-Heterodyne
INTRODUCTION
RADIOLA
25
is a radio broadcast receiving instrument, utilizing the
super-heterodyne principle, which provides unusual simplicity of
operation, selectivity and sensitivity. The cabinet contains the operating
mechanism and battery equipment, as well as a socket for the loop
antenna which is plugged in through a hole in the top cover, making the
receiver self-contained, with the exception of the Loudspeaker. The
receiver is designed for reception over the broadcast frequency band,
550 to 1360 kilocycles (approximately 550 to
220
meters).
GENERAL
Radiola 25 Super-Heterodyne "A," "B" and "C" supply may be
obtained as described in any one of the following combinations:
1. Complete dry battery operation, in which the "A," "B" and "C"
supply is obtained from dry batteries. This is the form in which
Radiola
25
is normally supplied.
2. "B” voltage may be obtained from either the
RCA
Duo-Rectron,
Model AP-937, or Radiola Loudspeaker, Model 104, the "A"
and "C" supply being obtained from the usual dry batteries.
(a)
R.C.A. Duo-Rectron, Model AP-937 is operated from an al-
ternating-current circuit rated at 105 to 120 volts, 40 to 60
cycles.
(b) Radiola Loudspeaker Model 104 may be operated from an
alternating-current circuit rated at 105 to 120 volts, either
40 to 45 cycles or 50 to 60 cycles.
3. "A," "B" and "C" supply may be obtained from Radiola
Loudspeaker Model 104 (making Radiola
25
entirely operated
from alternating current), by changing Radiola
25
so as to
employ the accessories furnished in the AC Package, Model
UP-971.
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