Circuit Description; Schematic Diagram; Frequency Chart - Heathkit SB-401 Assembly Manual

Page 125
HEA.TH~l:.T®
Frequencies In Megahertz
BAND CARRIER LMO
BANDPASS
HETERODYNE HETERODYNE
GENERATOR (BETWEEN COUPLER OSCILLATOR
MIXER OR
OUTPUT
5 AND 5.5)
FREQUENCY FREQUENCY TRANSMITTED
CRYSTAL
(BETWEEN (CRYSTAL
SIGNAL
FILTER
8.395 AND
FIXED) FREQUENCY
(FIXED)
8.895)
3.5 to 4 3.395
5.105 8.5
12.395
3.895
7 to 7.5 3.395 5.3 8.695
15.895 7.2
14 to 14.5
3.395 5.3
8.695 22.895
14.2
21 to 21.5 3.395 5.2
8.595
29.895
21.3
28 to 28.5 3.395 5.4 8.795
36.895 28.1
28.5 to 29
3.395 5.3
8.695
37.395
28.7
29 to 29.5 3.395
5.3
8.695
37.895 29.2
29.5
to
30 3.395
5.4
8.795
38.395 29.6
FREQUENCY CHART
To make the various functions of the Transmitter
easier to understand, a selected lower sideband
frequency of 3.895 megahertz will be used when
tracing through the circuit in this Description.
All switches are shown in their fully counter-
clockwise positions on the Schematic. The Fre-
quency Chart Iiststhe various frequencies that
will be found throughout the Transmitter. The
first line contains the frequencies referred to
in this Circuit Description.
The letter-number designations on the Schematic
Diagram are used to identify resistors, capac-
itors, chokes, etc. Each of these designations is
related by the first number to the physical place-
ment of the part in the unit. For example, resis-
tors (and other parts) mounted on the carrier
generator circuit board are designated by num-
bers in a series of 100 to 199, while parts
mounted on
the
chassis are
in
a series
from
1 to 99. This system of component designation
FREQUENCY CHART
SCHEMATIC DIAGRAM
is used throughout
the
Schematic. Read the
NOTES on the Schematic for further infor-
mation.
Refer to the Schematic (fold-out from Page 147)
and the Block Diagram (fold-out from Page 124)
while reading the Circuit Description.
CIRCUIT DESCRIPTI