Section
IV
Paragraphs 4-11 to 4-14
L1508, in the r-f chassis. Powdered iron cores, fas-
tened to the slug rack, are moved in or out of the r-f
22.125 mc, is passed by the tuned circuit T1501 which
coils in steps of approximately .015 inch for each
will reject all other frequencies. The output from
megacycle change in the setting of the outer knob.
T1501 is fed to r-f mixer V1503. Trimmer capacitor
Thus the tuning of L1506 and L1508 is automatically
C1534 adjusts the frequency of the coarse frequency
varied in approximately one-megacycle steps and
oscillator for all 28 crystals. Trimmers C1539 and
L1503, L1504, L1505, L1510 and L1511 in approxi-
C 1542 are used to adjust T1501 at the upper frequency
mately 250-kc steps to maintain proper tracking as
limit.
the signal generator frequency is varied in one-mega-
cycle steps.
(See figure 4-5.)
NOTE
the fine and coarse frequency oscillators V1501 and
The band pass of the following tuned r-f stages
V1502. The output of V1501, 4.875 to 5.100 mc in 10
is sufficiently wide so that no retuning of the
steps of 25 kc each, is coupled through C1507 and fed
slug rack is necessary over the megacycle
to the grid of r-f mixer V1503. The output of V1502,
spread represented by the fine frequency os-
22.125 to 28.875 mc in 28 steps of 250 kc each, is
cillator V1501.
coupled through C 1508 to the grid of V1503. The two
