Kenwood TS-700A Operating Manual page 13

Next, set the METER switch to the S position and the
meter will indicate the strength of the incoming signal. If, in
this case, the meter pointer fluctuates in response to the
sound in the speaker, turn the MAIN dial a little (a few kHz)
in either direction until the meter indication is stabilized
(meter is stabilized if no fading exists).
Since the TS-700A is so designed that the IF circuit for
SSB forms a part of the S" meter indication circuit for FM,
the "S" provides logarithmic indications for FM waves and is
free from saturation even when the input signal strength is
very high, thus eliminating the need for calibration for each
mode of operation.
Since the IF band is wide in FM mode, a slight devia-
tion of frequency does not affect the reception. In transmit-
ting operation, however, the other party could be using a fix-
ed channel. Because of this possibility, it is advisable that
you "zero in" your frequency to that of the other party by
properly adjusting the MAIN dial in the manner that the
center meter pointer may deflect up to the center space.
If the 'S" meter continues to fluctuate or if satisfactory
audio output is not available, it is very likely that the other
party is sending the message on SSB. You can easily check
this by turning the MODE switch to USB or LSB position.
SSB Mode
Of the single sideband mode, USB is traditionally more
often used than LSB. As far as the operating technique is
concerned, there is no difference between two.
Generally, the "zero in" technique in SSB mode re-
quires a little experience.
A. Discrimination between SSB and FM
(1) Use of "S" Meter
If the S" meter indication is steady (meter pointer almost
stops), the incoming signal is FM; otherwise, it is SSB.
(2) Use of MODE Switch
If a clear signal is heard at the FM position of the MODE
switch, the signal is FM. The sound in SSB mode is not
heard at this position of the switch
(3) Use of Beat Noise
In FM mode, a beat noise will be heard between the words
of signals being received. In SSB mode, no beat noise is
heard.
Note: In the case of AM waves, a beat noise will be heard
during non-modulation time even in SSB mode.
B. Dial Setting
When the receiving signal is found to be SSB by the
above method A, in USB first set the MAIN dial a few kHz
below the receiving frequency (turn the dial 2 or 3 divisions
counterclockwise). You will hear a high pitch sound such as
is heard from a magnetic recording tape set in the fast-
forward mode. Turn the dial clockwise for higher frequency
and the sound will become clearer. Set the dial at the posi-
tion where the sound is heard most clearly (this is the "zero
in" point).
Note: 1 The "zero in' point can be easily located because
the sound loses its clarity suddenly when the dial
passes away from the "zero in" point.
If a clear sound cannot be heard even by following the
above procedure, it may be an indication that the signal is
LSB. Set the MODE switch to LSB position. In this case,
the method of setting the MAIN dial should be performed in
reverse order.
Note: 1. If the frequency of the other party is deviated after
the "zero in" point has been obtained, set the RIT
switch to ON and adjust the RIT knob.
2. When the RIT feature is used, the receiving fre-
quency will be deviated from the transmitting fre-
quency. Therefore, the RIT knob must be set to
"O" or the RIT switch to OFF before you start to
transmit again.
AM Mode
AM waves cannot be demodulated in FM mode; also,
they will be heard as a continuous beat noise in SSB mode.
Optimum reception of AM signal is secured by tuning the
transceiver in such a way as to maximize the deflection of
the "S" meter pointer. Since the bandwidth of the receiver
crystal filter is somewhat narrow because this filter is
primarily for SSB reception, the sound output of the speaker
may have its high pitch components suppressed and hence
lack clarity. This can be remedied by shifting the receive
frequency a little by using the RIT knob. The same effect
can be produced by means of the MAIN dial but the use of
this dial for that purpose is not recommendable because,
should you do so, you will not be able to "zero in" your
transmit frequency to the frequency of the other party.
Where your transceiver and that of the other party are
both TS-700A, it should be noted that, in AM mode, the
transmit carrier frequency is 10.7006 MHz which is higher
than the receive carrier frequency by 600 Hz.
Accordingly, you first 'zero in' your frequency to that
of the other party by adjusting your MAIN dial and send out
the signal, to which the other party will respond after
possibly changing his frequency. If he should do so, the
pointer of your "'S" meter then would deflect down from the
initial maximum level indication; this drop must not be in-
terpreted as a sign of trouble. In such a case, you are ex-
pected to re-match your frequency to the new incoming
frequency by using your RIT knob with the RIT switch set to
ON (refer to Fig 5 on page 14.)
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