Calibration Of Internal Reference Frequency - Kenwood TS-890S Instruction Manual

17 MAINTENANCE AND ADJUSTMENT

Calibration of Internal Reference Frequency

The internal reference frequency of this transceiver is preadjusted
at the factory. However, if calibration of the internal reference
frequency is necessary due to changes over time or other reasons,
this can be done by receiving WWVH (Hawaii), WWV (Colorado),
BPM (Xi'an) or other types of standard radio wave.
First of all, follow the steps below to set this transceiver to the mode
for receiving the standard radio wave signals. The following is an
example of the calibration procedure when the pitch frequency is
700 Hz.
1 Press [CW/ CW-R] to select CW mode.
2 Press [RIT] to turn off the RIT function.
3 Press [VOX] to turn off break-in.
• If semi break-in is turned on, press [VOX] to turn it off.
• If full break-in is turned on, turn the [DELAY] control to select
a value other than full break-in.
4 Turn the [AF] control to move to the 12 o'clock
position.
5 Turn the [MIC/PITCH] control to adjust the pitch to
a level for easy listening.
Turn the [MIC/PITCH] control until the pitch frequency reading
shows "700".
6 Turn the [LO/WIDTH] and [HI/SHIFT] controls.
Turn the [HI/SHIFT] control until the shift frequency (SHIFT)
becomes "0", followed by turning the [LO/WIDTH] control to
adjust the bandwidth (WIDTH) to "1000".
For details on the REF I/O connector settings, please
●
refer to "Switching the Reference
Calibration Procedure
Once the preparation is complete, follow the steps below to
configure the internal reference frequency of this transceiver.
1 Receive the standard radio wave signals.
To receive 10 MHz standard radio wave signals, turn the
Tuning control to adjust the value to exactly "10.000.00".
A 700 Hz beat is heard.
f
display [MHz]
f = x
AF
19.2
[MHz]
f
reference
.
Adjust such that the received beat is audible on the CW pitch
frequency.
2 Press [MENU].
17-2
Signal" (16-8).
f + 700
reference [Hz]
Reference Frequency Shift
3 Press F [ADV.] to display the Advanced Menu
screen.
• If F [ADV.] is not displayed, press F [MORE] to display F
[ADV.].
4 Select Advanced Menu [5] "Reference Oscillator
Calibration".
5 Press F4 [SELECT].
.
6 Press F7 [CAL.T].
A 700 Hz calibration sidetone is generated. This sidetone
overlaps with the RX audio and a double beat is formed by the
difference in frequency.
If the double beat is not clearly audible, turn the [AF] control to
adjust the RX audio.
f = 700
sidetone [Hz]
.
7 Press the F4 [–]/ F5 [+] or turn the [MULTI/CH]
control.
• Perform adjustment until the cycle of the double beat
between the RX beat and sidetone reaches the maximum
and the double beat is no longer audible. At this point, the
difference in frequency between the RX audio and sidetone
is at the minimum level.
• To restore the default setting, press and hold F2 [(RESET)].
8 Release F7 [CAL.T].
9 Press [ESC] to end the process.
If the signal used for calibration falls outside the range of
●
the reference signal input from an external source
(-10 dBm to +10 dBm) or frequency accuracy (10 MHz
±10 ppm), the internal reference frequency may not be
calibrated correctly.
‒ +
‒ +
8 (700 0.006 )
[ppm]
[Hz]