D Convenient Functions For Receive; D About Bpsk And Qpsk Mode - Icom IC-7800 Instruction Manual

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RECEIVE AND TRANSMIT

D Convenient functions for receive

• Preamp (p. 5-9)
➥ Push [P.AMP] several times to set the preamp
OFF, preamp 1 ON or preamp 2 ON.
• "P.AMP1" or "P.AMP2" appears when the preamp 1 or
preamp 2 is set to ON, respectively. (depending on
operating frequency band)
• Attenuator (p. 5-9)
➥ Push [ATT] several times to set the attenuator in
6 dB steps.
• Pushing [P.AMP] for 1 sec. to set the attenuator in
3 dB steps.
• "ATT" and attenuation level appear when the attenu-
ator is set to ON.
• Noise blanker (p. 5-17)
➥ Push [NB] switch to turn the noise blanker ON
and OFF, and then rotate [NB] control to adjust
the threshold level.
• Noise blanker indicator (above [NB] switch) lights
when the noise blanker is set to ON.
• Push [NB] for 1 sec. to enter noise blanker set mode.
• Twin PBT (passband tuning) (p. 5-12)
➥ Rotate [TWIN PBT] controls (inner/outer).
• Push [PBT CLEAR] to clear the settings.

D About BPSK and QPSK mode

[F-1•<MENU1>] [F-2•B/QPSK]
• PSK decode screen— BPSK mode
• PSK decode screen— QPSK mode
[F-3•DECODE]
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• Noise reduction (p. 5-18)
➥ Push [NR] switch to turn the noise reduction ON
and OFF.
• Rotate [NR] control to adjust the noise reduction
level.
• Noise reduction indicator (above [NR] switch) lights
when the noise reduction is set to ON.
• AGC (auto gain control) (p. 5-11)
➥ Push [AGC] switch several times to select
AGC FAST, AGC MID or AGC SLOW.
➥ Push [AGC VR] to turn the AGC time constant
manual setting ON and OFF.
• Rotate [AGC] control to adjust the time constant.
• Fine tuning (p. 3-7)
➥ During no kHz tuning step function OFF (no "Z"
indication), push [TS] for 1 sec.
• May not be decoded correctly with the 10 Hz step
tuning.
• 1 ⁄ function (p. 3-6)
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➥ Push [1/4] to turn the
BPSK and QPSK modes are available for the PSK31.
• BPSK (Binary Phase Shift Keying) mode is the most
often used mode.
• QPSK (Quadrature Phase Shift Keying) mode has
error correction capability to provides a better decod-
ing than BPSK mode operation even in a worth con-
dition. However, much accurate tuning is required
with the QPSK mode, due to the QPSK mode has
only few phase margin.
q During PSK mode selection, push [F-3•DECODE]
to display the PSK decode screen.
w Push [F-1•<MENU1>] to select PSK decode menu
2.
e Push [F-2•B/QPSK] to toggle between BPSK and
QPSK mode alternately.
1 ⁄ function ON and OFF.
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