Icom HF/VHF/UHF ALL MODE TRANSCEIVER TV Receiver User Manual


 
21
4
RECEIVE AND TRANSMIT
D Noise blanker
The
noise blanker
reduces pulse-type noise such as
that generated by automobile ignition systems. This
function is not effective for FM modes or for non pulse-
type noise. If you don’t want to use the noise blanker
for AM communications, the “AM noise blanker” item
in Initial Set mode must be turned OFF (ON is the
default setting—p. 53).
Select M3.
•Push [DISPLAY] 1 or 2 times when S or G is displayed.
•Push [MENU] one or more times to select M3.
Push [(F-2)NB] to toggle the noise blanker ON and
OFF.
•“NB” appears when the noise blanker is turned ON.
NB
CH
VFO A
S1
5379204060dB
USB
M3
NAR
NB
MET
Appears when the
noise blanker is
turned ON.
PO 5
10
D AGC time constant
The
AGC
(Automatic Gain Control) controls receiver
gain to produce a constant audio output level even
when the received signal strength is varied by fading,
etc. Use AGC slow for normal phone operation; AGC
fast for receiving data and searching for signals. AGC
time constant cannot be changed in FM mode.
Select M4.
•Push [DISPLAY] 1 or 2 times when S or G is displayed.
•Push [MENU] one or more times to select M4.
Push [(F-3)AGC] to toggle the AGC time constant
between fast and slow.
•“FAGC” appears when the fast time constant is selected.
CH
VFO A
S1
5379204060dB
USB
M4
VOX
COM
AGC
Appears when
AGC fast is
selected.
FAGC
PO 5
10
D Preamp and attenuator
The
preamp
amplifies received signals in the front
end circuit to improve the S/N ratio and sensitivity.
Turn this function ON when receiving weak signals.
The
attenuator
prevents desired signals from distort-
ing when very strong signals are near the desired fre-
quency or when very strong electric fields, such as
from broadcasting stations, are near your location.
Push [P.AMP/ATT] momentarily to turn the preamp ON
and OFF; push and hold to turn the attenuator ON.
•Lights green when the preamp is ON; lights red when
the 20 dB attenuator is ON.
•Only one of these functions can be activated at a time.
P.AMP/ATT
Lights green while the preamp is activated;
lights red while the attenuator is activated.
D Peak meter hold
The peak meter hold function freezes the highest dis-
played bar segment in any meter function for about
0.5 sec. so that you can more easily read the meter.
This function can be turned ON and OFF in initial set
mode (see p. 51).
INITIAL SET MODE
S1
5379204060dB
S1
5379204060dB
Initial reception of a
signal results in an S-
meter reading of 40
dB.
The highest indicated
bar remains displayed
for about 0.5 sec.
even when the signal
strength decreases.
[EXAMPLE]: