Honeywell KHF 1050 System Installation Manual page 142

Squelch Type: The KHF 1050 System offers four types of squelch. If using a
controller that does not allow for the selection of the squelch type (i.e. does not
send ARINC 429 word 0), the squelch type established by this setting will
determine the squelch used by the KRX 1053 receiver. For example, the
Honeywell RM-855 RMU does not allow for the selection of the squelch type.
SBH is a syllabic squelch that is generally preferred for voice communications
and is the factory default setting. Other selections are SBL, SQL and SQH.
SBH - (Syllabic Squelch High). This is the default squelch and is usually best
for normal voice communications. A syllabic squelch opens upon receiving a
signal with voice-like characteristics while ignoring other signals. With syllabic
squelch, there is the possibility that the first syllable of a voice reception may be
partially squelched. The possible adjustment levels are open, meaning no
squelch action (OPN), minimum (MIN), medium (MED) and maximum (MAX).
SBL - (Syllabic Squelch Low). This squelch is also a syllabic squelch and is
intended for voice communications where the desired signal is very weak and
noisy. This squelch is more prone to opening on noise than the SBH squelch.
The possible adjustment levels are open (OPN), minimum (MIN), medium
(MED) and maximum (MAX).
SQH - (Signal/Noise Squelch High). This is a traditional signal-to-noise squelch
best suited for listening to non-voice signals, or voice signals that do not
respond well to one of the syllabic squelches. Compared to the syllabic
squelches, a higher signal level is generally required for this squelch to perform
well. The possible adjustment levels are 1-32, where 1 is open squelch.
SQL - (Signal Level Squelch). This is a signal strength squelch which opens on
any strong input signal. It opens quickly on strong signals, but also opens on
strong noise or static. Use of SQL is recommended for use only with strong
signals and under low noise conditions.
Revison 2
N
KHF 1050 SYSTEM INSTALLATION MANUAL
Sidetone Audio Level Relative to the
Value
Received Signal Level (approximate)
255
180
128
64
32
0
Table 2009 - Sidetone Audio Levels
0 dB
-3 dB
-6 dB
-12 dB
-18 dB
-30 dB
23-10-09
Page 2060
Apr/2006