Receiver - Codan NGT 2010 RF Technical & Service Manual

NGT—Overview and specifications

Receiver

Table 2: Receiver specifications
Item
Type
IF frequencies
Sensitivity
Input protection
Selectivity
Desensitisation
Blocking
Image rejection
Spurious responses
Intermodulation
AGC
38
Specification
Dual conversion, superheterodyne
45 MHz and 455 kHz
Frequency:
0.25 to 30 MHz
Frequency:
1.6 to 30 MHz
For 10 dB SINAD with greater than 50 mW audio output
Will withstand 50 V p–p RF from a 50 W source
Greater than 65 [70] dB at –1 kHz and +4 kHz reference SCF USB
Pass Band:
Ripple:
10 dB SINAD reduced to 7 dB SINAD
−1 and +4 kHz (ref SCF) 60 [65] dB
±10 kHz
±50 kHz
As for Desensitisation
For frequencies > ±50 kHz > 95 dB
Better than 65 [70] dB
Better than 70 [90] dB
Self-generated signals > 0.15 mV PD: 4.999, 29.49 MHz
To produce a third order intermodulation product equivalent to a wanted signal
producing 10 dB SINAD, two unwanted signals greater than 30 kHz removed
from the wanted signal must have a level greater than 90 [92] dB above the
wanted signal
Third order intercept (unaffected by AGC):
+30 [+33] dBm with RF amp off
+10 [+13] dBm with RF amp on
Less than 6 dB variation in output for input variation between 2.0 [1.0] µV and
100 mV PD (RF amp on)
Fast attack, slow release (selectable release time)
RF amp off:
1.5 [1.25] µV PD
–103 [–105] dBm
RF amp on:
0.2 [0.12] µV PD
–121 [–125] dBm
–8 [–6] dB
4 [2] dB p–p
75 [80] dB
90 [95] dB
NGT Transceiver System Technical Service Manual
300 to 2800 Hz
500 to 2700 Hz