NRD-545 | JRC

JRC » NRD-545

Triple-conversion HF desktop receiver with last IF in digital technology. Frequency range 0.1-30 MHz, all-mode, digital noise reduction (DNR), pass-band shift (PBS). Ideated in Japan.

Reference market : ham-radio

General :
Frequency coverage 0.1000 ~ 29.9999 MHz
30.0000 ~ 2000.0000 MHz [1]
Modulation mode CW / RTTY / LSB / USB / AM / AM-S / FM / WFM [1]
Tuning step 1 / 10 / 100 Hz / 1 / 5 / 6.25 / 9 / 10 / 12.5 / 20 / 25 / 30 / 50 / 100 KHz
Receiver :
Sensitivity CW / SSB 5.0 uV (0.1~0.5 MHz, 10dB S/N)
2.0 uV (0.5~1.6 MHz, 10dB S/N)
0.32 uV (1.6~30 MHz, 10dB S/N)
RTTY 5.0 uV (0.1~0.5 MHz, 10dB S/N)
2.0 uV (0.5~1.6 MHz, 10dB S/N)
0.32 uV (1.6~30 MHz, 10dB S/N)
AM 15.8 uV (0.1~0.5 MHz, 10dB S/N)
6.3 uV (0.5~1.6 MHz, 10dB S/N)
2.0 uV (1.6~30 MHz, 10dB S/N)
3.2 uV (30~1000, 10dB S/N) [1]
3.2 uV (1260~1300, 10dB S/N) [1]
FM 0.5 uV (1.6~30 MHz, 12dB SINAD)
0.8 uV (30~1000 MHz, 12dB SINAD) [1]
0.8 uV (1260~1300 MHz, 12dB SINAD) [1]
WFM 2.0 uV (30~1000 MHz, 12dB SINAD) [1]
Selectivity CW 0.01~9.99 KHz (-6dB)
> 1.0 KHz (-6dB) [2]
< 4.0 KHz (-60dB) [2]
SSB 0.01~9.99 KHz (-6dB)
> 2.4 KHz (-6dB) [2]
< 5.0 KHz (-60dB) [2]
AM 0.01~9.99 KHz (-6dB)
> 4.5 KHz (-6dB) [2]
< 8.0 KHz (-60dB) [2]
FM > 10 KHz (-6dB)
RF attenuator 20 dB
IF-filter ultimate attenuation [4] 65 dB
Dynamic range 106 dB (0.3 KHz BW)
96 dB (100 KHz spaced signals) [4]
68 dB (5 KHz spaced signals) [4]
Blocking [4] 127 dB (100 KHz spaced signal)
IP3 (3rd order intercept point) +20 dBm (14 MHz)
Image rejection > 70dB
IF rejection > 70dB
AGC 0.04~5.1s adjustable
Frequency stability ± 10ppm max from 5' to 60' after warm-up
± 2ppm max after 60' warm-up
± 0.5ppm max [3]
Intermediate frequency 70.455 MHz
455.0 KHz
20.22 KHz
Features :
Memory 1000 regular memories
Display 10 Hz frequency resolution
40-segments signal meter bar
Antenna SO239 50Ω connector
Terminal jack 600Ω (0.1~1.6 MHz)
N 50Ω connector [1]
Power supply 12 ~ 16 VDC external, 13.8V nominal
100~240 VAC
Power consumption 30 W
Audio power 1 W with a 4Ω load
Audio output Jack 6.35 mm headphone
Jack 3.5 mm line
Jack external speaker
Connections RS232C PC
Jack timer
Jack mute
Jack VDC output
Mechanical and environmental data :
Dimensions 330 (W) x 130 (H) x 285 (D) mm
Weight 7.5kg

[1] With CHE-199 optional unit
[2] Values taken as reference, the bandwidth is continuously adjustable
[3] TCXO, CGD-197 optional unit
[4] This parameter, not in official data, was obtained with direct tests

Description :

The NRD-545 receiver is a hybrid technology device, adopting a triple frequency conversion analog configuration with the last IF which is digitized by an 18-bit sigma-delta ADC to be processed by a DSP in a purely numerical environment. It covers the band of 0.1~30 MHz in all operating modes, including the synchronous AM (ie the ECSS) and the RTTY for which there is a special demodulator. The frequency coverage can however be extended to the VHF / UHF using a special optional module that can be installed as a plug-in card directly on the internal motherboard, if already installed the model takes the code of NRD-545G operating seamlessly between 0.1~2000 MHz. Another version, the NRD-545U, for market reasons is characterized by operating on a series of non-contiguous segments that are 0.1~823.9 / 849.1~1849.9 / 1910.1~1929.9 and 1990.1~2000 MHz. Features : Tunable band-pass preselection RF filters made by a double resonant circuit controlled by varicap diodes. Front-end stage with preamplifier realized by a parallel of four FETs for a high linearity. IF filters freely adjustable between 0.01~9.99 KHz in steps of 10 Hz, PBS (pass-band-shift) to move the IF window of ±2.3 KHz in steps of 50 Hz, IF filter notch with minimum attenuation of 40 dB adjustable within ±2.5 KHz in steps of 10 Hz, notch-tracking function to keep the filter centered also by moving the tuning within ±10 KHz, automatic notch with intervention measurable in 256 steps, digital noise reduction function in 256 steps, double noise-blanker (NB) with intervention level adjustment, AGC time constant selectable between 40 ms (milliseconds) and 5.1 seconds in 20 ms steps, RF-gain for the regulation of gain in the RF and IF frequency chain, squelch, RF attenuator, audio tone control, clock with timer, output connection to activate a recorder, mute connection for pairing to a transceiver.

The tuning can be set using the central rotary knob, which takes advantage of an adjustable clutch, or with direct input from the keyboard or even remote PC management. The display shows each function including the S-meter which uses a series of segments on a graduated scale. There are 1000 memory locations in which is associated the AGC, the RF attenuator, the selectivity value, the eventual timer function. Search functions between limits of frequencies and between channels in memory with freely definable speed.

Performance and practical notes :

The JRC model NRD-545 was, at the time of its introduction in the 90s, one of the first receivers with DSP available for the amateur. It marked a positive turn by digitally implementing, among other things, the continuous filter bandwidth adjustment in the last IF and the adaptive noise reduction function. On the merits of the features the NRD545 shows the true lights and shadows, expresses some good overall performance with an excellent level of flexibility but suffers from a not yet mature DSP technology. This last point is highlighted with a form factor in the selectivity not exceptional and with a mediocre audio response. These aspects have led to a complex judgment, not unanimous, by the fans. In making comparisons with other receivers, including models of the same JRC, there were two schools of thought related mainly to the quality of listening in the CW / SSB scenarios (editor's note: utility stations, amateur radio stations) and AM / AM-S (editor's note: broadcasting stations). In any case, the NRD-545 takes advantage of a quality construction in terms of electrical and mechanical, with the typical modular construction of the JRC, and for this reason it is still appreciated today.

Valuation :

Dynamic range
Spurious response
Signal functions
Control functions
User friendly

Stars: 1=insufficient, 2=just sufficient, 3=mediocre, 4=good, 5=excellent

Review :

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