Equipment / Base transceiver · Japan Radio Company (JRC)
discontinued

Japan Radio Company NRD-545

$$$$·

RX: 0.1–30 MHz
Bands
1998
Introduced
FrequencyRX: 0.1–30 MHz
BandsVLF, LF, MF, HF, VHF/UHF (optional to 2 GHz)
PowerRECEIVE ONLY. DSP communications receiver.
ModesUSB, LSB, CW, RTTY, AM, FM
Weight7.5 kg (16.5 lb) - 7.5 kg (16.5 lb) per JRC. Dimensions: 330×143×327 mm.
ConnectorSO-239 (50Ω low) + spring terminals (600Ω high)
Year1998
Connectors
antennaSO-239 (50 ohm, Low)
ext spkrexternal speaker
rs232RS-232C (computer control)
ac inAC mains (selectable voltage)
dc in12-16 VDC
antenna 600spring terminals (600 ohm, High)
power reqAC mains (selectable voltage) or 12-16 VDC.
a landmark DSP communications receiver, 990 continuously variable digital IF bandwidths RECEIVE ONLY. No transmit 40-bit DSP engine processing 13 circuit functions digitally (replaced all analog IF processing!) continuously variable digital IF filter: 10 Hz to 9.9 kHz in 10 Hz steps, 990 bandwidths! IIR (Infinite Impulse Response) concurrent Chebyshev-type digital filter (steep, excellent rejection) NO mechanical or crystal filters needed; DSP does it all 18-bit sigma-delta ADC digitizes final IF for DSP processing (hybrid analog+digital architecture) triple-conversion analog frontend: preserves analog front-end performance + DSP IF processing ECSS (Exalted Carrier Selectable Sideband) synchronous AM via DSP DSP pass-band shift DSP noise reduction: 256 steps of adjustment DSP beat canceller: 256 steps DSP auto-tracking notch filter DSP AGC: continuously variable 0.04 to 5.0 seconds in SSB/CW/RTTY built-in RTTY demodulator noise floor: -139 dBm 1000 memory channels (store: frequency, mode, bandwidth, ATT, AGC, step) large color LCD display optional NRD-545G VHF/UHF plug-in module: extends coverage to 100 kHz - 2000 MHz directly! optional CGD-197 TCXO (±0.5 ppm) RS-232C computer control clock/timer dual noise blankers adjustable tuning torque built-in speaker universal AC mains + 12-16 VDC operation NRD-535/535D successor, JRC's final amateur receiver (JRC exited consumer market)
Strengths

990 continuously variable IF bandwidths (10 Hz steps), with DSP ECSS, noise reduction, a beat canceller, a notch, and AGC all adjustable, and no mechanical filters needed. It has a -139 dBm noise floor, 1000 memories, a color LCD, an optional module that extends to 2 GHz, RS-232C, and an RTTY demodulator. It offers the most flexible IF filtering in any receiver of its era.

Weaknesses

Receive only. JRC exited the consumer market (no support). The DSP audio can sound 'digital' to some listeners (some prefer the NRD-535D's analog sound). Dynamic range is limited by the DSP processing (weaker than pure analog receivers in strong-signal environments). No spectrum scope. The NRD-545G module is rare and expensive.

Verdict

A milestone DSP receiver. The NRD-545 showed that DSP could replace mechanical IF filters: 990 continuously variable bandwidths in 10 Hz steps, each with excellent rejection, so no more buying optional filters. The 256-step NR and beat canceller dig signals out of noise. As JRC's final consumer receiver before it left the amateur market, it is a milestone product, and the optional VHF/UHF module to 2 GHz is rare and valuable.

The JRC NRD-545 was Japan Radio Company's last and most advanced consumer HF receiver, a receive-only set that bridged the analog and digital eras. It covers 100 kHz to 30 MHz in all modes, using a hybrid design: a triple-conversion analog front end feeds an 18-bit sigma-delta analog-to-digital converter, after which a digital signal processor handles demodulation, filtering, digital noise reduction, and passband shifting.

That DSP architecture gave the NRD-545 enormous flexibility (continuously variable bandwidth, a wide range of filter shapes, and noise-reduction tools that analog receivers could not match) wrapped in the same solid JRC build quality as its predecessors. It became a sought-after receiver for demanding listeners, and because it was produced only until 2008 in modest numbers, clean units command strong prices on the used market.

It is a discontinued classic. See its analog predecessor the NRD-535 and the Drake R8.