I first got my hands on the Japan Radio Company NRD-535 when I bought a used “D” model twenty-years ago.

The front panel of this receiver is a complete joy to work with. I must admit this even though my focus is largely on remote control. The big, bold tuning knob really stands out. All of the knobs and control are firm and have stood the test of time.

Back in the 1990’s this rig was viewed as the best tablet-top radio for SWL use, based on reviews at the time. Unlike some other radios, NRD-535 offered exalted carrier single sideband (ECSS) for AM detection rather than synchronous AM. And the “D” model included something really different: variable bandwidth, which was especially useful for ham radio and utility DX.

JRC made this radio between 1991-1997. See here for the brochure and the manual, as well as a video demonstration on You Tube.

Remote Control of Japan Radio Company NRD-535

The remote control protocol of this rig uses ASCII text commands and responses. For it’s time, the command set is quite comprehensive. Controls available include attenuation, bandwidth, passband shift, AGC, and noise blanker, as well as frequency and mode. Among lesser used controls, BFO pitch and clock are also available. Unfortunately, volume and tone are purely analog.

With a bit of fancy coding, it was possible to provide ERGO with a complete variable bandwidth feature with the D model. Another nice feature you can implement with the Japan Radio Company NRD-535 remote control is to tune the receiver manually and have ERGO just follow along.

The companion NVA-319 speaker is very good. It contains some analog audio filtering. I use it as my main speaker for SSB communications. On the back panel, a Line Out jack makes it easy to feed audio to the computer. RS232 connection requires a null-modem adapter.