Manufactured by Japan Radio Co., Tokyo.
Known as a manufacturer of commercial receivers, especially in maritime communications, the NRD-505 was Japan Radio Corp.s first receiver in a price range adapted to the amateur radio market launched in 1977. The NRD-505 soon had many enthousiasts due to its excellent receiver concept and the superior performance.
- Principle: Double conversion, IF 70.455 MHz, 455 kHz
- frequency range: 100 kHz - 30 MHz
- Frequency display digital display, 100 Hz
- Frequency memory: 4 memories (optional)
- Signal processing: RF gain, AGC x 2, noise blanker
- Sensitivity: SSB <0.5 μV / Selectivity: 4.4 kHz / 2.0 kHz (-6 dB)
- Mains operation: 110, 220 V
- 340 x 158 x 352 mm, weight 10 kg
According to its semi-professional origins, the NRD-505, with its 340 x 158 x 352 mm metal cabinet and a weight of about 10 kg, has a very different external appearance from sets such as the Grundig Satellit 3400 or the Sony CRF-320, which were developed with the home electronics market in view.
The NRD-505 is a station receiver intended for mains operation and must be connected to an external aerial. On the back there is a PL / SO-239 aerial connector, cinch sockets for loudspeaker, line out but also an IF output and a multi-pin connector to operate the receiver in conjunction with a transmitter.
In view of the complexity of the receiver, the front panel is very structured, this is typical for JRC. The S-meter is of course designed as an analogue instrument and is calibrated in S-steps. The red coloured LED frequency display in the middle of the upper front panel section indicates the operation frequency with an accuracy of 100 Hz, but a frequency offset with the Fine tuning / DeltaF control activated is not indicated. Below the LED display, which is somewhat difficult to read with strong backlight, is the red backlit analogue main tuning dial, and below it the main tuning knob. When operated in the semi-dark shack, the dial is a delight to the eye and reading it is not very tiring.
In the lower left part of the front panel, next to the headphones and REC OUT jacks, are the band switch for the 30 1 MHz ranges and the controls for RF gain (RF GAIN) and volume (AF GAIN).
At the top right of the front panel are the pushbuttons for the four (!) frequency memories, which were available as an expensive option at the time. The frequency (without operation mode and IF filter setting, remeber, the set has an analogue design) is retained in the memory only for a few hours. Below the row of typical JRC switches for receiver fine tuning „DeltaF“, noise blanker and attenuator are the rotary controls for fine tuning, the BFO beat frequency and to the right the selector for the diffferent operation modes and the AGC switch. As is typical for professional units, the RF gain of course can be controlled completely manually in the AGF OFF position.
On the one hand, Japan Radio's NRD-505 is still a seriously sensitive and selective shortwave receiver, on the other hand with its frontpanel design and straightforward operating concept an absolute classic. Of course, there are trade-offs to be made in terms of all the goodies of modern microprocessor-controlled sets with a multitude of memories and electronic signal processing with a corresponding selection of steep-edged DSP filters.
In my collection, I consider the NRD-505 as a precious jewel, its design can only be compared to that of the NRD-515 - and the greatest joy comes when you operate the set on the bands.
Double conversion superhet.
The set is solid state.