The JRC NRD-525 Page

by Josh Rovero, KK1D

Updated: December 6, 2008

References:

1. Instruction Manual for Model NRD-525 General Coverage Receiver, JRC, 1986
2. NRD-525 General Coverage Receiver Service Manual, JRC, 1990
3. RDI Evaluates the Japan Radio NRD-525U/525E/525J Receiver, IBS, Ltd. 1987
4. "Shortwave Receivers Past & Present", 3rd Edition, by Fred Osterman

JRC NRD-525 photo from www.dxing.com

The JRC-525 is a double conversion superhet with a basic frequency coverage of 90 kHz to 34 MHz. With accessory converter CMK-165 it can also cover 34-60 MHz, 114-174 MHz, and 423-456 MHz. The radio uses surface-mount components and plug-in cards. With the accessory serial interface CMH-532, many radio functions can be controlled by computer.

The 525 is a solid performer on all modes.   A number of third party companies, such as Kiwa and Sherwood, offer accessories and modification kits.     More information can be found on the qth.net JRC mail list archive.

The CMH-532 RS-232 interface (and the more recent third party CBO-232 board) allow basic control of the radio via a serial interface.   The radio can be commanded from the computer, with the ability to set the frequency, mode, IF filter, AGC, attenuator and memories.   The radio can also be set to allow manual control, but to transmit/log the same parameters over the serial link.

DD4GB's remote control software for the NRD-525.

Thomas Nilsson has reported the following 525 mods:

• static arrestor diodes removed, replaced with 10 mH choke and a neon bulb.
• modified AVC. R105 shorted out.
• use Eskab AVC board, with addition mods.
• cascade IF filters.
  • FL1 changed to Eskab 8 pole xtal (10-12 kHz @ 6 dB)
  • FL2 changed to CFX455I (4.5 kHz @ 6 dB)
  • FL3 is CFK455I (4.5 kHz @ 6 dB)
  • FL4 is YTK 2.4 xtal filter
  • FL5 is YTK 1.8 xtal filter
  • FL6 is YTK 1.0 xtal filter
• use Eskab PLAM board with additional filters

Christophe B has lots of photos plus some links to a new RS-232 card and new CPU ROM chips for the NRD-525 at his NRD-525 Page.   Much of the content is in french, but there are many english articles as well.