harris-l.gif (1297 バイト) Harris R-2368/URR (RF-590A) Receiver

                    Front Panel Display of Harris R-2368/URR receiver


         This receiver is a military version of RF-590A.
        R-2368/URR (AN/URR-79(V)1) is used in US Navy and US Coast Guard.
        Serial Number: A1417
        The price was said to be $16,000.
        Differences to RF-590A
           No external SP output
           No mute wiring
           Output connector: dSub connector only. (No TB connector)
           Limited to 4 Xtal Filters
           Option: ISB, Preselector
        Options are inclusive RF-553-01 Remote Control Adapter, RF-592 Remote RS-232C Control (A25),
        RF-595-01 Standard ISB (A18), RF-596A-02 Digitally Tuned Bandpass Filter (A19) .
        But not RF-597A NB (A20) and full of filters..

        Finally, I have acquired a Noise Blanker!  Parts No.10073-6810 in Jan. 2008.


rf-590_1.jpg (54817 バイト)
Upside view of R-2368.
Mounted ISB board.
Removed both A19 Preselector
 and Shield Cases.
Original filters configurations,
4 Xtal filters:  0.3kHz, 6kHz
and 2.55kHz USB/LSB.

This receiver employs
upconversion system,
1st IF 40.455MHz and
2nd IF 455kHz.
Frequency ranges are from
14kHz to 30MHz.
Modes are USB/LSB/ISB, FM, CW,
AM and memory channel are 100CH.
Microprocessor is 8058A and its clock
is 6MHz. The firmware is 208H.

       Robust input filter configuration Preselector and LPF.
          2-29.99MHz is BPF.
        Autotune capability to receiving frequency, 20dB attenuation @+-10%.
        BPF are in 4bands, 2-3.91, 3.92-7.59, 7.6-15.04, 15-30MHz.
        Insertion loss is @max 6dB and have no compensation amplifier.
        presele.jpg (29582 バイト)     
        Digital Preselector (Upside view, 2 to 30MHz BPF)   Digital Preselector (Downside view, LPF and protect)

           Input filter (30MHz LPF)

          1st_if.jpg (31522 バイト)    1st Conv. (DBM, subsequent roofing filter is 6.4kHz BW)
                                                                       Measured actually almost 12kHz BW.
          2nd_if.jpg (31464 バイト)   2nd mixer, using SBL-1 DBM and 2 Xtals are used for image suppression.

            Additional filters mounted: 1.2k, 3.3k, 10k BW
                                                      Original filters are 0.3k, 6k, 2.7k x 2(for LSB, USB)
             Synthesizer, 1 board.(Stream lined)

Difference: RF-590A vs RF-590 Pictures of RF-590s are from e-bay.
        Upside view of RF-590A(left), RF-590(right): No ISB and preselector

          rf-590_6.jpg (37308 バイト)    
        Downside view of RF-590A (left), RF-590 (right): PLL are separate 5 units

          if.jpg (30836 バイト)    
        IF BPF view: RF-590A are using all  XFs.        IF BPF view: RF-590 are using all Mechanical Filters.
                                          Mechanical Filters of RF-590: 3.2kHz USB/LSB, 0.3 CW, 1.0 CW, 3.2 AM, 6 AM


rf-590_3.jpg (21873 バイト)Right-hand keypads and their displays.
Receiving frequency and memory CH (00 to 99).
Small buttons are left to right: NB, TUNE RATE, FREQUENCY, CHANNEL

Left-hand keypads and their displays.
 Display: AGC, mode, BW, dwell, BFO
 Small buttons are left to right: AGC/MODE/BW/DWELL/GROUP/BFO
 Large buttons are left to right: SPKR, TEST, RECALL, LOAD, PROG, SCAN, RCV(White).

Meter display and it's meter SW
AF output: -10dBm to +15dBm.
RF input:  0 to 100mV.
Notation: 1uV, 10uV, 100uV, 1mV, 10mV, 100mV.

Front Panel description
        RF, AF GAIN, COR/SQUELCH VR  COR: carrier operated relay
        MODE        AM / CW / USB / LSB / FM / 2-ISB
        BW            6 Filters (AM / CW / FM)
                        USB, LSB 2.7kHz BW.
                        AM 3.2/ 6/ 10/ 16kHz. CW 0.3/ 1.0kHz.
        AGC time constant   DAT/ FST/ MED/ SLO  30mS/200mS/2.5S
        AGC          ON/OFF
        DWELL       0.1 -10 sec
        GROUP       00-09
        BFO          (CW MODE) +-9.9kHz
        SPKR         SP on/off lock
        TEST         for BITE
        RECALL      Call AUX CH
        LOAD         Write Memory
        PROG         Program scan group select
        SCAN         0-99CH
        RCV           White button, Normal position.
        Meter        AF / RF : RF / AF (ISB-LSB) ISB
                        Variable in ISB for selecting USB/LSB audio

    Harris RF-590A(R-2368/URR)  LF/MF/HF-SSB Synthesized Receiver Specifications from technical manual.
                                                                                                                                                   (  ) Latest specifications

Frequency Range

 14 kHz to 30.000 MHz                                                                                                  (10 kHz to 30 MHz)


 1 Hz -- tuning steps 1/10/100 Hz/1/10/100 kHz/1 MHz


 8 digit Green Fluorescent Display readout FREQ/BFO +- 9.9 kHz to 10 Hz CHANNEL Mode/AGC/BW/DWELL RF/AF meter

Conversion Type

 Dual Conversion -- 40.455MHz 1st IF -- 455 kHz 2nd IF


 +-0.5 parts in 10 to 7th (OCXO) 1MHz for Navy, external outlock 1 MHz, 5 MHz, 10 MHz


 (2) ISB -- USB -- LSB -- AM -- CW -- FM


 Off/Data/Fast/Medium/Slow -- 20mS/35mS/200mS/2500mS


 0.2uV/-121dBm in 0.3 kHz CW, 0.6uV/-111dBm in 2.7 kHz SSB, 2.5uV/-99dBm in 6 kHz AM, for 10 dB s/n ratio                                                                                                      (0.15uV/CW, 0.35uV/SSB, 1.5uV/AM)


 Xtal Filters - LSB/USB - 2.7 kHz - AM - 3.2kHz - 6.0 kHz - 10kHz - 16 kHz  - CW - .3 kHz - 1kHz -FM - 16 kHz @-3dB


 max input 25W , 30V out-of-band, 5V in-band cut incircuit and fault lamp indicate                             (100W)

Remote Control

 RS-232C/RS-422/M IL-188C -- 25 pin D-Sub rear plug -- Built in Self Test


 100-260 volts AC, 48 to 1000 Hz or 10-40 volts DC -- 90 watts                                                       (75watts)


 Original Price $9700-17000 -- 1982-


 19"(48.3cm) wide -- 5.25"(13.33cm) high -- 20.5"(52cm) deep -- 40 lbs.(18.5kg)

    in-band:        -40dB or better for (2) 50mV sigs within the IF passband.                                                      (-50dB, -7dBm)
    out-of-band: -90dB or better for (2) -20dBm signals separated 100 kHz or more.                                (-50dB, 0dBm, 30kHz)
    Cross Modulation:10% or better for a 900mV 30% modulated interfering signal removed
                                100 kHz or greater from the desired signal of 30uV.
    Reciprocal Mixing:The apparent noise appearing at the Receiver input when in a 3 kHz bandwidth,
                                caused by a -17dBm signal 100 kHz off tune, is less than 0.3uV.
                                                                                                                                           (<=-107dBc, 3kHz, 100kHz)
    TOIP: +27dBm

 The author conducted sensitivity testing of my receivers. December 2008
          Mode: CW: BW=0.3kHz/AGC off/F=29.9MHz/BFO +650Hz/s+n/n 10dB used HP 8948A SSG and Shibasoku 796E..
                    RA3701 -122.7dBm/-131.4dBm (RF amp off/on)
                    RA6790/GM -116.4dBm, RA6793A -118.3dBm
                    RF-590A -122.2dBm

Overall AF characteristics by  filters







AM 80%









    RF input: 28MHz. AF line output: -6dB point/ 1kHz reference(Hz)
    SSB filters were actually measured : 3.2kHz BW@-3dB.

455kHz IF Filters characteristics center frequency:455kHz(tnx JA2LZV)
      2.55kHz USB span: 10kHz 3.2kHz/-3dB                   6kHz AM span: 20kHz 8.6kHz/-3dB

      16kHz AM span: 100kHz 35kHz/-3dB                          1kHz CW span: 10kHz 1.2kHz/-3dB

Modification done
          1. Addition of muting function.
          2. Wired for external speaker.
          3. Bypassing built-in digital preselector using front panel NB SW.
             After I got NB unit, I have 2 kind preselector units bypassing and original.
          4. AGC slow timeconstant from 2.7sec to 1.4sec for smoothing.
          5. Change memory battery, NiMH 70mAH. Replace R2 to 15kohm.
Memory battery of Harris RF-1310A (tnx JA2AEV)
Heavy corrosion from Ni-Cd Battery occurred
as well as my  R-2368 radio experienced.

          6. BITE error
                800kHz ref Q18 2N2709 is NG. Change to 2SA683.

Got Junk modules in Jan., 2008
          I have got the R-2368 receiver's modules from Yahoo auction.
          Following modules:
          A1, A2, A3, A4, A5, A10, A11, A12, A13, A14, A15, A16, A18, A19, A20, A21, A25
          No front panel modules acquired, but the control module.
          Succeeded in repairing all modules for perfect performance.
          Bare diecast chassis

Noise Blanker
        Discovered a  'A20 NOISE BLANKER' shield case in various module.
        Then detected a noise blanker module!
        I challenge to make it NB functional, though no circuit diagram available.
        RF: 1st Conv output to J3 of NB.
        2nd Conv input to J1 of NB.
        Connect J4 to J2 of NB.
        Connect A19 Preselector J9/5p to NB/ 6p.
        Push only NB button, NB lamp on and ignition noise will disappear.
      Circuit of NB
        40.455MHz in-pre amp-Mix-3 x 9.1MHz amp-detector-blanking MM 0.3mS
                                            |                                             |
                                 31.355MHz OSC                               gate
        A20 NOISE BLANKER Shield case               A NB module. Parts No.10073-6810. VR is for setting threshold of NB.

        Connection of NB module                   Wave Form of NB  Up: Noise Detected.  Down: Cramped wave

        A2 1st Conv
          Rev.C, Roofing filter is 6.4kHz BW

          A3 2nd Conv is differentiate in two modules
          Previous module: Rev.C using 2 notch Xtals           Junk module: Rev.G using 20kHz BW Xtal filter

        A5 IF/AF module
          Broken at right upside and few parts missing.
          AF/IF module(Before)                                               Broken at right up side corner.
          Close up view of repaired parts(After)                                             Backside of module

          -8V regulator is changed LM337 to 79L05. Changed resistors: R5 and R7.

SMB connector broken.
See inside, you can see residue of SMB connector inner shield.

        A14 Control. This module was tougher in repairing for me.
        Before repairing.
        Rinsing the module thoroughly to washing out alkali battery liquid.

        All lit up '8' when switched on for the first time.

          Changed with new CPU/8054A. (tnx JA2TY)
          Found several defects of print patterns by using a circuit tester. Repaired 5points.
          Resoldered all through-holes.
      Wow!! Working.
                  The Firmware is 208L
        Left: Print circuit before repairing, dirty looking due to alkali battery liquid.
        Right: Changed CPU/8054A and J15 removed. Jumpered between lost circuit by red wires.
        Replaced a super capacitor for memory back up.
        Executed 'detail A' repair. Capacitor is 0.1F.

        Does anyone succeeded in remote controlling between RF-590A and RF-1310A by computer?

          HARRIS HP
          Latest specification of RF-590A form the Harris home page. pdf file
          RF-590 Instruction manual from premium-rx org

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