THE
HAMMARLUND HISTORIAN
SP-600
DESIGNATIONS
PRODUCTION DATE | SUFFIX # | NOTES |
Sept. 1951 | SP-600-JX-1 | Std. Frequency range 540 khz-54 MHz. Also designated R-274A/FRR ("Fixed Radio Receiver") Signal Corps order no. 1689-Phila- 51-01. Note: many early SP-600's were simply designated SP-600-JX |
Sept. 1951 | SP-600-JLX-2 | Frequency range 100-400 khz, 1.35-29.7 MHz |
Sept. 1951 | SP-600-J-3 | Std. Frequency range, 540 khz-54 MHz. No X-tal frequency control. |
Sept. 1951 | SP-600-J-4 | Std. frequency range, 54O khz-54mhz. No X-tal frequency control. Equipped with 25 to 60 cycle ( hertz ) power supply. Signal Corps. R-320A/FRC, order no. 21478-Phila-50-06. Also has separate IF gain control located where the X-tal frequency control was normally located. Part of OA-58B/FRC Set. |
Sept. 1951 | SP-600-JX-6 | Std. Frequency range, 540 khz-54 MHz. BFO range 0-10khz. U.S. Navy model R-274B/FRR, order no. Nobsr-52039 19 October, 1954. Navships manual 91661. |
Sept. 1951 | SP-600-JX-7 | Std. frequency range, 54O khz-54mhz. |
Sept.1951 | SP-600-JX-8 | Std. frequency range, 54O khz-54 mhz. Manufactured for Welch contract no. XG-479. Believed to be a cover for a CIA contract. |
Sept. 1951 | SP-600-JL-9 | Frequency range, 100-400khz, 1.35-29.7 mhz. No X-tal frequency control. |
Nov. 1951 | SP-600-JX-10 | Std. frequency range, 54O khz-54 mhz. Replaces JX-7. |
Nov. 1951 | SP-600-J-11 | Std. frequency range, 54O khz-54mhz. No X-tal frequency control.Note: This model made to complete NAVY order, without the changes per ECN1156 as standard J series. Replaces J-3. |
Nov. 9, 1951 | SP-600-JX-12 | Std. frequency range, 540 khz-54mhz. Signal Corps. R274A/FRR, order no. 3376-Phila-52. Replaces JX-1. |
Nov. 26, 1951 | SP-600-J-13 | Std. frequency range, 54O khz-54mhz. No X-tal frequency control. Signal Corps. order no. 16838-Phila-51. Serial no's. 52 to 67 inclusive. 25 to 60 cycle power supply. Replaces J-5. 16 receivers produced on this order. |
April 23, 1952 | SP-600-JX-14 | Std. frequency range, 54O khz-54mhz. Signal Corps. R274C/FRR, order no. 3376-Phila-52. Also designated previously as R-542/FRR. Replaces JX-10. |
June 17, 1952 | SP-600-JLX-15 | Frequency range, 100-400 khz, 1.35-29.7 mhz. Replaces JLX-2. |
June 17, 1952 | SP-600-JL-16 | Frequency range, 100-400 khz, 1.35-29.7 mhz. No X-tal frequency control. Replaces JL-9. |
June 17, 1952 | SP-600-JX-17 | Std. frequency range, 54O khz-54mhz. Diversity receiver. Manufactured for Air Material Command. Note: easily identified by 'red metal knobs'. The most common of the SP-600 series receivers. |
June 26, 1952 | SP-600 JX-18 | Std. frequency range, 54O khz-54mhz. Made for ' GAUVREAU ' contract. Replaces JX-10. |
Aug. 27, 1952 | SP-600-J-19 | Std. frequency range, 54Okhz-54 MHz. No X-tal frequency control. Equipped with 25 to 60 cycle power supply. Replaces J-5, J-13. |
Aug. 1952 | SP-600-J-20 | Std. frequency range, 54O khz-54mhz. No X-tal frequency control. Same as J-19. Signal Corps. R-483A/FRR, order no. 3479-Phila-52-05. Equipped with 25 to 60 cycle power supply. Replaces J-19. |
Feb. 13, 1953 | SP-600-JX-21 | Std. frequency range, 54O khz-54mhz. Replaces JX-10. |
Feb.1953 | SP-600-J-22 | Std. frequency range, 540 khz-54mhz. No X-tal frequency control. Replaces J-11. |
Feb. 1953 | SP-600-JLX-23 | Frequency range, 100-400 khz, 1.35-29.7 mhz. Replaces JLX-15. |
Feb. 1953 | SP-60O-JL-24 | Frequency range, 100-400 khz, 1.35-29.7 mhz. No X-tal frequency control. Replaces JL-16. |
Feb. 1953 | SP-600-J-25 | Std. frequency range, 54O khz-54mhz. No X-tal frequency control. Equipped with 25 to 60 cycle power supply. Replaces J-19. |
Feb. 1953 | SP-600-JX-26 | Std. frequency range, 54Okhz-54mhz Signal Corps. R274C/FRR, order no. 3376-Phila-52. Effective upon Signal Corps. approval of TAR#10 dated 2-12-53. Replaces JX-14. |
March 13, 1953 | SP-600-JLX-27 | Special frequency range, 200-400 khz, 540 khz-29.7 mhz. |
Oct. 5, 1953 | SP-600-JX-28 | Std. frequency range, 54O khz-54mhz. Signal Corps. R-620/FRR, order no. 25693-Phila-53-61, contract DA-36-039-SC-49453. |
March 12; 1954 | SP-600-JX-29 | Std. frequency range, 54O khz-54mhz. Made for CIA contract no.XG-1178. |
Dec. 28, 1954 | SP-600-JX-30 | Std. frequency range, 54O khz-54mhz. Diversity receiver. Replaces JX-17 red metal knobs, not very common. |
Dec. 1954 | SP-600-VLF-31 | Special frequency range, 10-540khz X-tal frequency control (4 position). Very low frequency receiver. |
Dec. 1954 | SP-600-JX-32 | Std. frequency range, 540 khz-54mhz. Black wrinkle finish front panel with white engraved lettering. Made for Mackay Radio, their order no. M-41666, Hammarlund production order no. 2467- 300. Internally the same as JX-21. |
Dec. 1954 | SP-600-JLX-33 | Special frequency range, 100-400 khz, 1.35 - 29.7 mhz. |
Aug. 7, 1956 | SP-600-JL-34 | Special frequency range, 100-200khz, 54O khz-14.8 mhz. Made for CIA. Their order no. XG-1765. |
Aug,. 1956 | SP-600-JX-35 | Std. frequency range, 540 khz-54mhz. X-tal frequency control. BFO range 0-10 khz. U. S. Navy R-274B/FRR, order no. NObsr-71369. Navships manual 91661. |
Oct. 3, 1957 | SP-600-JX-36 | Std. frequency range, 540 khz-54mhz. X-tal frequency control. Made for FBI, their order no. FBI-16876, their contract no. J-FBI-3873. Same as JX-21, except for addition of audio input jack on rear of chassis. |
Oct. 9, 1957 | SP-600-JL-24 ( Special ) |
Frequency range, 100-400 khz, 1.35-29.7 mhz. No X-tal frequency control. U.S. Navy R-274B/FRR. Supplied to NAVSHIPS 91661, R-274B/FRR per PL-33910-1. Reason for 'Special' designation not known. |
Mar. 28, 1961 | SP-600-JX-37 | Std. frequency range, 540 khz-54mhz. X-tal frequency control. 25 to 60 cycle power supply. Otherwise, same as JX-21. |
March, 1961 | SP-600-VLF-38 | Special frequency range, 10-540 khz. X-tal frequency control (4 position). Very low frequency receiver. 25 to 60 cycle (hertz) power supply. Same as VLF-31 except for 25 to 60 cycle (hertz) power supply. |
July 21, 1961 | SP-600-JX-39 | Std. frequency range, 540 khz-54 mHz. Made for FAA contract no. FA-2338. |
June 1969-1972 | SP-600-JX-21A | Std. frequency range, 540 khz-54 mhz. This was the last series of SP-600's manufactured. It had 22 tubes vs. 20 in other models. Also, a separate product detector, LSB,USB,CW,MOD switch. Appearance was different from other SP-600's in that the knobs had no metal skirts, the front panel was engraved with markings for Xtal phasing, selectivity, bfo, audio gain, rf gain. Also is marked JX-21-A on front panel. This is probably the rarest of the SP-600 series. Click Here for SP-600-JX21A Pictures |