These are very interesting tables compiled and copyrighted by Les Locklear. Please, e-mail any correction or addition.
| JX Model | Date added (according to Hammarlund files) |
Comments |
| 1-9 | 9-19-51 | |
| 10,11 | 11-8-51 | |
| 12 | 11-9-51 | |
| 13 | 11-26-51 | |
| 14 | 3-12-52 | |
| 14 | 4-23-52 | Name plate to add R-274A/FRR |
| 14 | 9-29-52 | 'A' was R-542/FRR |
| 15-17 | 6-17-52 | |
| 18 | 6-26-52 | |
| 19,20 | 8-27-52 | |
| 21-26 | 2-13-53 | |
| 24 | 10-9-57 | Special supplied to NAVSHIPS 91661, R-274B/FRR |
| 27 | 3-13-53 | |
| 28 | 10-5-53 | |
| 28 | 3-8-54 | Name plate added |
| 29 | 3-12-54 | |
| 30-33 | 12-28-54 | |
| 34,35 | 7-7-56 | |
| 36 | 10-3-57 | |
| 37,38 | 3-28-61 | |
| 39 | 7-21-61 | Made for FAA contract FA-2338 same as 21, except has 6 position freq control instead of 7 |
| Model | Designation | Comments |
| 1 | JX-1 | |
| 2 | JLX-2 | |
| 3 | J-3 | |
| 4 | J-4 | R-320A/FRR SIGNAL CORPS 19474-PHILA-50-06 |
| 5 | J-5 | R-483/FRR SIGNAL CORPS 21478-PHILA-50 |
| 6 | JX-6 | R-274B/FRR NAVY NOBSR-52039 |
| 7 | JX-7 | |
| 8 | JX-8 | |
| 9 | JL-9 | |
| 10 | JX-10 | |
| 11 | J-11 | MADE TO COMPLETE NAVY ORDER ECN-1156 |
| 12 | JX-12 | R-274A/FRR SIGNAL CORPS 3376-PHILA-52 |
| 13 | J-13 | SAME AS 5, NAME PLATE CONTRACT 16838-PHILA-51, SERIAL NUMBERED 52 TO 67 INCLUSIVE |
| 14 | JX-14 | R-274C/FRR SIGNAL CORPS 1689-PHILA-51-01 |
| 15 | JLX-15 | |
| 16 | JL-16 | |
| 17 | JX-17 | AIR MATERIAL COMMAND |
| 18 | JX-18 | |
| 19 | J-19 | |
| 20 | J-20 | R-483A/FRR SIGNAL CORPS 3479-PHILA-52-06 |
| 21 | JX-21 | |
| 22 | J-22 | |
| 23 | JLX-23 | |
| 24 | JL-24 | |
| 25 | J-25 | |
| 26 | JX-26 | R-274C/FRR 3376-PHILA-52 |
| 27 | JLX-27 | |
| 28 | JX-28 | R-620/FRR SIGNAL CORPS 25693-PH-53-61 on contract DA-36-039-SC-49453 |
| 29 | JX-29 | MADE FOR CONTRACT XG-1178 |
| 30 | JX-30 | DIVERSITY |
| 31 | VLF-31 | |
| 32 | JX-32 | BLACK WRINKLE FINISH ON FRONT PANEL, FIRST MADE FOR MACKAY RADIO THEIR ORDER # M-41666 |
| 33 | JLX-33 | SAME AS 17, EXCEPT FREQ: .1 TO .4 and 1.35 TO 29.7 |
| 34 | JL-34 | FIRST MADE FOR CIA ORDER XG-1765, FREQ: .1 TO .2 and .54 TO 14.8 |
| 35 | JX-35 | R-274B/FRR ORDER NOBSR-71369, USES 0-10 KC BFO |
| 36 | ||
| 37 | JX-37 | |
| 38 | VLF-38 | SAME AS VLF-31 EXCEPT 25 CYCLE |
| 39 | JX-39 | FAA CONTRACT FA-2338 |