KA0 AMRS: Auxiliary Military Radio Stations
[/J]  [J2-7]  [J8]  [J9]  [JA]  [KA2]  [KA3]  [KA4]  [KA5]  [KA6]  [KA7]  [KA8]  [KA9]  [KA0]  [KA1]  [KG6I]  [KR6]  [KA b4 DU]  (callsign.jp)
Please inform me of any additional data, thank you. — Ryota "Roy" Motobayashi, JJ1WTL@JARL.COM
While KA0 is not reserved for AMRS nowadays — yes, KA2-KA9 2×2 call signs are only reserved — it was actually used in Iwojima I., in Ogasawara in our past.
ex-Call Call Licensee Address es-Call Source
KA0 — Iwo Jima I. (now JD1) 1950s
  KA0CY   Everett E. Worrell, Jr. Iwo Jima I. KA3CY
W4WJJ		 1956f-w-57sp-su-f;
Himself (1956-57)
  KA0IJ   Robert L. Green 1956th AACS Squadron, APO 815   1952w-53sp-su-f-w; AD1C (1953-); QSO Dec. 26, 1958
    Clayton Dalton Airways & Air Communications Service, Det. 1956-2, 1956th AACS Squadron, APO 815   1954sp-su-f-w-55sp-su-f-w-56sp-su-f-w-57sp-su
    (Club?) APO ??? c/o PM, San Francisco, Calif.   "Hello World" (QSL dated July 1, 1955)
  KA0IK   Gene U.S. Air Force "Emergency and Refueling," APO 815, San Francisco, California   KA0IK QSL card by W5KNE
  KA0SC T.Sgt Scott H. Chase 1964 AACS Squadron, APO 815 (Iwo Jima I.) W9OP K8CS Ham Gallery (QSO 1957); W8HVG qrz.com; W5KNE

References

[/J]  [J2-7]  [J8]  [J9]  [JA]  [KA2]  [KA3]  [KA4]  [KA5]  [KA6]  [KA7]  [KA8]  [KA9]  [KA0]  [KA1]  [KG6I]  [KR6]  [KA b4 DU]  (callsign.jp)
Oct. 4, 2020, Ryota "Roy" Motobayashi, JJ1WTL