Craig - here is a wartime description of the airfield that might be of some interest:
Königgrätz (CZECH) (a.k.a. Hradec Králové) (50 14 50 N – 15 51 00 E) (AFHRA)
General: operational airfield (Einsatzhafen) in Czechoslovakia 102 km ENE of Prague, 23 km NNE of Pardubice and 4.5 km NNE of Hradec Králové. The N/S flowing Elbe (Labe) River was just 1.6 km W of the airfield.
History: Hradec Králové was used by the Czech Air Force as a training school for all types of aircraft up to and including light bombers. The Luftwaffe turned it into a large signals training center after taking it over in 1939 and it continued in this capacity right up to the end of the war.
Dimensions: approx. 915 x 915 meters (1000 x 1000 yards).
Surface and Runways: grass surface that softened in wet weather. Had a short, approx. 320 meter (350 yard) E/W prepared strip in the center of the landing area in Jun 44. The composition of the strip – concrete, asphalt, steel matting, wood planking, reinforced turf, etc. – has not been determined.
Fuel and Ammunition: there were refueling points in front of the hangars and underground bulk storage on the W boundary between the hangars.
Infrastructure: had 1 very large hangar and 4 large hangars in a row that curved along the SW corner of the field, all of these fronted with a continuous paved hangar apron, plus 1 medium hangar on the N boundary near the NE corner and a second building of the same size off the center of the W boundary for a total of 6 or 7 hangars. Additional workshops were located behind the SW hangars. The station compass swing base was off the W boundary. A large barrack complex sat off the SW corner behind the hangars. Nearest rail connection was in Hradec Králové.
Dispersal: no organized dispersal as of Jun 44. Aircraft usually parked around the hangars and along the S boundary.
Defenses: unknown - probably few if any before fall 1944.
Remarks: left largely untouched by Allied bombing attacks, probably because of its low target priority in that it was used mainly as a signals training facility until late 1944.
Mar 45: He 111s from KG 4 began airlifting supplies from Königgrätz to Breslau, which was surrounded.
Operational Units – not complete): III./KG 77 (May-Oct 39); II./KG 30 (Nov 44 – Jan 45); II./SG 4 (Mar-May 45); Stab, I., III./KG 4 (Mar-May 45); 12./Verb.Geschwader 2 (Apr-May 45); 14.(Eis.)/KG 55 (Apr 45); parts of Schleppgruppe 1 (Apr-May 45).
School Units: Luftnachrichtenschule 2 (1940 – Apr 45); Stab, I., II., III./Ln.-Ausbildungs-Rgt. 301 (Aug-Sep 44); Ln.-Ausbildings-Rgt. 302 (Sep 44)?; parts of II., III./Ln.-Ausbildungs-Rgt. 303 (Aug-Sep 44); I., III./Ln.-Ausbildungs-Rgt. 305 (Aug-Sep 44).
Reserve Training & Replacement Units: 9./Erg.JG 1 (Feb – Apr 45).
Station Commands: Fl.H. Königsgrätz (1939 – Jan 43); Fl.Pl.Kdo. A 22/XVII (Jan 43 – Mar 44); Fl.H.Kdtr. A(o) 15/XVII (Apr 44 – Apr 45).
Kommandant (prior to the establishment of a numbered station command): Obstlt. Kurt Schlabach (c.Aug 39 - 20 Aug 40); Oberst Aldo Saul (20 Aug 40 - 31 Oct 41).
Lw. Garrison and Station Units (on the airfield, in the city or nearby on various dates – not complete): Stab/I. Flakkorps (May 45); 7. Flugh.Betr.Kp./KG 77 (May-Oct 39); 8. Flugh.Betr.Kp./KG 77 (May-Oct 39); 17.(Funkh.Ausb.)/Ln.-Rgt. 1 (Sep 44); Stab II.(Feldfernkabel-Bau)/Ln.-Rgt. 38 (May 41); Stab and IV./Ln.-Ausb.Rgt. 4 (Sep 44 - 1945); 4.(Funkh.)/Ln.-Abt. 356 (Jan-Apr 45); elements of Ln.-Telegrafenbau-Abt. z.b.V. 11 (Oct 44); Lw.-Bau-Btl. 131/XVII (K) (Mar 45).
[Sources: AFHRA A5258 pp.1121-22 (18 Jul 44); chronologies; BA-MA; NARA; PRO/NA; web site ww2.dk]
There were just 3 Luftwaffe officers in the rank of Hauptmann or above by the name of GRAUBNER. Here is the one I think you are referring to, although it does not say that he was Horstkommandant of Königgrätz even though he may have been the de facto base commander by virtue of him being the Kommodore of KG 4:
GRAUBNER, Reinhard. (DOB: 02.08.15 in Frankfurt/M.). (R, DKG). 1934 joined the Reichswehr as a Pionier. 1935 trf to the Luftwaffe, and later assigned to Fl.Gr. Gotha (I./KG 253). (n.d.) trained as an observer with Grosse KFS Tutow. 05.39 in KG 4. 01.09.39 Oblt., appt Adj. Stab/KG 4 (to 21.09.39). 1940 with 6./KG 4. 05.41 briefly served in Iraq. 01.12.41 Oblt., appt Staka 4./KG 4 (to 01.10.42). 16.02.42 awarded the Ehrenpokal. Spring 1942 promo to Hptm. 05.06.42 Hptm., awarded DKG, II./KG 4. 01.11.42 Hptm., appt Adj./KG 4 (to 29.01.43). 01.02.43 Hptm., appt provisional Kdr. II./KG 4 (to 30.06.44). 03.09.43 Hptm., awarded Ritterkreuz, Kdr. II./KG 4. 01.01.44 promo to Maj. 07.44 Maj., appt Kdr. III./KG 4 (to c. 23.12.44). 04.12.44 or 30.12.44 Maj., appt Kommodore KG 4 (to 08.05.45). 09.05.45 captured by the Americans. Credited with at least 420 combat missions during the war. †03.11.86 in Walluf near Eltville.