The following list contains the aeronautical radio beacons that were active in Yugoslavia in the mid of the 1950s. The list is likely to be incomplete, as there is no information on military radio beacons. All information is outdated and may not be used for navigational purposes.
At this time predominantly Non-Directional Beacons (NDB) were used. At Belgrade-Zemun airport, however, there was already a VOR in operation.
Explanations

Abbreviations
approx. | approximately | |
civ | civil | civil operator |
GP | Glide path | Glide path transmitter |
ILS | Instrument Landing System | (Approach and landing aid) |
IM | Inner Marker | Marker beacon just in front the runway |
kHz | Kilohertz | (Unit for frequency) |
L | Locator | Non-directional beacon for the approach |
LLZ | Localizer | Localizer transmitter |
LMM | Locator Middle Marker | Combination of Middle Marker and Locator |
LOM | Locator Outer Marker | Combination of Outer Marker and Locator |
m | Meter | (Unit for length) |
MHz | Megahertz | (Unit for frequency) |
mil | military | military operator |
MM | Middle Marker | Marker beacon |
NDB | Non-directional beacon | Non-directional beacon on long or medium waves |
NM | Nautical Miles | (Unit for length) |
OM | Outer Marker | Marker beacon |
PRMG | ПРМГ Посадочная радиомаячная группа | Soviet / russian military instrument landing system |
RSBN | РСБН Rадиотехническая система ближней навигации | Soviet / russian military radio navigation system |
SBA | Standard Beam Approach | Approach system, Lorenz system, predecessor of the ILS |
THR | Threshold | Runway threshold (most often with number of runway) |
transf. | transformed | Coordinates were converted from a different reference system, therefore there may be deviations. |
VAR | Visual-Aural Rnange | |
VOR | VHF Omnidirectional Radio Range | |
W | Watt | (Unit for power) |
WGS84 | World Geodetic System 1984 | (geospatial reference system, GPS coordinates) |
Directory
For historical information only, do not use for navigation or aviation purposes!
Belgrade: Zemun Airport (Beograd, Аеродром Београд Земун)
Belgrade-Zemun Airport was located in the former People's Republic of Serbia (Narodna Republika Srbija / Народна Република Србија). Today, the airport is closed, the area belongs the municipality "Novi Beograd" (Нови Београд).
Belgrade: NDBN4449 E02022 (approx.), 091°/1.4 NM to field
Google MapsBD, 380 kHz, 800 W
Belgrade: NDBN4448 E02024 (approx.)
Google MapsZM, 399 kHz, 100 W
Operated on request.
Belgrade: VORN4449 E02020 (approx.)
Google MapsYBD, 112.3 MHz

Belgrade Zemun Airport, Yugoslavia, 1953 (Source: DoD)
Bled/Lesce: NDBN4621 E01411 (approx.)
Google MapsLC, 390 kHz, 100 W
People's Republic of Slovenia (Ljudska republika Slovenija / Socijalistička Republika Slovenija / Социјалистичка Република Словенија)
Ivanicgrad: NDBN4542 E01629 (approx.)
Google MapsIG, 316 kHz, 500 W
Operated on request.
Approx. 6 km east of Ivanić-Grad.
People's Republic of Croatia (Narodna Republika Hrvatska / Народна Република Хрватск).
Pula: NDBN4453 E01353 (approx.)
Google MapsPL, 420 kHz
People's Republic of Croatia (Narodna Republika Hrvatska / Народна Република Хрватск).
Sarajevo: Butmir Airport (Međunarodni aerodrom Sarajevo)
Sarajevo/Butmir: NDBN4353 E01818 (approx.)
Google MapsSE, 405 kHz, 100 W
Operated on request.
People's Republic of Bosnia and Herzegovina (Narodna Republika Bosna i Hercegovina / Народна Република Босна и Херцеговина)
Skopje: (old Aerodrom)
Skopje was located in the former People's Republic of Macedonia (Народна Република Македонија). The old airport was located about 3 km southeast of the city center in today's district "Aerodrom".
Skoplje: NDBN4159 E02132 (approx.), 270/2.5 NM to field
Google MapsSQ, 370 kHz, 1200 W
Operated Monday-Friday 0800-1300, 1600-2200, Tuesday 0000-1830, Wednesday 2300-0200, 0700-2130, Thursday 0730-2000, Friday 0000-0300, 1030-2000, Saturday 0800-2200, Sunday 0830-1800.
For historical information only, do not use for navigation or aviation purposes!
Slavonski-Brod: NDBN4510 E01801 (approx.)
Google MapsSB, 340.5 kHz, 200 W
People's Republic of Croatia (Narodna Republika Hrvatska / Народна Република Хрватск).
Zagreb: Airfield Lučko (Zračno pristanište Lučko)
Zagreb/Lucko: NDBN4546 E01553 (approx.)
Google MapsLU, 399 kHz, 100 W
Operated on request.
People's Republic of Croatia (Narodna Republika Hrvatska / Народна Република Хрватск).
Zagreb/Lucko: NDBN4547 E01550 (approx.)
Google MapsZR, 367 kHz, 800 W
People's Republic of Croatia (Narodna Republika Hrvatska / Народна Република Хрватск).
For historical information only, do not use for navigation or aviation purposes!