The following list contains the aeronautical radio beacons that were active in Portugal in the mid of the 1950s. All information is outdated and may not be used for navigational purposes.
At this time there were only non-directional beacons (NDB) and Ranges. The airports of Lisbon, Porto and Santa Maria were equipped with an Instrument Landing System (ILS). In the early 1950s, there was also a Eureka beacon and a Standard Beam Approach (SBA) system (formerly Lorenz system) in Lisbon.
Radio beacons and airways in 1955

North (Source: DoD)

South (Source: DoD)

Azores (Source: DoD)
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!
Alverca: Air Base
Alverca: NDBN3853 W00902 (approx.)
Google MapsAR, 262 kHz
Aveiro: Airfield (São Jacinto, Aeródromo Municipal de Aveiro)
Aveiro: NDB (PNAS)
N4039 W00845 (approx.)
Google MapsAV, 291.9 kHz
Operated in clear weather H+14, 44; in fog: H+02 and every 6 minutes.
Aveiro: NDB (PNAS)
N4039 W00845 (approx.)
Google MapsAI, 396 kHz
Aveiro: NDB (PNAS)
N4039 W00845 (approx.)
Google MapsCTA, 318 kHz
Operated on request.
Barcarena: NDBN3843 W00916 (approx.)
Google MapsLS, 355 kHz
Berlengas: NDBN3925 W00930 (approx.)
Google MapsIB, 287.3 kHz
Berlenga Grande. Operated in clear weather H+04, 34; in fog H+04 and every 6 minutes.
Cape Roca: NDBN3847 W00930 (approx.)
Google MapsRC, 308 kHz
Cabo da Roca. Operated in clear weather H+06, 36; in fog H+00 and every 6 minutes.
Coruche: NDBN3858 W00832 (approx.)
Google MapsCR, 389 kHz
At the intersection of airways ADR (Advisory Route) 527, ADR 548 and ADR 549.
For historical information only, do not use for navigation or aviation purposes!
Flores: NDBN3920 W03118 (approx.)
Google MapsFS, 308 kHz, 200 W
Horta: Seaplane Station
Horta: NDB (civ)
N3832 W02838 (approx.)
Google MapsFY, 294.5 kHz
Azores (Açores). Operated on 30 minutes request to Santa Maria.
Lajes (Base Aérea das Lajes, Base Aérea Nº 4, BA4)
Lajes: NDBN3842 W02721 (approx.)
Google MapsLJ, 396 kHz, 100 W
Lajes: Racon (USAF)
N384456 W0270424 (approx.), 247°/0.42 NM to field
Google Maps2, 9310 MHz
Operated continuously.
Runway 16:
Lajes: NDBN3846 W02707 (approx.)
Google MapsGP, 341 kHz, 400 W
In the early 1950s, this beacon was a Range (courses: 073°, 163°, 253° and 343°)
Runway 34:
Lajes: NDBN3844 W02705 (approx.)
Google MapsDK, 273 kHz, 100 W

Range approach to Lajes airfield (Azores) in 1951 - The Range is located immediately to the northwest of the airfield. The four courses and the A/N sectors of the Range are depicted on the map (Source: DoD)
Leça: NDBN4112 W00843 (approx.)
Google MapsLC, 291.9 kHz
Leça da Palmeira. Operated in clear weather H+16, 46; in fog: H+04 and every 6 minutes.
Lisbon: Airport (Aeroporto de Lisboa, Aeroporto da Portela, Aeroporto Humberto Delgado)
Lisbon: Eureka
Lisbon: Beirolas NDBN3846 W00906 (approx.), 281°/1.6 NM to field
Google MapsLB, 338 kHz, 450 W
Lisbon: SBA
Runway 23:
Lisbon: RangeN3849 W00906 (approx.), 225°/3.0 NM to field
Google MapsPL, 382 kHz
The four predefined courses to the range were 045°, 135°, 225° and 315°.
Lisbon: ILS 23PA, 109.5 MHz
Operated on request.
Lisbon: LOM 23225°/4.0 NM to THR 23
Locator: OL, 224 kHz
Operated on request.
Lisbon: LMM 23223°/0.57 NM to THR 23
Locator: L, 207 kHz
Operated on request.
Lisbon: IM 23
225°/0.03 NM to THR 23
Dots, 75 MHz

ILS approach to Lisbon runway 23 in 1954 - In the center of the circle is the Lisbon Range. (Source: DoD)

Lisbon Airport in 1954 (Source: DoD)
Mont D'Or: NDBN4145 W00852 (approx.)
Google MapsMR, 291.9 kHz
Montedor. Operated in clear weather H+12, 42; in fog: continuous.
Montijo: Air Base
Montijo: NDB (PAF)
N3842 W00902 (approx.)
Google MapsMIO, 322 kHz, 50 W
For historical information only, do not use for navigation or aviation purposes!
Ota: Air Base
Ota: NDB (PAF)
N3905 W00857 (approx.)
Google MapsOTA, 378 kHz
Portalegre: NDBN3918 W00725 (approx.)
Google MapsPM, 364 kHz
On airway ADR (Advisory Route) 527.
Porto: Airport
Runway 18:
Porto: NDB
181°/2.2 NM to field
PO, 327 kHz, 350 W
Porto: ILS 18PR, 109.5 MHz
Operated on request. On test.
Porto: MM 18
181°/0.6 NM to THR 18
Dots Dashes, 75 MHz
Porto: IM 18
181°/0.43 NM to THR 18
Dots, 75 MHz
Sagres: NDBN3700 W00857 (approx.)
Google MapsSA, 277 kHz
No specific working hours
Santa Maria: Airport
Runway 01:
Santa Maria: Range/Z MarkerN3657 W02510 (approx.)
Google MapsRange: STA, 240 kHz
Z Marker: 75 MHz
The four predefined courses to the Range were 010°, 100°, 190° and 280°.
Runway 19:
Santa Maria: NDBN3659 W02511 (approx.), 190°/1.0 NM to to field
Google MapsSMA, 323 kHz
Santa Maria: ILS 19
SM, 110.3 MHz
Santa Maria: MM 19
190°/0.61 NM to THR 19
Dots Dashes, 75 MHz
Santa Maria: IM 19
190°/0.04 NM to THR 19
Dots, 75 MHz

Santa Maria, Azores, 1954: ILS approach to runway 19 - South of the field is the Range with its four courses and the A/N sectors. (Source: DoD)
Santana: Airport (Aeródromo de Santana)
Santana: NDB (PAF)
N3749 W02534 (approx.)
Google MapsSML, 371 kHz, 1200 W
Rabo de Peixe, Ribeira Grande, Azores (Açores).
Sintra: Air Base (Base Aérea de Sintra, Base Aérea Nº1, BA1)
Sintra/Granja do Marquês: NDBN3852 W00921 (approx.)
Google MapsSTR, 371 kHz
For historical information only, do not use for navigation or aviation purposes!
Vilar Formoso: NDBN4036 W00649 (approx.)
Google MapsPB, 268 kHz
At the northern end of Advisory Route 549.
For historical information only, do not use for navigation or aviation purposes!