FM RF exposure calculator

Unitsmetersfeet

Heights measured fromthe grounda rooftop people can reach

Distance from tower to check

Beam tilt or null fill: judge by the peaks (FCC method)

Your station

Channel201 (88.1 MHz)202 (88.3 MHz)203 (88.5 MHz)204 (88.7 MHz)205 (88.9 MHz)206 (89.1 MHz)207 (89.3 MHz)208 (89.5 MHz)209 (89.7 MHz)210 (89.9 MHz)211 (90.1 MHz)212 (90.3 MHz)213 (90.5 MHz)214 (90.7 MHz)215 (90.9 MHz)216 (91.1 MHz)217 (91.3 MHz)218 (91.5 MHz)219 (91.7 MHz)220 (91.9 MHz)221 (92.1 MHz)222 (92.3 MHz)223 (92.5 MHz)224 (92.7 MHz)225 (92.9 MHz)226 (93.1 MHz)227 (93.3 MHz)228 (93.5 MHz)229 (93.7 MHz)230 (93.9 MHz)231 (94.1 MHz)232 (94.3 MHz)233 (94.5 MHz)234 (94.7 MHz)235 (94.9 MHz)236 (95.1 MHz)237 (95.3 MHz)238 (95.5 MHz)239 (95.7 MHz)240 (95.9 MHz)241 (96.1 MHz)242 (96.3 MHz)243 (96.5 MHz)244 (96.7 MHz)245 (96.9 MHz)246 (97.1 MHz)247 (97.3 MHz)248 (97.5 MHz)249 (97.7 MHz)250 (97.9 MHz)251 (98.1 MHz)252 (98.3 MHz)253 (98.5 MHz)254 (98.7 MHz)255 (98.9 MHz)256 (99.1 MHz)257 (99.3 MHz)258 (99.5 MHz)259 (99.7 MHz)260 (99.9 MHz)261 (100.1 MHz)262 (100.3 MHz)263 (100.5 MHz)264 (100.7 MHz)265 (100.9 MHz)266 (101.1 MHz)267 (101.3 MHz)268 (101.5 MHz)269 (101.7 MHz)270 (101.9 MHz)271 (102.1 MHz)272 (102.3 MHz)273 (102.5 MHz)274 (102.7 MHz)275 (102.9 MHz)276 (103.1 MHz)277 (103.3 MHz)278 (103.5 MHz)279 (103.7 MHz)280 (103.9 MHz)281 (104.1 MHz)282 (104.3 MHz)283 (104.5 MHz)284 (104.7 MHz)285 (104.9 MHz)286 (105.1 MHz)287 (105.3 MHz)288 (105.5 MHz)289 (105.7 MHz)290 (105.9 MHz)291 (106.1 MHz)292 (106.3 MHz)293 (106.5 MHz)294 (106.7 MHz)295 (106.9 MHz)296 (107.1 MHz)297 (107.3 MHz)298 (107.5 MHz)299 (107.7 MHz)300 (107.9 MHz)

Antenna element typeEPA Type 1: ring-and-stub, or any other type (panels, vertical dipoles...)EPA Type 2: opposed "V" dipoleEPA Type 3: opposed "U" dipoleEPA Type 4: two-piece spiralEPA Type 5: three-piece or four-piece spiral

Radiation center height

Number of bays

Bay spacing, wavelengths

ERP horizontal, kW

ERP vertical, kW

Other FM stations on the same tower

Leave a station's channel at "(none)" to skip it. Heights are on the same tower, from the same surface.

Other station 1

Channel(none)201 (88.1 MHz)202 (88.3 MHz)203 (88.5 MHz)204 (88.7 MHz)205 (88.9 MHz)206 (89.1 MHz)207 (89.3 MHz)208 (89.5 MHz)209 (89.7 MHz)210 (89.9 MHz)211 (90.1 MHz)212 (90.3 MHz)213 (90.5 MHz)214 (90.7 MHz)215 (90.9 MHz)216 (91.1 MHz)217 (91.3 MHz)218 (91.5 MHz)219 (91.7 MHz)220 (91.9 MHz)221 (92.1 MHz)222 (92.3 MHz)223 (92.5 MHz)224 (92.7 MHz)225 (92.9 MHz)226 (93.1 MHz)227 (93.3 MHz)228 (93.5 MHz)229 (93.7 MHz)230 (93.9 MHz)231 (94.1 MHz)232 (94.3 MHz)233 (94.5 MHz)234 (94.7 MHz)235 (94.9 MHz)236 (95.1 MHz)237 (95.3 MHz)238 (95.5 MHz)239 (95.7 MHz)240 (95.9 MHz)241 (96.1 MHz)242 (96.3 MHz)243 (96.5 MHz)244 (96.7 MHz)245 (96.9 MHz)246 (97.1 MHz)247 (97.3 MHz)248 (97.5 MHz)249 (97.7 MHz)250 (97.9 MHz)251 (98.1 MHz)252 (98.3 MHz)253 (98.5 MHz)254 (98.7 MHz)255 (98.9 MHz)256 (99.1 MHz)257 (99.3 MHz)258 (99.5 MHz)259 (99.7 MHz)260 (99.9 MHz)261 (100.1 MHz)262 (100.3 MHz)263 (100.5 MHz)264 (100.7 MHz)265 (100.9 MHz)266 (101.1 MHz)267 (101.3 MHz)268 (101.5 MHz)269 (101.7 MHz)270 (101.9 MHz)271 (102.1 MHz)272 (102.3 MHz)273 (102.5 MHz)274 (102.7 MHz)275 (102.9 MHz)276 (103.1 MHz)277 (103.3 MHz)278 (103.5 MHz)279 (103.7 MHz)280 (103.9 MHz)281 (104.1 MHz)282 (104.3 MHz)283 (104.5 MHz)284 (104.7 MHz)285 (104.9 MHz)286 (105.1 MHz)287 (105.3 MHz)288 (105.5 MHz)289 (105.7 MHz)290 (105.9 MHz)291 (106.1 MHz)292 (106.3 MHz)293 (106.5 MHz)294 (106.7 MHz)295 (106.9 MHz)296 (107.1 MHz)297 (107.3 MHz)298 (107.5 MHz)299 (107.7 MHz)300 (107.9 MHz)

Antenna element typeEPA Type 1: ring-and-stub, or any other type (panels, vertical dipoles...)EPA Type 2: opposed "V" dipoleEPA Type 3: opposed "U" dipoleEPA Type 4: two-piece spiralEPA Type 5: three-piece or four-piece spiral

Radiation center height

Number of bays

Bay spacing, wavelengths

ERP horizontal, kW

ERP vertical, kW

Other station 2

Channel(none)201 (88.1 MHz)202 (88.3 MHz)203 (88.5 MHz)204 (88.7 MHz)205 (88.9 MHz)206 (89.1 MHz)207 (89.3 MHz)208 (89.5 MHz)209 (89.7 MHz)210 (89.9 MHz)211 (90.1 MHz)212 (90.3 MHz)213 (90.5 MHz)214 (90.7 MHz)215 (90.9 MHz)216 (91.1 MHz)217 (91.3 MHz)218 (91.5 MHz)219 (91.7 MHz)220 (91.9 MHz)221 (92.1 MHz)222 (92.3 MHz)223 (92.5 MHz)224 (92.7 MHz)225 (92.9 MHz)226 (93.1 MHz)227 (93.3 MHz)228 (93.5 MHz)229 (93.7 MHz)230 (93.9 MHz)231 (94.1 MHz)232 (94.3 MHz)233 (94.5 MHz)234 (94.7 MHz)235 (94.9 MHz)236 (95.1 MHz)237 (95.3 MHz)238 (95.5 MHz)239 (95.7 MHz)240 (95.9 MHz)241 (96.1 MHz)242 (96.3 MHz)243 (96.5 MHz)244 (96.7 MHz)245 (96.9 MHz)246 (97.1 MHz)247 (97.3 MHz)248 (97.5 MHz)249 (97.7 MHz)250 (97.9 MHz)251 (98.1 MHz)252 (98.3 MHz)253 (98.5 MHz)254 (98.7 MHz)255 (98.9 MHz)256 (99.1 MHz)257 (99.3 MHz)258 (99.5 MHz)259 (99.7 MHz)260 (99.9 MHz)261 (100.1 MHz)262 (100.3 MHz)263 (100.5 MHz)264 (100.7 MHz)265 (100.9 MHz)266 (101.1 MHz)267 (101.3 MHz)268 (101.5 MHz)269 (101.7 MHz)270 (101.9 MHz)271 (102.1 MHz)272 (102.3 MHz)273 (102.5 MHz)274 (102.7 MHz)275 (102.9 MHz)276 (103.1 MHz)277 (103.3 MHz)278 (103.5 MHz)279 (103.7 MHz)280 (103.9 MHz)281 (104.1 MHz)282 (104.3 MHz)283 (104.5 MHz)284 (104.7 MHz)285 (104.9 MHz)286 (105.1 MHz)287 (105.3 MHz)288 (105.5 MHz)289 (105.7 MHz)290 (105.9 MHz)291 (106.1 MHz)292 (106.3 MHz)293 (106.5 MHz)294 (106.7 MHz)295 (106.9 MHz)296 (107.1 MHz)297 (107.3 MHz)298 (107.5 MHz)299 (107.7 MHz)300 (107.9 MHz)

Antenna element typeEPA Type 1: ring-and-stub, or any other type (panels, vertical dipoles...)EPA Type 2: opposed "V" dipoleEPA Type 3: opposed "U" dipoleEPA Type 4: two-piece spiralEPA Type 5: three-piece or four-piece spiral

Radiation center height

Number of bays

Bay spacing, wavelengths

ERP horizontal, kW

ERP vertical, kW

Calculate

Which element type is my antenna?

The FCC's list of antenna models for each EPA element type (OET Public Notice DA 16-340, Appendix B; not an endorsement). Anything not listed, such as panels or vertical dipoles, is treated as Type 1.

• Type 1: BEXT TFC1K; Dielectric DCR-L; ERI ECFM, G4CPH, G4CPL, G4CPM; LPC 37CP, 37M, 1105; Harris FMC, FMS; NiCOM BKG88; Shively 6814, 6810, 6813, 6812; SWR FM1
• Type 2: BEXT TFC2K; ERI 100A; Jampro JCPB, JHCP, JHPC, JLLP, JLPC, JMCP, JMPC, JSCP, JSLP; MCI AT12; NiCOM BKG77; PSI FML; RFS 828; Shively 6832; SWR FM3, FM10, FMEC, FMU
• Type 3: Armstrong FMA-737; BE BEMP, BESP; ERI G5CPM, G5CPS; DI LP, LPX, MP, MPX, SHP, SHPX; Harris FMH, FML, FMP, FMX; Jampro JBCP
• Type 4: Armstrong FMA-707/727; Dielectric CCA, DCR/HDR-C, DCR/HDR-H; Jampro JLCP; RFS CPF
• Type 5: Dielectric DCR-G, DCR/HDR-M, DCR-Q

How this calculator works

• It is the FCC's FM Model (OET, updated in Public Notice DA 16-340, March 31, 2016), ported line for line and checked against the FCC's own results. It predicts the field from an FM antenna at 2 m above a flat surface.
• Each bay is one of five element types the EPA measured in 1985 (EPA 520/6-85-011). The bays are spaced evenly around the radiation center, fed with equal power and phase, and their fields are added along each bay's own path. A fixed ground-reflection factor (1.6, so 2.56 in power) is applied.
• Beam tilt and null fill. Equal phase means the model can show deep nulls a tilted or null-filled antenna doesn't have. The FCC's advice is to draw a line through the curve's peaks ("connect the dots"), which won't underestimate the field for common tilt and null-fill settings (DA 16-340). Tick the box and the result is judged on that line.
• Several FM stations on one tower. Their power densities add at each point, and all FM stations share the same limit. The table shows who shares responsibility where the total is over (47 CFR 1.1307(b)(5)(i)). TV, cellular and other services on the same tower have different limits and antennas; this calculator covers FM only.
• Rooftops. Measure the heights from the roof and the results are for people standing on it. The FCC cautions that the model may not be accurate near rooftops or for antennas close to the surface; measure there.
• Limits are from 47 CFR 1.1310(e)(1), Table 1, for 30-300 MHz: 0.2 mW/cm² (200 µW/cm²) for the general population and 1.0 mW/cm² (1,000 µW/cm²) for trained workers in controlled areas.

The FCC's own tool: FM Model.

For planning. Not a product of the FCC; it does not replace measurements where they are needed.