Joining the ranks of FM translators greatly expanding the AM listening audience is WROL 950 Class D AM on 100.3 FM. WROL’s 5kW day signal from Rumney Marsh Reservation in Saugus is greatly attenuated to 90 watts at night to protect stations including:
- WIBX Utica, NY
- WKDN King of Prussia, PA
- CKNB New Brunswick, Canada
FM translators for AM
In general AM Revitalization FM translators for AM stations attempt to provide the AM daytime coverage 24 hours a day via 250 watt or less transmissions in the FM broadcast band. Having an FM signal can be a boon for station advertising revenue–provided the FM coverage is not disrupted by unexpected factors such as illegal “pirate” broadcasters. The Feb. 2017 R&O extended the 60 dBu (1 mV/m) FM translator contour to the greater of the AM 2 mV/m contour or 25 mile radius.
WROL W262CV 100.3 specifications
- 40 watts
- 42 21 46.35012 N 071 05 08.18621W (WGS84) Near the MIT Kendall MBTA stop, on the Marriott Hotel on Broadway (next to Microsoft NERD building).
- height above ground: 90 meters
WROL FM translator interference
The 100.3 pirates moved to 105.3, but WROL 100.3 faces severe challenges from, and presents new challenges to other licensed stations. Listeners to these existing stations may object to the new WROL 100.3 translator.
Pirates vs. FM translator
Pirate broadcasting is cheap and effective. $500 of equipment & antenna on top of a church or apartment building provides 3-5 miles of coverage radius. This has led to widespread pirate broadcasts in urban areas to service ethnic/language niche markets not economically served 24 hours a day by other means.
Like WJIB 101.3 FM, WROL 100.3 faces challenges inherent to low power FM broadcasting.
The Blue Hill Ave pirates have a cluster of three antennas for 87.75, 105.3 and formerly 100.3 MHz. The interference-free coverage and transmitter quality of 87.75 and 105.3 is nearly the same. Transmitter power appears to be in the 10-100 watt range.
50 kW WHEB is the primary limitation to coverage, particularly in the northeastern parts of Boston. However, one can merely switch to WROL 950 AM in northeast exurbs of Boston.
Licensed co-channel interferers include:
- WKIT Bangor, ME
- WHEB Portsmouth, NH 50 kW station that interfered with Dorchester 100.3 pirate, sometimes overriding pirate down to at least Chinatown area.
- W262CL Brattleboro, VT
- WKKB Middletown, RI
- WFFG Warrensburg, NY
- W262AS Bridgehampton, NY
For most listeners, co-channel WHEB is more limiting than first adjacent WBRS.
- WBRS 100.1 Brandeis Univ., Waltham, MA (25 watts)