The Green Mountain Repeater Association
Serving Amateur Radio Since 1971
K3GMR 146.610 (-): Bladensburg
W3GMR 146.880 (-): Greenbelt
Repeaters
GMRA operates and maintains two VHF repeaters in Prince George’s County, Maryland which provide Amateur Radio communications for the Washington DC metropolitan and surrounding areas. The repeater frequencies and locations are below:
146.610 MHz Rx / 146.010 MHz Tx - Located at the top of the WSSC Water Tank at 4907 56th Place, Bladensburg, Md. 20710.
146.880 MHz Rx / 146.280 MHz Tx - Located at the top of the WSSC Water Tank at 211 Ridge Road, Greenbelt, Md. 20770.
The GMRA has recently upgraded our repeater equipment. The Greenbelt site's old Motorola 100-watt Micor repeater was replaced with a Motorola 125 watt Quantar repeater on 10/8/2023, and the Bladensburg site's Micor was replaced by another 125 watt Quantar repeater on March 10, 2024. Both repeaters are programmed with a PL Tone of 77 Hz, and unlike the past, the PL tone must be transmitted by your radio in order to be heard by the repeaters.
Each repeater site consists of a Repeater, Sinclair Duplexer, Link Communications Controller, battery or generator backup power, and a four element dipole vertical antenna at approximately 300 feet above sea level.
Both repeaters are dedicated to community support as required during times of emergencies. In this regard, GMRA is affiliated with the Amateur Radio Emergency Service (ARES) and the Radio Amateur Civil Emergency Service (RACES); the latter under the auspices of the Prince George’s County Office of Homeland Security.
It should be noted that the 146.880 MHz Repeater is connected to the EchoLink system full time.
ARES Logo is a registered service mark of ARRL, and is used with ARRL permission.
Each repeater has advanced features such as: Autopatch, Voice Playback Testing, Voice Mail, Instant Date/Time Retrieval, Touch Tone Testing, Automatic Announcements and Rapid Pre-programmed Touch Tone access to local/state/U.S. law enforcement agencies including 911. With the exception of the Voice Playback Testing, all advanced features are reserved for members only.
These are the two Motorola Micor 100-Watt Repeaters that were in operation for at both the Greenbelt and Bladenburg repeater sites. Unfortunately age took its toll on these machines, and because parts for them are no longer readily available, they were both replaced with more modern and reliable equipment.
In 2023 and 2024, after many, many years of faithful service the Micors were replaced by (the more modern) Motorola Quantar 125-Watt repeaters.
