The Brookdale Amateur Television Repeater System is owned and operated by the Brookdale Amateur Radio Club at Brookdale Community College in Lincroft, (Monmouth County) New Jersey. Conceived in 1991, the repeater has been operational since June 14, 1995, and serves the North Jersey Exterior Area on an input frequency of 426.250 MHz, and an output frequency of 439.250 MHz. The repeater uses a horizontally polarized antenna located 350 feet above ground level, and shares tower facilities with radio station WBJB-FM.
The purpose of the Brookdale Amateur Television Repeater System is to:
Take a look at what's new at the Brookdale ATV Repeater Web Site:
The Brookdale ATV Repeater System is a continuously evolving, long-term educational and research project that is supported by higher education and local industry. System upgrades and additions that have recently taken place include the following:
The current "to-do" list includes the following:
In order to maximize the repeater's service area to the greatest extent possible, the Brookdale ATV Repeater operates from an antenna located 350 feet above ground level, and provides reliable service to many areas of Monmouth County in New Jersey as well as areas of Brookyln and Staten Island in New York.
ATV reception may be as close as your favorite TV set. The following cable television (CATV) channels use frequencies within the 70-cm Amateur Radio band, and are popular for ATV communications:
57: 421.250 MHz (Popular ATV repeater output frequency)
CATV channel 58: 427.250 MHz (Fine tuning may permit reception of 426.250 MHz)
CATV channel 59: 433.250 MHz (Fine tuning may permit reception of 434.000 MHz)
CATV channel 60: 439.250 MHz (Most popular ATV simplex and repeater frequency)
Because of the
correlation between standard CATV frequencies used by cable
television systems and amateur radio operators involved in ATV
communications, television receivers and VCRs with "cable-ready"
tuners as well as some cable converters that cover "hyper-band"
channels may be used to receive ATV signals directly without the
need for an ATV downconverter. For example, the Brookdale ATV
Repeater transmits on 439.250 MHz, and may be received on CATV
channel 60. A low-noise GaAsFET preamplifier is required for
reception comparable to that of a good downconverter. A
horizontally polarized antenna tuned to 439.250 MHz and aimed
toward the repeater is required in either case.
In addition to providing subcarrier audio for reception on standard television receivers, the Brookdale ATV Repeater also frequency modulates its video carrier with audio using a deviation of 5 kHz to permit simple, low-cost reception with portable UHF-FM transceivers and scanners tuned to 439.250 MHz. When the system is not in use, the repeater transmits a video identification graphic every 10 minutes on 439.250 MHz to aid those setting up their home ATV stations. A morse code identification (N2SMT/R ATV) can also be heard during these periods.
Pocket-sized television receivers (Casio, Watchman, etc.) have also been known to receive 70-cm ATV signals directly with no modification simply by tuning below UHF channel 14 (470 MHz) in strong signal areas.
The frequency spectrum used by the Brookdale repeater may be further understood through inspection of the following diagram:
The Brookdale ATV Repeater has facilities for re-transmitting NASA Television programming during U.S. Space Shuttle missions as a public service to the amateur radio community. Such re-transmissions are permitted by the Federal Communication Commission through a special waiver originally requested by the Jet Propulsion Laboratory Amateur Radio Club in 1983. By granting permission to re-transmit Space Shuttle communications on amateur radio frequencies, the Commission recognized amateur radio operators' tremendous interest in space communications, and stated that such re-transmissions:
"afford amateur radio licensees a unique opportunity to become better informed about space communications and to feel a sense of participation in the United States space program. Further, re-transmission of the Space Shuttle communications gives amateur radio operators experience in setting up ad hoc links and networks around the country in order to carry the Shuttle information to interested amateurs. This experience would be invaluable in the event of a natural disaster or emergency in which similar communications links were required."
In recent years, many NASA astronauts have trained to become amateur radio operators, and have operated amateur radio stations from the Russian space station Mir, the U.S. Space Shuttles, and the International Space Station. NASA-TV coverage provided by the Brookdale ATV Repeater System has been invaluable to earth-based amateur radio operators wishing to communicate with astronaut/hams living and working in space. NASA-TV transmissions are normally carried by the Brookdale ATV Repeater System between the hours of 9:00 AM and 9:00 PM local time when the Space Shuttle is in orbit.
Being a platform for experimentation, research, and development that is supported by higher education and local industry, all engineering results obtained through the design, development, and operation of the Brookdale ATV Repeater System are published openly in an effort to promote learning, technical discussion, and to contribute to the advancement of the radio art.
Curious as to why repeater systems have time-out timers? Do they exist to discourage "repeater hogs", or are they simply a legal requirement? Are there any differences between the regulations regarding ATV and FM voice repeaters? Check out the July 1998 issue of CQ VHF magazine for an unbiased and informative discussion of repeaters and repeater timers by Rich Moseson, W2VU that was inspired by none other than the operation of the Brookdale ATV Repeater System.
The Brookdale ATV Repeater System received world-wide recognition when it was featured on the front cover of the October 1997 issue of CQ VHF magazine.
Click on image for more views of the repeater system.
More information on the Brookdale ATV Repeater System and its inspired projects may be found through the following links:
The list of web pages describing ATV communications continues to grow as repeater groups take to the Internet to share and exchange technical information about their systems:
These links provide very good information regarding Amateur Television communications and video in general:
Some hard-to-find information on Alford-Slot antennas may be found through the following links:
The following manufacturers of ATV and ATV-related communications equipment are on the Web:
The Brookdale ATV Repeater System is an on-going, long-term research project that is funded and supported by higher education and local industry. Special thanks go to the following individuals and organizations for responding to our needs and donating money, supplies, labor, and facilities without which this project would have never been possible:
Brookdale Community College is a non-profit organization. Donations to this project are greatly appreciated and may be tax deductible for some donors. Please send e-mail (kd2bd AT amsat DOT org) if you have any questions or feel you can contribute to this educational and public service oriented project.
This page is the recipient of several awards for design and content. It was last revised on November 4, 2009, and is updated as time permits. Thank you for your interest and support of the Brookdale Amateur Television Repeater System!
No animals were harmed, nor any Micro$oft products used in the creation or distribution of this page.
John A. Magliacane