The amateur television (ATV) repeater transmits in the 70 centimeter band and receives in the 70 cm and higher amateur bands. It transmits the same NTSC-compatible AM video and sound that we receive on our televisions from broadcast and cable companies throughout the United States. This format is also in use in Canada, Mexico and Japan. The repeater receives video transmissions that are NTSC- compatible and transmissions that are frequency modulated similar to commercial analog satellite television.
The repeater transmits on 427.25 MHz (cable channel 58). It receives on 434.0 MHz (cable channel 59) , 910.25 MHz (also NTSC-compatible AM), and 1255 MHz (FM). Click HERE for the repeater frequency plan. It is located in Holiday, Florida. Click HERE for a full size map showing it's location. The transmit antenna is a DB Products DB-420 16-element UHF vertical installed 1,175 feet above ground.
It's effective radiated output power is 250 watts. The transmitter consists of a PC Electronics TXA5-70 exciter, FM-A5f sound subcarrier generator, and PA5 10-watt amplifier, an RF Concepts 4-110 100-watt power amplifier and Spectrum International PSf421-ATV vestigial sideband filter. Transmitter output power is 100 watts peak-envelope-power (PEP) on the sync tips.
The 70 and 33 cm receivers consists of PC Electronics TVCX downconverters and VRC-45b 45.75 MHz IF receiver/demodulators. The 23 cm receiver consists of a PC Electronics TVCX-23 downconverter and a High Frequency Technology HFT IF70 70 MHz IF FM receiver/demodulator.
All repeater operation is handled by a Micro Computer Concepts VS-90 video repeater controller. It listens on 145.995 for DTMF commands. Click HERE for a block diagram of the repeater and HERE for current repeater status.
Some of the fun things we can do on the repeater: watch NASA Television's continuous coverage of space shuttle missions, transmit live video of ourselves and ham shacks or home video tapes of family fun, transmit views from waterproof tower cams for weather reporting or enjoying the beautiful women rollerblading down the Pinellas Trail, send pictures from various checkpoints during the road races and triathalons that we cover, broadcast club meetings for those that can't attend, broadcast ham radio classes. Now, don't you love amateur radio?
The future plans look very exciting. Thanks to Scott Miller, WD4MND, Mike Whitmore, WB8ONY, and Ron Wright, N9EE for their knowledge, experience, and resources in helping Jim Lemke, KD4KSI and I, Dana, K4LK, put the repeater back on the air. It is a great pleasure to work with such talented communications professionals. Our new partnership can only get better and better.
For more information about amateur television and the repeater, access the following links:
ATV Repeater:
Reference Material:
Links of interest to ATVers:
(This new page is under construction, so please pardon our dust).
Last update: 4 July 2003
