WB8ELK/W9PRD and the WB9IHS/W9PRD have performed balloon experiments using Wyman Research transmitters. The higher power of this transmitter makes it possible to find a lost transmitter by triangulation, if the 2 meter beacon fails. The 2 meter transmitter did fail on two occasions. Many future flights in the Ohio Valley by WB9IHS and his sponsored high school science class groups will use Wyman transmitters.
The on-carrier audio and the sub-carrier audio capability will make it possible for 2 meter hams on the ground to talk through the balloon ATV transmitter by means of an on-board 2 meter receiver, regardless of whether or not they are receiving pictures. The on-carrier audio on the Wyman Research transmitter makes this possible, if you have a handheld on 2 meters and one on 439.25 MHz. This was a "first" by WB9IHS using the sophisticated Wyman equipment.
On-carrier audio is 100 times more powerful than the normally used sub-carier audio. Unlike sub-carrier audio, it is not necessary to receive a picture while listening to the audio.
Although AM ATV is normally used for balloon and model airplane experiments, ATV hams could improve their systems by using the FM ATV mode. FM is far superior to AM and is extremely useful at 900 and 1200 MHz. Multipath fading is reduced, and the antennas and hardware are smaller. Wyman has a small transmitter (3" x 3" x 2.5") that can be mounted in model airplanes. Don't miss out on a far superior method of transmitting video from your plane or balloon.
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Last updated 1999 February 28.