I got fed up with noisy power supplies to here is my solution.
1. A linux computer runs Predict as a server 2. A perl script wakes up every minute, and asks predict if ISS is above the horizon. 3. If ISS is above the horizon, a command is sent to a parrallel port control card. 4. The control toggles a relay 5. The relay action turns off the battery charger and engages the radio 6. When the ISS is below the horizon once more, the script turns off the relay. 7. The radio turns off and the battery charger re-engages. 8. The radio has a 30 minute time out set as well to guard against problems.
So far it works really well.
The rack clicks and comes to life as ISS rises and goes back to sleep when it descends.
Here is a photo.
http://www.tech-software.net/rack_psu.jpg
I am not having much luck with the helix's i have built the front to back seems bad.
I have however had great success on 2m, with an 8 element quad.
Cheers
---------------------------------------------------------------------------- Andrew Rich VK4TEC [email protected] http://www.tech-software.net