There have been a couple of recent posts about a G5500 voltage drift issue and some solutions. I'd like to thank those gentlemen for the posts and the solutions. I am in a unique position to be able to work with nine G5500 rotors side-by-side in preparation for the Teachers Institute II that I will hold at the end of the week. I noticed the same warm-up/calibration issue mentioned in the posts. I discovered that it took on average 10 minutes of warm up time for the voltage to stabilize, and this voltage is the reference on which the antenna position indications are based. The difference between the cold start and warm up position was around 10 degrees for AZ and 4 degrees for EL. Minor but irritating. I thought I'd try the easiest solution suggested first (changing the output cap on the regulator to .1uF) before I tried the more dramatic solution of changing out the voltage regulator. I simply tack soldered the .1uF cap on the exposed leads of the existing .01uF cap, and it worked like a charm. All nine rotor controllers fire up at 6.12 volts and hold that voltage throughout the operation of the rotor. This sure will make instruction of rotor setup and calibration a heck of a lot easier. Thanks for the suggests.
Mark Spencer, WA8SME
ARRL-The national association for Amateur Radio
Education and Technology Program Coordinator
mspencer@arrl.org
http://www.arrl.org/FandES/tbp/
530-495-9150