Problem reported in this thread solved. Bought and installed two optical isolators. One in ICOM serial line and one in GS232/G5500 serial line. Rotor position now reading correctly, but there was one more issue. Cables that I believed to be straight through were not; they were null modem. Should have used an ohm meter right away. Tests of pins 2 and 3 at both ends proved what the cables really were.
A warning: two null modem cables back-to-back to not make a straight through cable. But there still are more problems with my sat system, which I will discuss in further posts. Larry W7IN On 4/15/2010 6:41 PM, Larry Gerhardstein wrote: > Jim, et. al., Thanks for the advice. However, after installing the > USA-49WG and driver install for Windows 7 with help from Tripp Lite > technical support, my system still does the same thing. I plug the > serial cables to both rotor and transceiver digital interfaces and then > to the 49WG and the same thing happens. Azimuth meter drops to zero and > there is no control. Further it is now working worse than before, as I > have neither control of rotor or transceiver. If measure the voltage > between metal shields of the two cables, there is about 2 volts there. > It sure looks like a ground loop, but where and how. I have no idea at > this point. In 56 years a ham operator, I've never run into anything > like this. Maybe RS232 isolators would fix this??? Seems like overkill. > > Larry W7IN > _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
