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
On 4/10/2010 6:01 PM, [email protected] wrote:
I bought one of the Keyspan 4-port boxes some years ago, and it's never missed a beat. I mostly use it on Field Day with my laptop so I can have SatPC32 control my Ft-847, btu now that I've built both the Las Vegas Tracker *and* the Fox Delta unit, I'll be using it to control the radio and my Uaesu Az/El rotor. They've not inexpensive, but then you always get what you pay for! 73, Jim KQ6EA
On Apr 10, 2010, *Larry Gerhardstein* [email protected] wrote:
I hope someone can shed light. I'm using SatPC32, but that does not affect this problem. Awhile back I was forced to recycle both of my older computers that had one built in 9-pin serial port. Then, I connected the built-in port to the GS-232B rotor interface. I also purchased some HL USB-RS232 USB-to-Serial adapters, a cable with USB on one end and a 9 pin RS232 on the other end. I used this gadget to control my transceiver (which is a IC910H). Now I have a new computer which has no (zero) built in serial ports. I'm trying to use two of the USB-to-Serial gadgets and have run into trouble. If I disconnect all grounding back through the power, I can get one of the two to work, either the rotor or the rig-control, but not both at the same time. Without disconnecting grounding, neither work. It does not matter whether I'm plugging the USB ends directly into the computer, using a passive USB hub, or a powered hub--same result. All I have to do to get this to fail...is... Even if the USB ends are not plugged into the computer and the rig control box is powered off and unplugged from power, if I just touch the metal shield on the USB cable going to the rig control onto the shield connection in the computer or hub, that causes the rotor control to fail. When it fails, The azimuth reading on the G-5500 drops all the way to zero. The elevation meter is unaffected. It acts like a ground loop somewhere, but where and how? I've tried disconnecting the coaxes from the transceiver but no change. I'm thinking about scrapping these USB-to-Serial things and going to a 4-Port Keyspan box. HELP!! 73, Larry W7IN - DN27 in Plains, Montana _______________________________________________ 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
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
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Larry Gerhardstein