> IN addition to bonding my radio ground rod to the electrical ground > (on the other side of the house), I will have my radio ground going > to my cable entrance plate. From there I have two tables and my > racks arranged in an U configuration with radio table facing the > racks six feet across the operating space. How should I run > grounds? My intention was to run a separate ground wire to a ground > buss on the radio table an another one to the racks both tied to the > copper bolt holding the outside ground wire.
All cables including power should come from the entrance panel ground to the desk. That should be the common ground point. The ground should come from the entrance panel to the desk with the wires and cables that are bundled or close spaced and parallel from the entrance point to the desk. > The only dc-isolated wiring in my shack is the soundcard audio lines > from radios to computers. Everything powered with ac is tied to the > safety 3rd wire in the house wiring. -HV thru a 100-ohm/25w resistor > , -24vdc, and -12vdc are all strapped to ground. All coax lines > exiting the room are grounded at the entrance plate. > See any problems with this? A 100 ohm 25 watt resistor is not a safe negative rail ground in a power supply. I see it in Handbooks, but whoever came up with that as a safety system should be severely beaten! Even with a 10 ohm clamp resistor, a B+ fault could pull a negative interconnect up to a few thousand volts above chassis. Capacitors can dump hundreds of amps while they discharge. Get some big diodes on that line on both ends and have a big chassis-to-chassis strap independent of the negative lead (interlocked if you can manage). A 100 ohm negative rail safety is like no safety clamp at all. Normal plate currents could produce lethal voltages, and a fault could drive the negative interconnect up to thousands of volts negative as capacitors discharge. 73 Tom ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
