There have been a number of recent posts here regarding noise problems with a new computer. I am reminded of a problem years back with a trusty old 386SX system that had given me excellent service for a number of years. It was eventually replaced with a 486DX system in the pursuit of improved performance (to carry all the overhead of recent releases of WinDoze). The old 386 was then pressed into service in my amateur radio station to create a TCP/IP node and server system on the local amateur packet radio links. When I installed the packet radio modem card, I could not get it to work because it thought that there was a signal on the air all the time and, thus, would never switch to transmit mode. To make a long story short, I found that the +5V power in the old 386SX was covered with random noise like crud that was getting into the packet modem chip and creating false signals. A new orignal equipment power supply was purchased and installed, same problem! The problem was traced to lack of loading on the power supply that was created when most of the peripheral boards were removed and moved to the new 486DX system. The solution was to install a couple of used peripheral cards in spare slots untill sufficient load was created to stabilize the power supply. Therefore, I strongly recommend that the gentleman with the noisy computer get a good scope on the power supply lines and look for excess noise. Expect to see some residual switching noise, but anything excessive such as >100 mv P-P should be suspect. Good luck, Bob Smith -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>