On 6/3/2016 10:03 AM, Don Wilhelm wrote: > The bonding wire eliminates much of that "pin 1 problem".
That is only true of two conditions are met: 1) the case is metal (conductive) 2) the case is tied to the power supply return (negative) at the power input. Otherwise, *bonding* tends to circuit board "ground plane" to circuit board "ground plane" and spread the noise through all of the connected devices - particularly if the device does not have a single "ground post" and the bonding is connected haphazardly to whatever case/chassis/connector screw is handy. 73, ... Joe, W4TV On 6/3/2016 10:03 AM, Don Wilhelm wrote:
Joel and all, Use BONDING rather than "Grounding" You may create more noise problems by attempting to "ground" everything. "Ground" is not a sink for noise and RFI problems, it is only protection for AC mains safety and lightning surges. Grounding will not carry away noise that is picked up on the shields of connecting cables, and in some cases may even make it worse. Yes, you should have a good Mother Earth ground in the hamshack, but it will likely not help with noise, hum and buzz problems. Take the advice of Jim Brown K9YC and BOND the equipment enclosures together. In other words, connect the KX3 and PX3 enclosures together with a heavy wire or braid. What you accomplish by bonding is to take a major portion of the noise that would appear on the cable shield(s) and conduct it to the outside of the enclosure so that it does not get onto the ground plane of the PC board. We did not have that problem years ago when all connectors were mounted to a metal enclosure. The outside of the cable shield braid was connected to the outside of the enclosure. But modern construction techniques connect the shields of cables to the ground plane of the PC board and not to the enclosure. So any noise present on the outside of the cable shield is conducted into the electronics. The bonding wire eliminates much of that "pin 1 problem". 73, Don W3FPR
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