Jim,
We all know that good ideas are often developed independently but Keith Hoard and I both developed a balance plug redundant system on our own and used it at the Nats. But who knows, it was probably done earlier by others....
See the thread on the NSRCA website for a discussion and description of potential problems:
http://nsrca.us/forum/index.php?topic=167.0
John Gayer
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