Receive performance has been one of the top criteria for transceiver selection by hams for decades. As the well-worn phrase goes, “if you can’t hear ‘em, you can’t work ‘em.” Rob Sherwood has been conducting bench tests on the receive performance of rigs for several decades, accepts no advertising, and does not, with rare exception, accept transceivers or receivers directly from manufacturers for testing. He is adamant about independence in his assessments. In addition, his tests are “worst case” assessments by design. In general, his resulting Sherwood Tables of Receiver Tests are considered the gold standard by many hams, particularly contesters.
Sherwood publishes his tables on his Sherwood Engineering website,1 sorted by values resulting from the narrow dynamic range (NDR) test. He strongly believes that this is the single best criterion for the CW contest operator. He has long been an active contester. His disagreement with the ARRL Lab review of a Drake R4C receiver led him to construct his own set of bench tests which he believed to be a more valid set. The rest, of course, is history from which the amateur radio world has benefited greatly.
Beyond the NDR
But for hams who are not CW contest operators, this single criterion of using the NDR rank-order as a decision rule may not yield an optimal conclusion. As he has stated numerous times, this is perhaps the most common source of frustration for viewers of Rob’s tremendous resource. The difference between rigs in sequence may not be numerically that different or, consequently, substantively differentiated. This produces much debate and potential confusion about the bench test results, as evidenced by reading blogs, forums, and just listening in
