On a recent afternoon, I was monitoring a conversation between two amateurs on 40 meter phone. They were discussing various transceivers that are on the market, weighing which one is better. As I followed their discussion, one of them excitedly boasted, "Well my radio, the Elecraft K3 is the best radio ever made, it really blows away all other radios costing so much more!" The other person inquisitively asked, how did you reach that conclusion? He responded, "I read it on the Sherwood list, only that computer radio...the Flex 6000 rates higher, which isn't a real radio. My K3 beats all the other ones costing so much more than my Elecraft!"
I laughed, first for hearing a grown man become so excited over a radio. Second, because he was so proudly making questionable claims. I thought "better for what"? In reality, it appears he does not have an adequate understanding of the test data (Sherwood Receiver Test Data) provided by Rob Sherwood, NC0B, and the minimal implication that high narrow spaced DR3 figures have, except under exceptional demanding conditions when using CW. I appreciate the service Rob Sherwood provides, both because it gives valuable information to the amateur community, and it serves as an independent data source beyond what is published by the ARRL/QST.
Nevertheless, I routinely hear the type of misleading discussion noted above on the amateur bands. Many times, I've heard individuals continue to incorrectly cite the implication of the data provided on the Sherwood list. It seems, many amateurs continue to relying heavily on the specific Third-Order Dynamic Range Narrow Spaced figures. Rationalizing, whatever radio is at the top of the list, it must be there because it is so much significantly better in all aspects than anything ranked lower.
However, there are many more factors involved in determining which certain transceiver is best for the individual. Moreover, I note that many of the transceivers that show exceptionally high narrow space DR3 numbers, do not always show an equal level of performance for wide spacing. A transceiver with higher narrow spaced DR3 figures, although better for the reception of CW signals during crowded band conditions, does not necessary make it a better transceiver for SSB. A transceiver that has higher wide spacing DR3 numbers, may be a better choice for someone that routinely operates phone. I suggest reading the document, Choosing a Transceiver Far from Simple by Rob Sherwood.
Rob Sherwood and I belong to the same Yahoo group for the Kenwood TS-990S. I have read a few of his responses to individuals seeking his advice about certain transceivers, and which one is better. Highlighted below is a recent typical response I've read from him. I believe it clarifies his position, and shows his opinion, that somewhat minimizes the importance of specifically high narrow spaced dynamic range figures for the transceivers presented on the table. Except under certain operating conditions, such as CW contesting or working a CW DX pileup, the higher narrow spaced DR3 figures are not that significant for routine operation. Hopefully, sharing his response here will give others a clear understanding, that most modern transceivers with good but lower narrow spaced DR3 figures, usually are fine for day to day operating.
NC0B -"The first thing to consider is what modes do you operate and what is the minimum performance needed for normal casual operating. For SSB I would say 75 dB is adequate most of the time. For CW I would say 85 dB is adequate most of the time. I would guess the 1200 I tested had a roofing filter that was somewhat wider and maybe off center. In any case the DR3 was 6 dB worse on one side than the other. On SSB much of the time adjacent channel splatter from a station 3 to 5 kHz away will be worse than the dynamic range of the radio. When would one prefer really large DR3 numbers? In a CW DX pile-up or CW contest. Also having really good phase noise (RMDR) would be really important on Field Day or your equivalent in Europe. The 3000 has phase noise issues on transmit. If you got a good deal on a radio and it is performing well for whatever your operating habits are, then just enjoy the radio. My two main radios are an old IC-781 with a DR3 of about 75 and a TS-990S which has an RMDR of 87 to 98. I enjoy both radios and they perform fine in the CW and SSB contests I operate. A K3S might be better, certainly on Field Day, but I prefer large radios with really good receive audio. They suite my needs which is all that matters.