While I don't have time this week to check the whole list that Bill posted, I
looked at the 1 kHz data for the K2 and the Orion. The figures for the K2
should be 67 and 116 dB (both preamp on). The worst case data on the Orion is
84 dB for IMD (main rx, preamp off) and 118 dB for BDR (preamp on).
Yes, the data for preamp on is usually *slightly* worse than with the preamp
off, but generally they are pretty close. I don't have an explanation for the
difference on the Orion as tested, but I would note that the 84 is a pretty
significant drop from the 2 kHz point data (90 dB). The BDR at 2 kHz was 5 dB
higher than at 1 kHz.
While I am on the general subject, the upcoming K2/KPA100 data will not include
any influence of the optional DSP unit, as that was not in the radio tested.
<Personal opinion> - I rarely offer my opinions on matters such as these
because everyone's situation is different, but I think it is important to keep
some perspective here. Let me share some thoughts on dynamic range versus real
world band conditions. It has been said that performance data at 1 and 2 kHz
is critical to performance on 160 and the other lower bands. In my opinion, I
think operators need to ask themselves some questions on this.
Dynamic range is a measure of the difference between the weakest signal that
can be received and the strength of a strong signal that is interferring. The
amount of dynamic range that is needed is therefore dependent on how weak a
signal you want/need to hear. When the band gets *really* crowded with S9+40
signals, are you honestly trying to pick out signals that don't even move the S
meter? I doubt this is true for most operators.
If the radio is acting like it is overloading, then attenuation is called for -
that is why radios have this feature. If you are trying to copy an S5 with
some S9+ interferers, then try turning off the preamp and adding 6 or 10 dB of
attenuation. Yes, the S5 will no longer move the meter, but the radio will
have less problems with overload and IMing.
73, Michael, KC1SX
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