[TenTec] [Fwd: "Being a Contrarian . . ."]

[Bill Tippett]

Rob NC0B:

 >I would say for CW, 80 dB DR3 is adequate most of the time.
Certainly 85 dB is adequate on CW virtually all the time.
W8JI and I completely agree on this.

         I am still mystified by RSGB's measurement
of the Sub-RX in Orion II.  It shows 85 dB IMDDR3 at
1 kHz versus 96 dB for the Main Rx.  85 dB at 1 kHz
would be a *phenomenal* result for a 20 kHz roofing
filter if true.  ARRL measured 67 dB at 2 kHz versus
95 dB for the Main, which is consistent with their
measurements of the original Orion.  I wonder if
G3SJX may have made a transposition of his data
(table of close-in IMD on page 2 of the article).

         For anyone who thinks IMD is not important,
they can hear it by tuning around with the Sub-RX
in the next CW contest and compare vs the Main-RX.
There is a HUGE difference.  Orion's Sub-RX has IMD
performance in the same ballpark as rigs like the
IC-756PROIII (i.e. both use ~15 kHz roofing filters).

                                 73,  Bill  W4ZV