[1000mp] ARRL data - 1 kHz IMD and BDR performance

[Bill Tippett]

         For my own curiosity I decided to look at 1 kHz IMD and BDR
performance using the swept graphs in ARRL's Expanded Test Reports.
I confirmed with KC1SX who does ARRL's tests that the closest signal
spacing was at 1 kHz in the swept IMD and BDR graphs (typically
found around page 20 of the ETR reports).  Why 1 kHz?  Because in a
typical contest, it is not unusual for strong interfering signals to be
spaced at 1 kHz or even closer.  Also, it is not simply two strong
interfering signals...many weaker ones can contribute to the problem.

"Always remember actual overload is the result of the vector sum of
signals in the passband of the system at that point. One way to look
at it is that overload is an accumulated power problem, not an
absolute level problem with one signal. This means a great number of
weaker signals can cause the same problem as a few strong ones."
http://www.w8ji.com/how_to_check_signals.htm

	The only exception to 1 kHz measurements below is for the
original MP, done in 1996 before KC1SX took over ARRL's testing.

Listed in order of 1 kHz IMDDR3 results:

Radio                      IMDDR3                BDR

TT Orion                	84 dB           	119 dB
FT-1000MP*              	78*                    108*
IC-756PRO              	75              	104
IC-775DSP               	73              	103
TT Omni VI+                71              	 85
IC-746PRO               	70              	 92
IC-746                         70              	 88
IC-756PRO2             	69              	 92
FT-1000MkV              	69              	100
Elecraft K2                  66              	115
TS-870                        63              	 87
FT-1000Field               60              	 88
JRC NRD-535              50              	 86
IC-756                         50              	 85

*FT-1000MP IMD @ 2 kHz and BDR @ ~500 Hz

Source: http://www.arrl.org/members-only/prodrev/reports.html

                                         73,  Bill  W4ZV