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

Thu, 29 Jan 2004 20:02:10 -0600

Agreed

The ARRL Lab Tests are great and useful for stock radios

I suspect many on this list do not run a stock radio.  The lab reports
become a
comparison rather then reality.  I go and find outside tests done by folks
like W8JI http://www.w8ji.com/receiver_tests.htm
Are there others publishing receiver tests????????????????
and most of the Lab Tests were done on early models (example 1000D which got
pin diode change in later models)

73 W5AJ

----- Original Message ----- 
From: "Bill Tippett (by way of [email protected])" <[email protected]>
To: <[email protected]>
Sent: Thursday, January 29, 2004 5:32 PM
Subject: [1000mp] ARRL data - 1 kHz IMD and BDR performance

         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

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