[CQ-Contest] What am I Missing

Pete Smith pete.n4zr at gmail.com
Tue Feb 28 10:47:52 EST 2006


I am perplexed.  After reading the review of the FTDX9000 Contest in the March QST, I can't imagine why a contester would buy one of these, even given the adoring subjective comments by the ARRL reviewers.  For the $5700 basic price, you could buy 2 or 3 MPs loaded with Inrad filters.  Combine that with Yaesu's policy of requiring you to buy any options at the time of purchase (meaning either huge, expensive stocks or a long wait), and I think the market for used MPs will be in good shape for a long time.   

Just for fun, I compared the ARRL Lab's receiver performance stats for the 9000 Contest with those for two different MPs with the Inrad roofing filter.  Aside from third-order intercept, not stated in the ARRL's MP/roofing filter review, both MPs walk all over the 9000 in almost all of the parameters of particular interest to us.  The third-order intercept for a stock Mark 5 field at 5 kHz spacing is pretty low; at 20 KHz it is comparable to the 9000's at 5 KHz.  it would be interesting to know what difference the roofing filter would make in this measurement.

View the table below with a monospaced font for best results:

				MkV/1000MP				FTdx9000 Contest
Data taken on 20 meters 
with pre-amp off

Noise Floor			–130 dBm/-126 dBm	 		-123 dBm

Blocking Dynamic Range		20 kHz   146 dB*/141 dB			128 dB*
				5 kHz    130 dB*/128 dB			119 dB*
				2 kHz    105 dB/108 dB			 97 dB
				1 kHz	 106 dB(1)/103 dB*		Not stated

IMD Dynamic Range		20 kHz 93 dB/100 dB			101 dB
				5 kHz  89 dB*/90 dB*			 98 dB*
				2 kHz  79 dB*/71 dB			 78 dB*			
				1 kHz  69 dB*/68 dB*			Not stated

*Measurement was noise limited at the value indicated.
(1) Some filter blow-by was noted on this measurement.


73, Pete N4ZR




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