sensitivity spec not published

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Most other radios publish a sensitivity spec -- usually in the range of .2uV or below for the HF bands.  I notice on the spec sheets for the FLEX 6000 series that this spec is not provided.  Yet Sherwood measured it at .25uV.

Is this because there is some 'environmental specificity' (i.e. settings adjustments) that affect the sensitivity of the recievers?  or is the .25uV rating just not something Flex wants to necessarily publish?
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Posted 3 years ago

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Duane, AC5AA

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Sherwood measured 0.20 and 0.25, depending on whether the built-in preamp was used or not.
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Official Response
Flex-6000 Hardware Reference Manual - page 15 - Section 4.3 Receiver specs - lists the Sensitivity of all three radios.

you will need to do a download of the document.

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Jay / NO5J

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The sensitivity spec is published in the FLEX-6000-Hardware-Reference-Manual.
Sensitivity (Typical MDS in 500 Hz BW, Preselector OFF)  Preamp Off/10dB/20dB/30dB

For the 6300 its ... 
-121 dBm/-125 dBm/136 dBm/NA

For the 6500 it's ...
-121 dBm/-125 dBm/136 dBm/NA
            For the 6700 it's ...
-121 dBm/-125 dBm/136 dBm/-141 dBm 
Doing the conversions that results in ...

6300 .2 uV / .13 uV / NA

6500 .2 uV / .13 uV / .04 uV / NA

6700 .2 uV / .13 uV / .04 uV / .02 uV

The FLEX-6000-Hardware-Reference-Manual.pdf file is available in the Downloads at ...


73, Jay - NO5J

edited to add the conversion for the 6700s  -141 dBm spec I forgot to include

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KY6LA - Howard, Elmer

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Sensitivity tends to be a rather irrelevant number if the band noise normally exceeds the minimum sensivity level.

The following diagram shows how irrelevant most sensitivity numbers are for HF


MUch more important in the modern world are the phase noise numbers. Or how much internal noise the radio adds to the received signal. Flex 6700 has the best phase noise numbers.
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OK, thanks guys... I didn't think to look in the hardware manual.  I was just looking on the flexradio main site.