[TenTec] Orion's Noise Floor versus K2

[Bill Tippett]

I wrote:
 >Threshold       Orion Noise Floor (unadjusted for 3 dB MDS definition):

21.28   138
31.91   138
47.87   138
63.83   138
95.74   139
191.48  139


 >To adjust for MDS = 3 dB S+N / N, 3 dB should be subtracted from the above
results.  This would yield about -135 dB MDS for 7 MHz which agrees nicely
with ARRL's measurement of -135.4 at 7.020 MHz.

         While I had my XG-1 out, I decided to measure my K2 also.  Using K2's
700 Hz Xfil setting, I measured the K2 Noise Floor at -141 dBm.  Adjusting
for the fact that K2's "700 Hz" filter is actually 340 Hz, I must subtract
the difference in Noise Bandwidth to get the equivalent measurement for
a 500 Hz BW (i.e. Orion).  10 log (340/500) = -1.7 dB, so the K2's equivalent
500 Hz Noise Floor would be about -139 dBm.  Then adjusting for 3 dB S+N / N,
I calculate the K2 at -136 dBm versus -135 dBm for Orion, which is close
to ARRL's measurement of -136 dBm for both (14 MHz, 500 Hz BW, Preamp On):

http://www.elecraft.com/K2_perf.htm#5%20kHz%20numbers

                                         73,  Bill  W4ZV