[Elecraft] Comparison: K3 and SDR 5000A

[Bill Tippett]

KD8K:

 >The K3's close in numbers will be around the same is the 5000,
but the wider spaced measurements I expect to be much better
then the Flex-5000.

         John you are correct that the 5000 will have
constant IMD and BDR over the entire range of spacings.
But IMD does not appear to be *significantly* different
(I define significantly as >6 dB).

Quoting Eric:

Filter            20kHz  10kHz  5kHz  2kHz
200 Hz, 5 pole    100+   100+   100+   95
250 Hz, 8 pole    100+   100+   100+   95
400 Hz, 8 pole    100+   100+   100+   95
500 Hz, 5 pole    100+   100+   100+   94
1 kHz, 8 pole     100+   100+   100    94
2.7 kHz, 5 pole   100+   98      92    n/a
2.8 kHz, 8 pole   100+   100     93    n/a

...versus 96 dB for the 5000 at all spacings.

         In my opinion, BDR is a much more significant
issue.  The 5000 will be flat at 123 dB for all
spacings versus the K3 at:

"For the particular K3 I tested the phase noise on below, I measured a
typical BDR of 140-141dB at spacings 5 kHz and wider and about 138dB at
2 kHz."  (again quoting Eric)

~20 dB difference in BDR and/or Phase Noise (from my
previous post) will be very noticeable in the following
situations:

1.  During multi-transmitter operations (multiop or SO2R
in contests, Field Day, expeditions, etc).

2.  If you have a very close neighbor (either a ham or
a powerful broadcast station).

         So I agree with your comments in general, but I
feel they apply more to BDR and Phase Noise than IMD.

                                 73,  Bill  W4ZV

P.S.  And let's all not forget that there could be some
differences in what Elecraft measures versus others!