[Lowfer] WSPR Weak Sig vs. QRP

[Eric NO3M]

Regarding receiver specs, a few examples for Third-order dynamic range 
of some receivers cited by LF/MF ops and a couple additional for comparison:

R-75 67 dB @ 5 KHz
TR-4C 68 dB @ 2 KHz
JRC-525 72 dB @ 5KHz
IC-706MK2G 74 db @ 2 KHz
Collins R-390A 79 dB @ 2 KHz
Elecraft K2 80 dB @ 2 KHz
Flex1500 88 dB @ 2 KHz
Flex3000 90 dB @ 2 KHz
Elecraft K3 95 dB @ 2KHz
Flex 5000 96 dB @ 2 KHz
Perseus 99 dB @ 2 KHz
Elecraft KX3 104 dB @ 2 KHz (w/ roofing filter)

While the R-75 may have good "sensitivity" at LF/MF, it is rather poor 
for in-band strong signal handling, on par with a Drake TR-4C (my first 
HF rig).

Full list: http://www.sherweng.com/table.html

And of course, upconverter quality will effect the performance of those 
rigs that need one.

73 - Eric NO3M, WG2XJM