Topband: SDR-1000 IMD-DR, blocking dynamic range, IP3, and IP2 measurements

[Michael Tope]

----- Original Message ----- 
From: "Robert McGwier" <rwmcgwier at gmail.com>

> 
> The big difference between this receiver and any other receiver I have 
> EVER measured is that these same numbers are true at 20 kHz,  5 kHz,  
> 1KHz, and lower.   If I can find a fault with the SDR-1000, even given 


> no axe to grind here outside of the truth.  On the Orion II,  there is 
> no way it has the same performance as the SDR-1000 inside a few kHz.  At 
> 500 Hz, even with the roofing filter kicked in,  the SDR-1000 
> significantly outdistances the Orion because of the insertion loss of 
> whatever it is Orion has done in that particular setting. > N4HY
> 

If what you say about the real close in performance is true, Bob
(and I have no reason to believe its not), I am surprised that nobody 
has tried using the SDR-1000 as the IF of a superhetrodyne receiver 
with tight filters and high intercept point mixers. Seems like that has 
the possibility of yielding a receiver that is a notch above even the 
Orion (the sub-receiver could be a standard direction conversion 
architecture like the SDR-1000 for supplying general coverage and 
the pan-adapter function). 

73, Mike W4EF...................................