[hpsdr] Dynamic range.

[Bob McGwier]

These are almost in 100% in agreement with my calculated values (+/- 1 
dB). -14 dBm (calculated -15 dBm) should block and I calculate the 
dynamic range to be 105 dB and agree with your MDS. It should be 
impressive to anyone. That level of dynamic range is quite hard to 
measure accurately so let's say that is "more than enough". It would be 
my suggestion for those wishing to use this on low bands to raise the 
overload by using filters and attenuation to bring the MDS up to the 
level of the atmospheric noise floor. On a crowded 160m band (say during 
a contest) MONSTROUS signals here on the east coast of the U.S. and in 
Europe on broadcast bands are important enough to not waste sensitivity 
that you cannot use.

Thanks to Phil's, Bill, Lyle, and TAPR and others for this great work.

Bob
N4HY


FRANCIS CARCIA wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
>   
>
> ------------------------------------------------------------------------
>
> Hi All.
> I finally got a chance to check the dynamic range with the latest 
> software on 75 meters. I started with two signals spaced 2.5 KHz apart 
> and worked out to 50 KHz spacing. The spur made audio with both 
> signals around -26 dBM. So with an MDS around -136 dBM at 500 Hz. 
> bandwidth we are looking at a dynamic range of 110 dB. Blocking 
> happens when listening to one signal at MDS and the other at around 
> -14 dBM.
> I'm impressed.
> Above tests with no attenuator switched in. I have not replaced the 
> relay yet.
> Frank WA1GFZ
>
> ------------------------------------------------------------------------
>
> _______________________________________________
>   


-- 
ARRL SDR Working Group Chair
Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats,
NJQRP, QRP ARCI, QCWA, FRC.
“Order and simplification are the first steps
toward the mastery of a subject.”, Mann


 1232332646.0