[hpsdr] Janus frequency response ?

[Richard Stasiak]

Good work Al, thanks for the information.

Now, my next project is to bypass the SDR1000 op amps and get rid of  
the hump.

Rick ve3mm

On 6-Jun-07, at 6:45 PM, Al wrote:

> ***** High Performance Software Defined Radio Discussion List *****
>
> FWIW ...
>
> Okay. After setting jumpers R2 & R17 on the Janus board  Here are some
> new numbers... ( Un jumpered  included for comparison )
>
>
> I feed an HP-204C audio gen directly into the Janus I/Q input  
> connector
> Input).  I with 145mv from the sig gen, I read the following levels as
> reported at the bottom right of the Power SDR (1.6.3) pan adapter  
> screen...
>                                          R2 & R17 Shorted
>              R2& 17 open       Before       After
>                             Ref        Recal
> Recalibration                Ref
> Freq.      I&Q       1Khz      I&Q        I         Q           
> I&Q      1Khz
>               (dbm)
> 1Khz     -52.0        0db      -38.3       -66.4  -66.5      
> -64.0       0db
> 5Khz     -53.0       -1          -38.5       -66.5  -66.6      
> -63.9     +0.1
> 10Khz   -53.0       -2          -38.4       -66.4  -66.5      
> -64.0       0
> 20Khz    -54.8      -2.8       -38.5       -66.9  -66.6      
> -64.3      -0.3
> 40Khz    -58.5      -6.5       -38.9       -66.7  -66.6      
> -64.5      -0.5
> 80Khz    -64.0      -8.0       -41.0       -66.9  -66.7      
> -65.6      -1.4
>
> The levels displayed within the pan adapter display where slightly
> different above the DDS Freq compared to below the DDS frequency.  The
> numbers reported above are the greater of the two responses.
>
> AL, K0VM
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