Re: [Discuss-gnuradio] AOR 5000 as front end to USRP

[Matt Ettus]

Eric A. Cottrell wrote:
> Hello,
>
> Does anyone use a AOR 5000 as a front end for the USRP?  The docs for
> the USRP say that it is not very sensitive but I thought the IF Output
> from a AOR 5000 could drive it.  It seems to work for strong signals but
> I am getting the impression that a 10 dB or so amplifier would improve
> the situation.

Did you turn up the RX PGA gain?  You can get an additional 20dB there. 
Also, the BasicRX and LFRX inputs are 50 Ohms.  Can the AOR drive that?

>   Is there a difference between the Basic Rx and the LFRX
> board? 

The BasicRX sends the input through a transformer and into the ADC.  The
LFRX sends it through a unity gain amplifier first.   For 10.7 MHz there
should be no difference.

>  I have the LFRX board.  Is it better to drive the LFRX single
> ended into one input or differential with the A and B inputs?
>   


The A and B and independent inputs.  you can use them as separate
signals or as I and Q for the same signal.  They are not differential
inputs.  They are single ended.

Matt