[hpsdr] A new entry in the direct-sampling SDR field

[Ray Anderson]

Nico-

I think you are correct regarding the IP3 spec. after re-reading the
Mercury Wiki info.

Best 73,   Ray  WB6TPU


-----Original Message-----
From: Nico Palermo [mailto:nicopal at microtelecom.it] 
Sent: Wednesday, June 20, 2007 10:06 AM
To: Ray Anderson
Cc: hpsdr at hpsdr.org; Ray Anderson
Subject: Re: [hpsdr] A new entry in the direct-sampling SDR field

> ***** High Performance Software Defined Radio Discussion List *****
>
>
> Regarding the specs, the first thing I noticed was that the IP3 number
> at 31dBm was less than stellar for a high performance receiver.
>
> Looking at the Mercury info on the Wiki it appears the anticipated IP3
> will be about 46.8dBm (if I am interpreting what it says correctly)
>
> Price is about $1072  (799 EUR)
>
> -Ray   WB6TPU
>

I agree, Ray.
31 dBm is a quasi-stellar IP3. But consider that it is the figure when
no
attenuator is inserted and the receiver's sensivity is -131 dBm.
If a 20 dB attenuator is inserted the IIP3 becomes 50 dBm and the
sensivity -111 dBm. If I am interpreting well what I've read about the
specs of the Mercury board the difference between the two receivers is
within two or three dBs.
Let me know if I'm wrong.

73 Nico Palermo iv3nwv



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