Re: [Discuss-gnuradio] Direct ADC for Quadrature Demodulator

[Radio Dev]

Thanks a lot for Eric's comment -- "Should work fine."

I am hoping to use Joshua Lackey's Linux driver for the Datel ADC.

Now I am working on a Windows2000 with Datel's APIs for Win32.
Datel ADC can work on DMA mode and FIFO mode.
DMA -- stream continuously  (MAX 30MHz sampling rate, must use FIFO memory
when samples > 32M)
FIFO --  not continuously (MAX 40MHz sampling rate, few samples one time
depending on FIFO memory size).

Using DMA mode, the sampling rate will be 30MHz,  and seems enough fast
(>2x10.7MH).
The problem is band width.
When IF signal has a band width < 4MHz,  the sampling rate will be enough,
i.e. 30MHz > 2x(10.7+4)MHz. Dangerous but it works.
When IF signal has a band width > 5MHz,  the sampling rate will not be
enough, i.e. 30MHz < 2x(10.7+5)MHz. Can not work.

Did I have a proper right understanding?


Radio Dev

----- Original Message -----
From: "Eric Blossom" <address@hidden>
To: "Radio Dev" <address@hidden>
Cc: <address@hidden>
Sent: Saturday, March 20, 2004 2:29 AM
Subject: Re: [Discuss-gnuradio] Direct ADC for Quadrature Demodulator


> On Fri, Mar 19, 2004 at 08:38:13PM +0900, Radio Dev wrote:
> > Hello
> >
> > I want to try the Quadrature Demodulator project under wiki, using
> >
> > IF(10.7Mh) -> MSA-0886 -> RF2711 -> OPA340.
> >
> > Can anybody tell me the following project is possible ?
> >
> > IF(10.7Mh) -> high speed ADC -> software.   (just like gnu sdr)
> >
> > I have a AR5000 and a Datel's ADC with MAX 40MHz sampling rate.
> >
> > Thanks
>
> Should work fine.   Do you a linux driver for the Datel ADC?
> Will it stream continuously?
>
> Eric
>
>