Re: [Discuss-gnuradio] frontend4702 schematic and layout

[Eric Blossom]

On Mon, Feb 23, 2004 at 08:35:06PM -0800, cfk wrote:
> Dear Matt:
> 
> The only reason I put Q2/Q3 was to match your original schematic. I havent
> used the MAX518 before. The last time I did an IIC DAC I used the Philips
> PCF8591.

Q2 and Q3 were required on the previous schematic because the MAX518
output is gutless and the input impedance of the AGC controls was not
specified.  On the hand assembled 4937 boards I built, some would work
without the Q's, other would oscillate.  Hence, the Q's.

Please refer to my previous message about using an op-amp and the
aux DAC output.  I think it's a better solution.

Eric