Re: [Discuss-gnuradio] radio front end ?

[Eric Blossom]

On Thu, Mar 14, 2002 at 11:28:23PM -0800, Steve Schear wrote:
> 
> >I looked thru to message archive and found this
> >"FYI, it's a Microtune 4937DI5 3x7702 module.  Tunes from 50M to 860M..."
> >
> >I checked their web site and didn't find that specific model number listed.
> >What looked close was http://www.microtune.com/products/49xx_Series.html
> 
> You'll need to sign up to access their detailed technical data.  I had to 
> dig around a bit with the salesman to find this board. The more popular 
> 3x8899 (43.75 MHz IF) is what's usually vended.  They are both models in 
> Microtune's 4937 DI5 RF Tuner Module series.  The eval board is part number 
> 49X7.

We're really happy with the module, but the eval board itself could
use some help.  If you have the wherewithal to design and get pc
boards built, I've got a couple of suggestions, and would be willing
to draw up a schematic for you. 

The existing eval board requires +5, -5 and external inputs for the RF
and IF AGC controls (typically 1 to 4 volts).  I'd like to put a small
switcher on board the new eval board to handle the power, a dual trim
dac for the AGC controls that we can drive using the I2C bus that is
bit banged over the parallel port.  Also, I'd pick a different choice
of pins on the parallel port, because as is, it takes a bit of hair to
control the board from linux.  Reassigning some of the pins would make
this much easier.

Eric