Jerry,

Thanks for being interested in my project.  It just so happens that the PLL
I first designed is for use in a remote controlled aircraft.  The PLL
frequency synthesizer for the spectrum analyzer is not yet *completely*
finished.  I have finished the Initial PLL which uses a MAX038CPA 20MHz
function generator and a MC145158P2 freq synth.

This PLL requires a really good power supply, as the MAX038 requires a +-5V
power supply.  The MC145158 only needs 5V, but works best with 9V.  Use the
operational amplifier of your choice, a rail-to-rail, low-noise op-amp is
reccomended.  Motorola's data sheets are invaluable for designing the PLL.

Right now the PLL will generate the "base" frequency of .1 - 20MHz.  The
resolution can be set by the PIC.  Because I can't find a TXCO (which I feel
is necessary for this application) at a reasonable price, I have obtained a
100kHz crystal to use in an external reference oscillator.

The signal can then be mixed with a signal from an XTAL oscillator that uses
several xtals.  A specific frequency xtal can be selected by the PIC
uProcessor.  This frequency is then mixed with with the PLL and then
filtered (which is also selected by the uP).

The problem with this is that after about 140MHz there are no more xtals
available.  So right now, I am spending my time trying to develop the
world's most complex xtal oscillator.

I have saved your email, and when the synthesizer is finished, I will post
it on my web page and email you the address and post it here on the PICList.

Anthony Clay
zarthrag@intcon.net