[aprssig] low power 2 meter exciter needed

Ben Jackson ben at ben.com
Tue Oct 3 13:11:58 CDT 2006

On Tue, Oct 03, 2006 at 12:16:06PM -0400, Art wrote:
> A PLL chip is ok, except that any chip I found takes a lot of support 
> circuitry (outboard divide by N counters and/or vco's), and they all 
> need a microprocessors to talk to the chip to determine it's divide by n 
> value.

I was thinking of building one around the National LMX1601.  It's a
cellphone PLL.  It is serial programmable (does require a microcontroller,
but then again something has to modulate the signal anyway!), includes
the prescalers, dual modulus counters, phase comparators and charge pump.
You still need to provide an external VCO.

In fact, you could probably drop this chip in in place of the MC145170
in the PocketTracker, although I haven't done a detailed comparison.

Ben Jackson AD7GD
<ben at ben.com>

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