KA7EXM DSP-10 Info/Exchange
Udiag3, another PLL Tuning Program

This page describes a program written to sweep the 126 MHz PLL across its entire tuning range.  With this program, you should be able to verify PLL lock across the entire band.

The Program:

The program is quite simple actually.  With some help from Bob, I computed the PLL values to set the frequency for 122.0 to 128.4 MHz in 0.2 MHz steps.  There is a 5 second delay between each step, and the loop repeats forever.  Similar to UDIAG2, the FL1 LED will turn OFF when lock on both the 19.68 MHz and 126 MHz PLLs have lock.   Note a slight blip (100mS) on the LED will occur to tell you a step has occurred.

The Procedure:


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