Model Z100 CW and RTTY Tuning Aid
Release Notes – Firmware Version 2.2

10 December 2007



This Release Note updates the Z100’s Assembly and Operations manual to cover Firmware release 2.2.

Release 2.2 adds a new “single tone” display mode with two options. The single tone mode allows the Z100 to act similarly to a PLL-type single tone detector. When tuned to the desired frequency, one of the green center LEDs will flash in sequence with the incoming CW. The frequency setting potentiometer adjusts the center frequency in single tone mode. Frequency memory is not operational in single tone mode.

Single tone mode is activated by selecting either position 0 or position 1 on the Z100’s Memory Address rotary switch. 

Position 0—With “option 0” selected, only one green LED operates. Until the signal is approximately correctly tuned, no LEDs will illuminate. 

Position 1—a high/low error indication is provided by illuminating one red LED to the left (low) or right (high) of center. The degree of error is not provided; just a high/low indication. When correctly tuned, one green LED operates

Under both Option 0 and 1, the “on tune” green LED bandwidth is selectable  between wide and narrow via the Z100’s 50/25 Hz slide switch. Wide is approximately 50 Hz and narrow approximately 25 Hz. Generally speaking, better noise rejection performance is observed with 50 Hz bandwidth.

With Firmware 2.2, memory positions 0 and 1 are no longer available for stored frequency settings.
The start-up sequence now blinks the current software revision number, with the major release (2) being shown left of center and the minor release number (2) shown  right of center. 


