Rev B
31
APPENDIX C: PROM Installation and Initialization
The instructions described below are for reference purposes only and are not intended as a
general recommendation or endorsement by the manufacturer for independent firmware
installation by the user. To avoid the potential for degrading receiver performance or of
inadvertent receiver damage, it is recommended that any firmware installation be performed by
the manufacturer
1.
Remove the two Phillips screws located at the rear of the receiver which secure the bottom
panel then remove the bottom panel.
2.
Remove the 14 Phillips screws which secure the cover of the shield box then remove the
cover.
3.
Carefully remove the PROM from the socket located near the left centre of the shield box (see
the figure on page 33). Use a PROM puller if available however two small screwdrivers can
be used to gently pry the PROM from the socket.
4.
Gently seat the new PROM making sure that the legs are all aligned with the holes in the
socket then press the PROM home.
5.
Turn the receiver on.
6.
If the new PROM is sufficiently different from the old one, the receiver will sense the change
and automatically start the ‘new PROM’ routine. If the receiver does not run the ‘new
PROM’ routine you must initiate it manually by pressing ‘SHIFT’ then ‘F1’ on the keypad. A
message asking if you want to start the ‘new PROM’ routine will be displayed. Answer yes
then enter the access code (40697).
NOTE: in some software versions step 12 (Set Decode Threshold) will be performed first,
followed by step 7
7.
The message ‘Initialize tables and storage?’ will be displayed. Answer yes.
8.
The message ‘Program frequency range?’ will be displayed. Answer yes.
9.
When the ‘Enter start frequency’ message is displayed enter the base frequency of your
receiver in MHz. The start frequency may be found on the label located on the battery
bracket inside the receiver (see figure page 33). For example, if your receiver is set up to
cover the band 148 to 152 MHz the number ‘148’ would be entered. You may include up to 3
significant decimal places after pressing the ‘.’ key. In the event that the frequency entered is
incorrect the ‘DOWN-ARROW’ key may be used as a delete and backspace to correct the
entry. When the frequency entered is correct use the ‘UP-ARROW’ key to confirm the entry.
10.
At the ‘Enter LO frequency’ prompt, the local oscillator frequency of your receiver must be
entered. The LO frequency is found on the same label as the start frequency (see figure page
33).
11.
Note: before performing this step be prepared to verify the synthesizer count value
*
with the
factory value when it is displayed.
At the ‘Enter IF frequency’ prompt the IF frequency of your receiver must be entered. The IF
frequency and synthesizer count value are found on the same label as the LO frequency (the
IF is normally 10.7). After the IF frequency has been entered the following information will
briefly appear on the display: programmed frequency range, synthesizer count value and
default COM port settings. It is critical that the synthesizer count value displayed matches the
