Midland SYN-TECH 70-050 - Page 7

E/PROM PROGRAMMING
70-050/055
E/PROM MODULE LOCATION AND REMOVAL
The operating frequencies and optional functions for the Midland 70—
050/055 transceivers are programmed in a semiconductor-memory E/PR0M
module. To remove the module for programming, first remove the trans¬
ceiver top cover, then locate the small printed circuit board near the
front of the unit, marked "Z-273". The module is mounted on two
connectors and can be separated from the main printed circuit board by
simply pulling straight up.
PROGRAMMING PREPARATION
NOTE: The 70-050/055 contains the HD44840A22 or
HD44840A27 microcomputer (IC 9 01). The 70-1C00
programmer used to program E/PR0M modules for the
70-050/055 must be upgraded to the "E0" or later
configuration.
The 70-1000 E/PR0M Programmer Operator’s Manual contains detailed
information concerning E/PR0M module programming. Be careful to
observe the following precautions.
DO NOT APPLY OR REMOVE PROGRAMMER AC POWER WHILE THE
E/PR0M MODULE IS PLUGGED INTO THE PROGRAMMER.
IT IS NOT NECESSARY OR RECOMMENDED TO PLUG THE E/PR0M
MODULE INTO THE PROGRAMMER EXCEPT TO PERFORM BLANK
CHECK, WRITE, VERIFY OR COPY OPERATIONS.
Apply power to the 70-1000 programmer and confirm the correct display
is present.
HEADING INPUT
Input the optional heading data as described in the 70-1000 manual.
BAND SELECTION
A band selection code must be entered to program the frequency range,
IF and reference frequencies, and local oscillator injection. he
standard configuration 70-050/055 will accept only Band 50, which is
entered as BAND CODE 0. Band 50 corresponds to a 30-50MHz frequency
range, 10.7 MHz RX IF, 10.24 MHz TX IF, 5 KHz reference frequency and
high side local oscillator injection.
The 70-050/055 can be converted to accept bands 5A, 5B, 5C, 5D or 5E
as follows:
1. Band 5A, BAND CODE 0A, differs from Band 50 only in using low side
receiver local oscillator injection instead of high side. Low side
injection may be used to reduce or eliminate interferenie from
intermodulation products. Band 5A should be programmed only if the Low
Side Injection Kit 70-2175 (70-050A/055A), 70-2176 (70-050B/055B) or
70-2177 (70-050C/055C) has been installed in the radio. If a Low Side
Injection Kit has been installed. Band 50 cannot be used.
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