Make your own free website on



Windows software for Cherokee NorthStar


Frequency range from 24,255MHz to 29,365MHz
5kHz and 10kHz Frequency Step
Step Up and Step Down
Scan Up and Scan Down
Dual Watch
Repeater function (Split)
2 Memory Bank with 100 memories

System Requirements:
IBM PC compatible
Windows 16/32 bit and Windows NT operating system
1 MB of RAM, 1 MB of free disk space
EPT3600 Software
Connex CX-4400 CB-Radio

Few component`s
1 pcs. 25-Pin D-SUB Connector
1 pcs. NULL-Modem Cable

The connection to Printer port.

 25-Pin Printer Connector

Install a 25-pin D-SUB Male connector on the radio`s bottom cover, and use a NullModem cable to the computer`s printer port.
See Radio interfacing to Printer Port for more information about using PrinterPort.

Pin PrinterPort Direction Usage Connection to: Active H/L
1 Data 8 Out to radio   MC145106 pin 9 HIGH
2 Data 0 Out to radio   MC145106 pin 17 HIGH
3 Data 1 Out to radio   MC145106 pin 16 HIGH
4 Data 2 Out to radio   MC145106 pin 15 HIGH
5 Data 3 Out to radio   MC145106 pin 14 HIGH
6 Data 4 Out to radio   MC145106 pin 13 HIGH
7 Data 5 Out to radio   MC145106 pin 12 HIGH
8 Data 6 Out to radio   MC145106 pin 11 HIGH
9 Data 7 Out to radio   MC145106 pin 10 HIGH
10 ACK In from radio PTT Switch Microphone connector Pin 3 LOW
11 Busy In from radio Squelch Control Squelch sircuit, IC1 pin 8 LOW
14 Strobe Out to radio Frequency select MC145106 pin 6 10kHz = Low and
5kHz = High
18 Ground   Ground MC145106 pin 18  

Before modification After modification
MC145106  Circuit
To protect the PrinterPort:
Cut the trace between IC5 and connector to CPU-PCB....
MC145106  Circuit
and insert 9 pcs. 4,7kW resistors across the cutted traces.

Connection to the PrinterPort Squelch and PTT circuit
MC145106 Connection Circuit Connect a 4,7kW resistor to the SQ-circuit.

Use also a 1N4148 or similar diode to protect the input fron the PTT-Switch.

Connect a wire from PrinterPort pin 14 to MC145106 pin 6 to obtain 5kHz and 10kHz frequency Step.

The off-set-frequency oscillator IC10 oscillates at:
for all band.
The off-set frequency signal is obtained at IC10 Oscillator and flows into IC10 Mixer where it is beat with the VCO signal. The VCO signal is obtained from the following:
fvco = foff-set + Nfr
f vco = VCO frequency
N = programming code for divider output
fr = referency frequency step (10kHz).
When the different radio`s use different off-set X-tals, go to SETUP
and select off-set X-tal.

User Manual

EPT3600.EXE and install the file under C:\NorthStar\
Inpout16.DLL and install the file under C:\WINDOWS\SYSTEM\
VBRUN300.DLL and install the file under C:\WINDOWS\SYSTEM\

Saving files:
PC: Right-click on link and choose "Save File As"
Mac: Click and hold on link and choose "Save File As"