9
QUICK CONNECT FOR THE REPEATER RECEIVER
This is a procedure that will help connect up the repeater’s receiver. It is not the only way to do it but one that we
have used that works well.
1.
You should have a repeater receiver COS and audio signal already wired to the proper connections according to
the plug layout in this manual before you start. These signals should be suitable to drive a 100K ohm load. The
input amplifier jumper JP7 setting needs to be determined. For high gain (about 10 times) do not install the
jumper. For a low gain ( about 2 times ) jumper pins 2 & 3. To de-emphasize the audio (for discriminator
audio) jump pins 1 & 2.
2.
The default trigger voltages for RX 1 and RX 2 are 2.4v off and 2.5V on. This results in a positive acting COS
These voltages can be reprogrammed if your COS signals are negative acting or need a different trigger point.
If you have a positive acting COS and 2.5v is a good trigger point then please skip to step 11.
3.
Make sure the repeater’s transmitter is disconnected or disabled
4.
Check to see what the COS on and off voltages are and write them down. The difference between them should
be 1V or so but can be somewhat less if the COS voltages are very stable. If a battery is being used the COS
voltages during battery discharge should also be taken into consideration when programming these settings.
Write down the COS off voltage and the COS on voltage on a piece of paper.
5.
Make sure the Linker IIa is in Setup mode (install the setup jumper JP4) and the following DTMF codes could
be sent from the control receiver or you can use a jumper to +12v to activate the port 1 COS input. If you use a
jumper then you would connect the 12v for ‘COS active’ and disconnect it for ‘COS not active’ when the COS
input is set to factory default voltages.
6.
You will need to enter in two voltage values that are in-between the two measured voltages in step 4. You may
use three digits and the * as a decimal point. You would enter 2.34 Volts as 2*34 on your DTMF keypad.
7.
For the repeater’s (RX 1) COS on level setting activate the function SET RX 1 COS VOLTAGE ON LEVEL.
Enter in a value that is at least 0.5v away from the measured COS off voltage. This voltage should be
in-between the measured ON and OFF receiver COS voltages.
8.
After completing the SET RX 1 COS VOLTAGE ON LEVEL function you may need to enter a second voltage
value for the COS off setting. To set the repeater’s COS off setting use the function SET RX 1 COS
VOLTAGE OFF LEVEL and enter in a value at least 0.2v away from the measured COS on voltage. This
voltage should be in-between the measured ON and OFF COS voltages.
9.
Care should be taken when adjusting the repeaters audio in level with R66 (RX 1 AUDIO) so the DTMF
decoder gets a signal which will allow a reliable decoding of any DTMF digits from the repeater’s receiver
10.
The repeater receiver COS and CTCSS input (Port 1) and the remote base / link (Port 2) COS and CTCSS
inputs are set up in the same general way and this quick connect procedure can be used to setup the remote base
/ link COS and CTCSS inputs. The Port 2 COS and CTCSS
11.
If you do not have a scope available start by sending a DTMF digit tone through the control receiver.
12.
Adjust R66 (RX1 AUDIO LEVEL) until you see the VALID DTMF LED light up. Try to find a center point so
you are not on the edge of operation.
13.
The control receiver should now be ready to perform control functions
Содержание Linker IIa
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