3-18 Troubleshooting
Method 1 (Using a Mule Base Station/Repeater for DC Power and Control)
This method most faithfully recreates the application, although the setup is more limited in the ability
to separate out the key-up or dekey process, and it may not be possible to troubleshoot all circuitry
as described herein. With the base station/repeater’s controlled key/dekey sequence, the PA enable
signal will be controlled by SW, and it will not be possible to measure the enabled current draws of
the PA supply lines, should that be required to debug the PA HW.
A base station/repeater may be connected to the PA, and can be used to supply DC power to the
PA, as well as control the PA through the application SW (firmware). The PA will need to be removed
from the base station/repeater, and the cover will need to be removed in order to access the circuit
boards. For this, the base station/repeater’s cable connecting the PS to PA can be used to supply
main 28.6 V and 14.2 VDC power to the PA. The 10 pin signal cable will need to be replaced with a
slightly longer cable. This is a standard 10 pin ribbon cable, and approximately 1 foot of length
should be sufficient to connect the PA to the base station/repeater. This signal cable length should
be kept as short as possible to prevent signal integrity issues.
A longer RF cable will be required to connect the Exciter module output to the PA input, and the
length will be dictated by the setup constraints. This cable should be kept as short as possible to
minimize insertion loss.
Method 2 (Using a Mule Base Station/Repeater Power Supply for DC Power with Manual
Control)
This method offers the additional flexibility that method 1 does not allow, and the PA can be placed
into an enabled state without RF output power present. This will allow for troubleshooting of
additional circuitry within the PA. The advantage of this method is that it does not require high power
lab supplies to provide the DC power required by the PA.
A base station/repeater PS may be used to provide the main DC supplies of 28.6 V and 14.2 V to
the PA. As in method 1, the base station/repeater PS to PA cable can be used. Two additional low
power voltage supply lines will be required for this method. Neither of these lines will draw
appreciable current, and supplies capable of 100 mA are sufficient.
The first of the additional supplies needed is the PA_Enable signal. This will require a 5 V level to
enable the PA, applied to pin 2 of J6000 when prompted, and 0 V on this pin to disable the PA and
put it into standby mode.
The other of the additional supplies needed is for a control voltage signal to manually adjust the gain
of the PA. Note that this supply must be capable of sinking several milliamps of current; otherwise it
will be unable to override the control loop voltage. This supply must be capable of up to 14 V
potentials.
Method 3 (Using Lab Power Supplies for DC Power and Control)
This method is essentially the same as method 2, except lab DC power supplies are also used to
supply the PA mains. These supplies will need to be capable of 15 A for the 28.6 V supply, and 5 A
for the 14.2 V supply. The PA enable and control voltage supply requirements are the same as
outlined in method 2.
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