Toughsat
Users Manual
Ground Control
- 36 -
Testing / Bypassing / Rolling Coaxial Cables
Your Toughsat system uses high-grade Belden 1694-A Shielded coaxial cables to connect the modem to the radio
equipment at the end of the support arms. These cables run from the modem to the base of the Toughsat, then internally
along the arms. Typically, the most likely place for cables to have damage is inside the unit itself. To that end, we can
test coaxial cables in a number of ways.
During these tests, you will be connecting and disconnecting cables. It is important that you do not connect or disconnect
any coaxial cables until the power to the modem and controller are off. This is to avoid doing damage to the equipment
via surge or spark.
Voltmeter Testing:
With a voltmeter or a multimeter, it is possible to test the cables for continuity. First, determine the modem output voltage
by disconnecting the cables from the back of the modem and controller, one at a time. Place one probe on the threaded
shield of the coaxial connector, and the other probe inside it. If you do not have probes narrow enough to reach inside the
connector, you may use a paperclip or other thin metal object for this purpose. Power the modem on, read the voltage,
then reconnect the coaxial cables.
Next, disconnect the cables from the base of the antenna. This time, the testing will be done with one probe touching the
center conductor and the other touching the inside of the threaded nut on the cable. Measure and record the voltage,
then replace the cables.
Finally, locate the cable connections on the radio equipment. These may be sealed with a layer of electrical tape, and an
inner layer of rubber tape. These are to protect the connectors from the damage of inclement weather, and should be
replaced as soon as the system is determined to be operational. Again, place one probe on the center conductor and the
other on the inside of the threaded nut. Measure and record the voltage, then reconnect the cables.
Ideally, the voltage from the modem should stay within 0.1vDC. If the total drop from the modem to either of the two cable
terminations is greater than 0.5vDC, this could indicate a problem with the cable(s) which might require them to be
replaced.
Bypassing Cables
To bypass a coaxial cable, you will need enough spare Belden 1694-A cable to go directly from your modem to the radio
equipment.
This is typically done when one or more cables has been determined to be “bad” and the system must be
used immediately, or before they can be replaced.
Bypassing the installed coaxial cables is as simple as disconnecting the cables (one at a time) from the modem and
controller.
Then run fresh, “known-good” cable directly to the radio equipment, disconnecting the installed cables there.
Once the replacement cable is in place, test the system again. You will want to watch carefully to make sure that the
movement of the antenna does not damage your cable, or catch on anything.
To stow a system that has one or more bypass cables installed, first stop the dish and return it to the “stow” position. This
can be done by manually adjusting the antenna using either the UCB buttons or the Manual Control Page buttons, or by
pressing the “stow” button on your controller or web interface and then stopping the antenna before it begins to lower
itself. Once the antenna is in position, disconnect the bypass cable(s) and make sure that the installed cables are out of
the way of any points of motion as well as out of the stow path of the antenna.
Rolling Cables
To “roll the cables” is to switch one for the other. In this way, a possible problem with one of the cables can be tested
without the use of a voltmeter. For instance, if your antenna was pointed and had receive lock, but you did not have
transmit lock, you could switch the receive and transmit cables. If doing so replaced your transmit problem with a receive
problem, then your receive cable is more than likely the source of the issue.
Rolling cables on a Toughsat requires that you first disconnect and switch the coaxial cables at the back of the modem
and the controller. Remember that the receive cable goes into the controller, not the modem; make sure that as you
switch them, the small “jumper” coaxial cable connecting the modem and the controller should not be adjusted.
