Timewave DSP-232, Operating Manual, Page: 233 / 271

Chapter 13 Troubleshooting
The DSP needs to be fed by a regulated power supply that can provide at least 12 VDC @ 1 Amp load . Many
amateurs connect all their station equipment to a single power supply and expect it to provide enough “juice” to
make their tranceiver(s) operate at full power, operate its accessories or external ones like an autotuner, SWR meter,
keyer, and the DSP-232. Alternately, you may have purchased a “power cube” that’s dedicated to your DSP and no
other device. With both arrangements, however, if the power supply is insufficient to supply all the electrical needs
of the device(s) connected to it then something has to suffer—which brings us to the DSP.
You can find out if the DSP is getting enough juice by removing its chassic cover and measuring the voltage and
current—while everything connected to its power supply is up and running at maximum current consumption—
across and through its fuse. Measure the voltage from one end of the fuse to the chassis (or other grounding point).
For the current reading, turn the DSP off, lift one end of the fuse, connect your meter’s probes in series between the
fuse holder and lifted fuse end, then turn the unit back on. If the DSP is receiving less than adequate power and
operating peculiarly, you’ll need to connect a beefier power supply to power it.
The Power Supply Cable
This is the second item you should check if your DSP doesn’t power up; it’s also the easiest subsystem component
to troubleshoot. If you used the power cable that accompanied the DSP in its shipping carton, remember that the
white stripe that runs alongside one edge of the wires is the positive (+) lead that goes from the (+) terminal on your
power supply to the center conductor of the connector that plugs into the DSP; the other conductor, of course, goes
to the (-) of the power supply and “sleeve”, or outer ring, of the DSPs power connector. If you have these connected
incorrectly or the supplied cable is polarized incorrectly, the DSP won’t work, period.
If you’re using a dedicated power cube for the DSP check it’s polarity—no manufacturer is perfect and on rare
occasion, the polarity of the wires might have been accidentally swapped. Again, use your VOM to see if this is the
case.
If you find that the polarity is correct, then tug gently at the wires at both the power supply end and connector end
while measuring voltage or continuity; Tugging can reveal if there’s an “open” in one, or both, of the conductors. If
you find an open, either repair the damaged section, replace the cable and/or the power supply.
The DSP-232
Each DSP is tested at AEA prior to shipping to make sure it operates flawlessly. Most of the time, however, troubles
with the DSP are mode specific and related to cabling, power supply and “pilot error,” rather than the hardware
itself.
For mode-specific problems, refer to the respective chart at the end of this chapter.
Cable from DSP to Computer
If you use the cable supplied with the DSP-232, you should not have a problem. If you use a different cable for
some reason, make sure the cable is not fully loaded (all pins being used). Only pins 1-3 and 5-8 are used. Refer to
Chapter 2 of this manual for an explaination of the pin assignments.
Computer/Software
If you don’t have your COM port and software set up properly for modem communication, you won’t be able to
“talk” to the DSP. Since there are literally hundreds of computer configurations, it’s up to you to make sure your
system is set up correctly for serial port communciations.
Cable From DSP to Radio
Very rarely, the wires at the connector (DSP) end of the cable aren’t seated correctly in their groves so proper
contact isn’t made; inspect the connector, and wiggle the cable leading into the connector while making a continuity
check to see if this the problem.
More likely, you might have accidentally inserted this connector so the cable faces
up rather than down as it leads
away from the DSP. The other problem, of course, is that you didn’t wire the radio end of the cable correctly for
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