User's Manual

Exalt Installation and Management Guide
EX-i Series (TDD) Digital Microwave Radios
104 206501-019
2016-05-24
necessary. Compared to phone support from Exalt Customer Care, troubleshooting is much more
expeditious if the professional installer and/or link designer examines the system and reviews the
management information in the GUI. In turn, if the professional installer and/or link designer contacts
Exalt Customer Care, the process to rectify the system is much more expedient due to the in-depth
knowledge related to the implementation and the RF environment.
Improper RF Cable Termination
Improper RF cable termination is a very common problem. In many cases, this is a problem that occurs
during installation and is not a problem that suddenly appears. However, if cables are moved or flexed,
especially near the termination points, and radio errors, changes in RSL, or other performance issues
occur, this is a certain sign of this issue.
Another relatively easy method to test for this condition is to decrease the output power of the radio
system (at each end, one end at a time). A poor RF cable termination may be reflecting too much RF
energy back into the radio system, and reducing output power reduces the reflected energy at a faster
rate than the transmitted energy towards the far end. Be careful not to reduce the output power to the
point where the radio’s threshold is reached. Typically, a reduction of just 3 to 6dB is enough to
determine if this is the issue. If the reduction of output power clears the error condition, this is the
likely cause.
Use a reflectometer or meter that can read VSWR at the operating frequency to identify poor
terminations as well as poor antenna feeds.
Multipath Propagation
Multipath propagation is a term that encompasses changes to the RF path, such as reflections and/or
refraction, causing partial or complete destruction of the radio signal, and thus excessive bit errors and/
or system outages.
Rapid changes in temperature, inversion layers, humidity, air pressure, water evaporation, as well as
standing water or moisture on objects along the path are all examples of changes that can cause
multipath propagation. New building construction near either end of the path or along the path can
cause new reflection characteristics.
If your system has been operating without issue and is suddenly experiencing issues that are
symptomatic of a certain time of day or related to change in climatic events or some of the external
factors listed above, this is likely the cause. Consult a professional RF path engineer in these cases.
Often, minor repositioning of the antennas at either or both ends can reduce or eliminate these
problems.
RF Interference
RF interference is usually indicative of another radio system nearby either end of your radio system or
aimed towards one or both ends of your radio system – usually at or near the same frequency and
usually with a similar signal level.
Other forms of RF interference also exist, such as electronic equipment placed close to the radio
chassis or transmitters that couple onto the cabling or grounding system of the radio. Microwave ovens
and wireless communication devices used near the equipment or cabling are examples of electronic
equipment interference.
Note: The Praxsym VSWR meter is an excellent tool for this purpose.