RF issues

The following table contains information to help you troubleshoot RF issues.

Table 1. Troubleshooting RF issues

Symptom	Possible cause	Actions
Poor RF signal.	Cable runs too long.	Ensure cable runs have not exceeded recommended lengths (400 feet for LMR240 or 200 feet for other high-quality cable). Apply a receive gain boost for extra long cable runs where signal loss is anticipated.
	Downconverters positioned incorrectly.	Check the placement of downconverters. Microwave, especially at higher frequencies, is best when the line of site to a downconverter is maintained. Coverage may not be sufficient.
	Antenna mismatch.	Verify there is no mismatch of antennas. All downconverter and transmitter antennas should match your band of operations.
	No power to BNC ports.	Downconverters require BNC power. Ensure that power is enabled on BNC ports connected to downconverters. The downconverters should have green illuminated LEDs.
	Transmitter power set too low.	Adjust the output power of the transmitter. However, if the CNR falls as you increase the power of the transmitter, more power is not the solution. CNR is dependent on frequency band. Typically, a good CNR at 1.4 GHz is 25–30 dB, at 2 GHz is 23–27 dB, and at 7 GHz is 20–25 dB.
	Transmitter settings incorrect.	Check the transmitter’s audio settings, including analog, SDI embedded, Mic/Line and phantom power.