The FDR measurement technique requires a swept frequency input to the transmission line.An inverse FFT (Fast Fourier Transform) is performed on the reflected signals transforming this information into the time domain.This dual role of predicting future failure conditions and isolating existing problems makes DTF an important part of service and maintenance on transmission lines.DTF displays RF return loss or VSWR data versus distance.The attenuation per foot or meter for the cable is also required in order to compensate for the attenuation versus distance.Likewise the cutoff frequency and waveguide loss are required for DTF, measurements of waveguide transmission lines.FDR is a transmission line fault isolation method which precisely identifies signal path degradation for coax and waveguide transmission lines.Although the acronyms are similar, FDR technology is different from traditional Time Domain Reflectometry (TDR) techniques.
RF failure conditions at the top of a tower or through a bulkhead frequently are not measurable with traditional tools such as TDR and spectrum analyzers with tracking generators.
Distance To Fault (DTF) is a performance verification and failure analysis tool used for antenna and transmission line service and maintenance.
It uses the Frequency Domain Reflectometry (FDR) measurement technique.
These common problems can cause unwanted signal reflections.
Poorly tightened connectors and poor environmental seals are exacerbated by acid rain corrosion.
Many components can cause problems in a communication system.