This document describes four methods for determining the amount of signal propagation loss caused by material characteristics of conductors and accompanying structures on printed boards (PBs). These losses result in frequency dependent attenuation@ ??@ as described in IPC-2141. Three of these methods to assess this loss are time domain based@ and one is frequency domain (FD) based. These methods are: Method A: Effective Bandwidth (EBW) method Method B: Root Impulse Energy (RIE) method Method C: Short Pulse Propagation (SPP) method Method D: Frequency Domain (FD) method Method A and B and one aspect of D reduce the attenuation to a single number. Method C and another aspect of D report the frequency attenuation versus frequency. Table 1-1 provides an overview of the four methods described in this document for determining the amount of signal propagation loss on PB conductors. EBW (Method A Description): In this method a TDR step with a specified rise time is injected into an unterminated conductor@ and the conductor's loss is determined from the degradation of the maximum slew rate of the step rise time at the open end of the interconnect. The maximum slope method described here does not use a 10 - 90% rise time measurements method. Instead@ it uses the maximum slew rate to extrapolate an effective bandwidth parameter. The via loss@ skin effect loss@ and dielectric loss all influence the rise time of the TDR step as it appears at the end of the interconnect. This method is not intended to measure absolute loss or each component of loss. Rather@ it determines a relative total loss factor called EBW that can be used to discern loss variations in transmission lines from panel to panel or lot to lot. EBW Measurement System Caveats: This method is not intended for rigorous analysis of the signal attenuation of PB interconnects but for a simple production test. Therefore@ there are several recognized limitations in the measurement methodology: a) This procedure does not deliver absolute values of loss in dB but instead delivers a parameter called EBW which is a qualitative measure of transmission line loss ??. b) There is no attempt to separate the various loss components (i.e.@ skin effect@ dielectric@ via loss@ etc.). c) There must be sufficient spectral content within the TDR step pulse for the frequency range of interest where range of interest is determined by application. d) The repeatability of the measurement is limited by the noise and jitter response from the TDR instrument.