AMERITEC AM-48 - Line Termination Impedances

AM-48 Test Set (18-0015) Connection & Configuration
0015-S06
6
-7
In general:
1. For 4-wire
a) Use the <SND> T and R (connecting either way) for
the Send contacts
b) Use the <RCV> T1 and R1 (connecting either way) for
the Receive contacts
2. For 2-wire, use <2W> T and R (connected either way). These
contacts are the same as <SND> for 4-wire.
6.4 600Ω/900Ω Line Termination Impedances
It is important that the line(s) be properly terminated with a matching
impedance. This paragraph gives instructions for terminating lines
with 600Ω or 900Ω impedance. To terminate lines with impedance
other than 600Ω or 900Ω connect the Ameritec Impedance Adapter
as per ¶6.5.
To terminate the line(s) correctly with 600Ω or 900Ω:
1. Choose either terminate or bridge mode:
a) Set Switch 13 to <TERM>, terminate mode, or
b) Set Switch 13 to <BRDG>, bridge mode, and terminate
the line with some other device (such as a modem) of
proper impedance.
2. Regardless of the method of termination, set Switch 11 to
<600Ω> or <900Ω> to match the impedance of the line.
Note: An incorrect Switch 11 setting results in about 1.8 dB error
in level and noise readings.