1.Proposed revisions to Recommendation 0.9 (former Recommendation O.121)

     MEASURING ARRANGEMENTS TO ASSESS THE DEGREE OF IMBALANCE ABOUT EARTH

       Replace  2.5 with the following:

"2.5   Input Longitudinal Interference Loss (ILIL)

       The measurement of this parameter is applicable  to  receiving  devices
(e.g., amplifiers, level meters, etc.). ILIL is a measure (a ratio expressed in 
dB) of the sensitivity of a receiving device to longitudinal disturbances. It is 
measured as shown in Figure 5a and 5b/0.121. In principle, it is similar to the 
longitudinal conversion loss (LCL) measurement. However, since the measurement 
is performed internally (using a built-in indicating device) or at the output
of the item under test, not only the impedance balance at points a/b but also the 
effect   of   common-mode   rejection   is   measured.   (See        4.4.1    of
Recommendation G.117 [1].)"











































































       Measurements in accordance with Figure 5b/0.121  are  also  applicable  to
devices which perform a signal conversion (e.g., VF/CF side of channel translating 
equipment, A/D side of PCM multiplex equipment, etc. See  2,        point  f  of
Recommendation G.117). In this case the measurement at the output of the item under 
test requires an  appropriate  analyzer;  namely  a  selective  level  meter  for
measurements at channel translators or a digital analyzer (see Recommendation 0.133) for 
measurements at PCM multiplexers. In the equation in Figure 5b/0.121 it is assumed 
that Vo is measured at a 0 dBr point. The quantity X, is the relative level at port 
a/b.

       ii)  Replace  2.7 with the following:

2.7    Output signal balance (OSB)

       This measurement (a  ratio  expressed  in  dB)  is  applicable  to  signal
outputs. OSB is a measure of unwanted longitudinal signals at the output of a device. It 
is   measured   as   shown    in    Figure    7/0.121    (see        4.3.1    of
Recommendation G.117 [1]).  














































       The signal source G shown in Figure 7/0.121 can be internal or external to 
the device under test. OSB measurements are  also  applicable  to  devices  which
perform a signal conversion (e.g., CF/VF side of channel translating equipment. D/A 
side   of   PCM   multiplex   equipment,   etc.   See      2,   point    f    of
Recommendation G.117). In this case an appropriate external signal source, namely a signal 
generator for measurements at channel translators or a digital  signal  generator
(see Recommendation 0.133) for measurements at PCM-multiplexers is required.