> Date: Tue, 12 Nov 1996 10:11:36 -0800 (PST) > From: Duane J Marcroft <[email protected]> > To: [email protected] > Subject: Austel TS 002 > Reply-to: [email protected]
> Can someone give an explanation of the note following the statement below > from Austel TS 002? > > 5.4.4 Impedance > > The impedance presented by the CE in the Hold State shall have a return loss > greater than 10 dB over the range of 300 Hz to 600Hz and 15 dB over the > range 600 Hz to 3.4 kHz against the test network shown in Figure 4. > > "Note: It is recommended that CE requiring a higher level of impedance > matching may additionally incorporate a 600 ohm network as a > switchable option" > > > I understand the first part part, but what is the meaning of the note? > Does this mean I can use a 600 ohm network instead of complex network? > Not very clear. > > Thank you in advance. > > Regards, Duane > Duane, According to CCL's Australia engineer Steve Seymour. What Austel is saying here is that the CE must meet the return loss requirement with a complex termination. However, since it is possible it may be be installed in a place where a complex termination is not actually present, they may wish to incorporate a switching option for a 600 ohm termination. This would allow a "higher level of impedance matching." but since this is just a recommended option and not the actual requirement, the equipment still must meet the return loss requirement with the complex termination. In other words, you HAVE to meet the complex termination requirement but if you'd like, you can have an 600 ohm circuit available as a switchable option that matches a 600 ohm termination. Best Regards, Joe Jackson [email protected]
