According to my information , the reference impedance for Mexico is 900 Ohm in parallel with 1 uF. This was also used on our modemapproval (nov 96). Return loss must be > 10dB.
ref : DIARIO OFICIAL 21/12/1994 part 5.3.2 best regards Marc Decre ******************************************* * MARC DECRE * * DELTA DESIGN * * TIENSESTEENWEG 56 * * B3360 KORBEEK-LO * * BELGIUM * * * * T: + 32 (0) 16 461575 * * F: + 32 (0) 16 461595 * * Email: [email protected] * ******************************************* John Combs wrote: > > Mel, > > > Does anyone know what the Mexican reference impedance is for voiceband > applications? Is it 600 ohms? or > > some complex impedance? > > It is a complex impedance, 820 ohms in parallel with 115 nFd, then those > two components in series with 220 ohms, as shown in Figura 15. - Medicion > de la perdida de retorno, E.B. 3-15, 1994. (Note that this is almost > identical with the AUSTEL complex impedance, except that AUSTEL uses 120 nFd.) > > ________________________________________________________________ > John Combs, Senior Project Engineer, ITS/TestMark Laboratories > Email: [email protected] URL: http://www.testmark.com
