hi there, im constructing a simple phase splitter using BC550..
as attached is the schematic..
[IMGDEAD]http://img688.imageshack.us/i/schematic.png/[/IMGDEAD][IMGDEAD]http://img688.imageshack.us/img688/617/schematic.png[/IMGDEAD]
problem is when i measure the THD for both the output, the in-phase signal turned out to be OK.. but not the inverted output.. as attached are the ARTA results for in-phase and inverted respectively..
[IMGDEAD]http://img403.imageshack.us/i/phasesplitterinphaseout.png/[/IMGDEAD][IMGDEAD]http://img403.imageshack.us/img403/5309/phasesplitterinphaseout.png[/IMGDEAD]
[IMGDEAD]http://img839.imageshack.us/i/phasesplitterinvertedou.png/[/IMGDEAD]
[IMGDEAD]http://img839.imageshack.us/img839/4305/phasesplitterinvertedou.png[/IMGDEAD]
so i thought it might be the inbalance output during measurement.. i then construct a differential circuit using INA137.. the schematic and measured THD is as attached..
[IMGDEAD]http://img23.imageshack.us/i/ina137.png/[/IMGDEAD][IMGDEAD]http://img23.imageshack.us/img23/2726/ina137.png[/IMGDEAD]
[IMGDEAD]http://img718.imageshack.us/img718/8932/phasesplitterina137diff.png[/IMGDEAD]
the low freq hum is still there.. how to get rid of it? sorry for the noobness of this question.. noob here
[IMGDEAD]http://img718.imageshack.us/i/phasesplitterina137diff.png/[/IMGDEAD]
as attached is the schematic..
[IMGDEAD]http://img688.imageshack.us/i/schematic.png/[/IMGDEAD][IMGDEAD]http://img688.imageshack.us/img688/617/schematic.png[/IMGDEAD]
problem is when i measure the THD for both the output, the in-phase signal turned out to be OK.. but not the inverted output.. as attached are the ARTA results for in-phase and inverted respectively..
[IMGDEAD]http://img403.imageshack.us/i/phasesplitterinphaseout.png/[/IMGDEAD][IMGDEAD]http://img403.imageshack.us/img403/5309/phasesplitterinphaseout.png[/IMGDEAD]
[IMGDEAD]http://img839.imageshack.us/i/phasesplitterinvertedou.png/[/IMGDEAD]
[IMGDEAD]http://img839.imageshack.us/img839/4305/phasesplitterinvertedou.png[/IMGDEAD]
so i thought it might be the inbalance output during measurement.. i then construct a differential circuit using INA137.. the schematic and measured THD is as attached..
[IMGDEAD]http://img23.imageshack.us/i/ina137.png/[/IMGDEAD][IMGDEAD]http://img23.imageshack.us/img23/2726/ina137.png[/IMGDEAD]
[IMGDEAD]http://img718.imageshack.us/img718/8932/phasesplitterina137diff.png[/IMGDEAD]
the low freq hum is still there.. how to get rid of it? sorry for the noobness of this question.. noob here

[IMGDEAD]http://img718.imageshack.us/i/phasesplitterina137diff.png/[/IMGDEAD]