Funciona perfectamente y llegó el envío en perfectas condiciones. Es el complemento ideal de todos los que tenemos un osciloscopio, para comprobar los componentes de una placa de circuitos y sus componentes electrónicos defectuosos.

I was a bit unhappy at first as I was not able to download the manual and my unit arrived with a cracked case. I began to investigate it and repair it. The instructions available on the sales page provided enough information to set the unit up and running some tests. The unit works better than I had expected. I was able to determine the frequencies used. Low = 62 Hz Med = 234 Hz Med 2 = 2 kHz and High = 14.5 kHz. The red knob selects one of 4 different internal resistances. The A/B push button turns on and off the dual channel mode so that you can easily compare one circuit board position to another. The Blue knob adjusts the position of the "B" Channel image on the scope screen. I added a power switch to the unit so that it could be left plugged in when I wanted to. I also added some English Labels and non-slip feet for the back so that it doesn't slide around on the bench. The only item I have not been able to identify is a Blue Jack on the front that is labeled "G" on the front and "T" on the internal board. If anyone has figured what the "G" Jack is please let me know. I wrote a complaint to Banggood about the inability to down load the Manual and about a week later they sent me the pdf file. Unfortunately it did not identify the "G" jack. Over All I am very pleased with the unit and the way it functions. I would recommend it to anyone who has a curiosity about curve tracers and a scope capable of X-Y operation.