Hameg 203-6 oscilloscope
 

Hi,

I have a problem with channel 2, the calibrator 2V p-p on channel 1 is OK, on channel 2 it reads 1.8V p-p. To check the input modules I Swopped CH1 to CH2 and CH2 to CH1. I got the same readings. So conclude the input modules are OK. Checked IC701 with IC702 there are voltage differences. The Y-Gain pot VR702 is turned full on (that is zero ohms reading across it) I have the schematic for the Hameg 203-6, but there no voltages shown on the diagram. I’ve changed some of the small electrolytic caps, the voltages at the P-Test point are OK. Also swapped the IC701 with IC702, but still the same readings. Does anybody have any clues?

Many thanks.

Rob.

Re: Hameg 203-6 oscilloscope
 

There are quite a few manuals on the net. I seem to remember getting mine from the Hameg site.

Re: Hameg 203-6 oscilloscope
 

Hi,
Yes I got mine from Hameg, had a look at other models they seem to have voltages marked on them but not the 203-6.
Many thanks.
Rob

Re: Hameg 203-6 oscilloscope
 

Is the calibration source accurate ?

You could check independantly with a DC voltage source and a test meter ...

dc

Re: Hameg 203-6 oscilloscope
 

H'i (Hi,)

I think I've found the problem, on the Y-Pos II (VR705) pot it read over 700+ ohms and the value on the diagram should be 470 ohms, tested this by adding a 1.2K across VR705 to bring value down. Now it reads 2V pp. So now it's time to order a new 470 ohm pot. Thanks guys for the input.

Many thanks,
Rob