Hameg 203-6 oscilloscope - UK Vintage Radio Repair and Restoration Discussion Forum

Trebor1220 · 6th May 2012, 1:17 pm

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.

kernowcam · 6th May 2012, 1:45 pm

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

Trebor1220 · 8th May 2012, 10:40 am

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

dave cox · 8th May 2012, 12:47 pm

Is the calibration source accurate ?

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

dc

Trebor1220 · 8th May 2012, 9:30 pm

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

6th May 2012, 1:17 pm	#1
Trebor1220 Diode Join Date: May 2012 Location: South Yorkshire Posts: 3	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.

6th May 2012, 1:45 pm	#2
kernowcam Pentode Join Date: Dec 2011 Location: Camelford, Cornwall. Posts: 116	Re: Hameg 203-6 oscilloscope There are quite a few manuals on the net. I seem to remember getting mine from the Hameg site.

8th May 2012, 10:40 am	#3
Trebor1220 Diode Join Date: May 2012 Location: South Yorkshire Posts: 3	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

8th May 2012, 12:47 pm	#4
dave cox Hexode Join Date: Jan 2009 Location: Bristol. Posts: 401	Re: Hameg 203-6 oscilloscope Is the calibration source accurate ? You could check independantly with a DC voltage source and a test meter ... dc

8th May 2012, 9:30 pm	#5
Trebor1220 Diode Join Date: May 2012 Location: South Yorkshire Posts: 3	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