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Electronics => Repair => Topic started by: Kenny Powers on March 28, 2018, 05:14:41 pm

Title: Wavetek 4808 Unstable DC Voltage
Post by: Kenny Powers on March 28, 2018, 05:14:41 pm

Hello,

Posted this in the wrong settion earlier,

I have a 4808 which is exhibiting intermittent misbehavior details below, has anyone else come across this and found a cure? I opened the unit and its spotless inside.

For example, when set for 10VDC, it outputs 10V - but then the voltage (sometimes) slowly drift upwards
to, say, 12.6V.

When this happens:-
- the 1V and 100V ranges are seen to behave similarly
- there is no output on the lower ranges
- the 1000V range seems OK.

The problem can be resolved, at least temporarily, by cycling the power or going up and down through the ranges a couple of times.

(All other functions – ACV, Ohms etc. seem ok)

Title: Re: Wavetek 4808 Unstable DC Voltage
Post by: Samogon on March 28, 2018, 09:57:10 pm

Looks like devider board has issues. But reference is ok

Title: Re: Wavetek 4808 Unstable DC Voltage
Post by: Kenny Powers on March 29, 2018, 12:07:14 am

Any idea where this board is located or part number?

Title: Re: Wavetek 4808 Unstable DC Voltage
Post by: KhronX on March 29, 2018, 12:19:03 am

Depending on the age of the unit, there's a chance some of the electrolytic caps might've started to kick the bucket.