50 Ohm output

[Flump]

Hi All

I want to try measuring ESR using my scope like Alan does here


But i dont have a proper function generator so i bought one of these
http://www.ebay.co.uk/itm/350945193079?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
but there are 2 problems i see which are it's not 50 Ohms output and the output voltage will be too high,
do i just add a VR in series of the output to drop the voltage down ?
and how to i make the output 50 Ohm ?

[michaelym]

The output does't have to be 50 ohms. As long as you have a known output impedance you are OK.

You can just measure your output impedance, it just cant be too high.

[Zero999]

A 555 timer has a fairly low output impedance. Connect a resistor, say 100R in series with the output and adjust the calculations to suit.

[Flump]

thanks very much guys will try it