[Amps] PEP Wattmeters

[David Cutter]

Larry

The TS922 will drive capacitive loads and there are other modern op amps 
also.  There is a LT product I cannot quite remember (let me get back to the 
office on Monday) that is also very low power <100uA, so it is good for 
battery use.

I don't think in a ham shack you need worry much about temperature drift 
with these modern op amps either.

David
G3UNA

. However OP amps typically don't
> like to drive a capacitive load. If you make the cap small, you need to
> make the resistor large and long time constants will be limited by the
> leakage of the components and circuit board. Large caps will also limit
> the fast pulse capture due to finite output impedance of the op amp and
> diode as well as the slew rate of the OP amp. Details Details Details
>
> None of the circuits I've seen so far have any offset drift
> compensation. Is this not needed? Or, is it just ignored like so many
> other details.
>