LF: Calibrating LF Current Meters

["g6tmk" <g6tmk@thersgb.net>]

Hi All,
I built the little antenna current meter shown in the LF Experimenters
Handbook last night (Page 81).
And it works. I measured the current from my HF rig into a dummy load at
1.8MHz, and it gave sensible results ...
But how can I calibrate it - how do I know that an indicated Amp really is
an Amp.
My DVMs, being intended for mains current measurement, don't have the
frequency response.
How have other people done it ?  Any ideas ?
73
Hugh M0WYE