[AMPS] Bird peak reading meter? Slightly off topic

[Radio WC6W]

On Tue, 12 Feb 2002 09:32:54 +0000 David Kirkby <drkirkby@ntlworld.com>
writes:

Hi everyone,
   Sorry for the tardy comment but, this reply got stuck in e-mail limbo.

> Kenneth D. Grimm, K4XL wrote:
> 
> >>I have the 43P kit, and it does indeed work about as you indicate.
> > Use an external power supply for it, though, the thing goes through
9v
> > batteries
> >>(two at a time!) like water through a sieve.

> That sounds like very poor design. The meter is only 30 uA, so even 
> to keep the meter at FSD, cells should last almost forever. The
electronics to keep 
> the peak must use very little power - a precision rectifier and storage
capacitor 
> would probably do it. Something seems amis.
> -- 
> Dr. David Kirkby PhD,

   Methinks the trouble is that the peak conversions I've seen use
standard op-amps with a couple MA of power supply current.

   I built one of those myself, in the last millennium, using a National
LMC6462, micropower CMOS dual op-amp.  It runs on 3V (single supply) and
consumes only 12uA in standby.   It will run a long time (2000 hrs.?) on
a Lithium coin cell or years on a pair of AA cells.

73 & Good afternoon,
   Marv  WC6W  










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