[AMPS] S units

[Tom Rauch]

> >   If it was worth the effort, one of the new Analog
> Devices (AD8307; it
> >memory serves) wide range log IC's could be made into a
> truly accurate
> >S-meter circuit.
> 
> 
> Only if it's hooked in outside the AGC loop.

In my receiver that is in front of the major selectivity, and even the 
mixer.

But I believe the AD8307 could be used if "wrapped-around" the 
entire IF stages and used to supply AGC. While a large change 
like that would not lend itself to easy installation, it could be used 
in a new design with suitable loop filters to provide correct AGC 
time constants.

Seems like a lot of work compared to remarking the scale on the 
existing S meter, or simply using a reasonably good but cheap 
step attenuator.


73, Tom W8JI
w8ji@contesting.com

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