In a message dated 05/05/01, rwspahn@............. writes:

> Why not just FM it - with a voltage to frequency converter, assuming you 
> could get the resolution you are seeking. The old Qindar telemetry systems 
> worked like that and they worked well, before the days of digital. 
> A sound card can do frequency conversion. 
> Another idea, check the web for a program called "hamcom" I remember it had 
> an audio spectrum analyzer that used a zero crossing detector on the serial 
> port.  
> 

       Let me get this straight. You convert the signal to FM, you use the 
A/D to produce a digital signal, you then analyse this for frequency?? You 
guys DO like hard work! I can't see this competing with direct A/D somehow.
 
       If you convert to FM, you can programme your UART to count pulses and 
measure the frequency directly, but this requires low level programming. 
Having got the frequency, you convert to amplitude... To get 16 bit accuracy, 
you need.... And the links to hamcom don't seems to work anyway.

       Regards,

       Chris Chapman


In a message dated 05/05/01, rwspahn@............. writes:



Why no
t just FM it - with a voltage to frequency converter, assuming you 

could get the resolution you are seeking. The old Qindar telemetry systems 

worked like that and they worked well, before the days of digital. 

A sound card can do frequency conversion. 

Another idea, check the web for a program called "hamcom" I remember it had 

an audio spectrum analyzer that used a zero crossing detector on the serial 

port.  

Bob 



       Let me get this straight. You convert the signal to FM, you use the 

A/D to produce a digital signal, you then analyse this for frequency?? You 

guys DO like hard work! I can't see this competing with direct A/D somehow.

 

       If you convert to FM, you can programme your UART to count pulses and 

measure the frequency directly, but this requires low level programming. 

Having got the frequency, you convert to amplitude... To get 16 bit accuracy, 

you need.... And the links to hamcom don't seems to work anyway.



       Regards,



       Chris Chapman