[aprssig] Waveform (signal) on MX614 RXIN pin?

[Ron Tonneson]

Jim,

Take a look at the block diagram on page 3 of <http://atic.phys.lsu.edu/aces/Docs/Component%20Docs/mx614.pdf>.  Pin 5 is 
the inverting input of an op-amp, pin 6 is it's output.  That is the reason why I see very little voltage on pin 5.

Yes, the signal on pin 6 is out of phase with the input due to the input being on the inverting input of the op-amp.

Ron - K0QVF

James Washer wrote:
> One last question... do you have a dual trace scope? If so, are the signals on pins 5 and 6 out of phase by 180degrees? My belief is that the chip is (attempting to) scale the signal on pin 6 by feeding back a signal 180 out of phase. The resistor between 5/6 sets the bias, the cap controls the amplitude.. but I want to make sure this is the case.
> 
> thanks
> 
>  - jim 
> 
> On Sun, 01 Jan 2006 07:24:19 -0600
> Ron Tonneson <ronton at southslope.net> wrote: