[sdiy] Setting up PDN on Frequency Shifter

[Grant Richter]

Hey, that is really smart. Thank you for this excellent tip.

The 180 degree straight line is much easier to see precisely than telling
how round a circle is.

I don't get the shorting capacitors part though? Wouldn't you want the 90
degree PDN output to be working normally?
> 
> The old CFR Technotes suggest a technique where you use a known
> working quadrature oscillator, and you sequentially short the
> capacitors of each phase-shift RC pair. In that way, you are
> looking for a 180 degree phase shift. I could scan it, as I'm
> certain you've understood this fine explanation. ;)
> 
> sorta' like this:
> 
> 
> +-------+        
> |       | sin [ 0] --------------------------  {   0 } - | ch1/X
> | Qosc  |                                                |
> |       |            +---------+                         |   scope
> |       | cos [90] --|         |- [ 0]                   |
> +-------+            | PDN     |                         |
> |         |- [90] ------  { 180 }   | ch2/Y
> +---------+
> 
> don.
> 
> -------
> donald johnson
> dla.kwi Ensign Core
> phone: 604.222.8314
> 
>