Basics of Frequency Shifting

>Glen Herrmannsfeldt wrote:
>> Jerry Avins wrote:
>>> Glen Herrmannsfeldt wrote:
>> 
>>>> That works if the signals are the same source with different delay,
>>>> as it now sounds like you have.
>> 
>>> If the frequencies of the sources differ, how can they be the *same* 
>>> source?
>> 
>> The OP isn't giving the details, but it sounds like it might
>> be one signal with variable delay.  If the frequency of the source
>> varies with time, then delayed versions can have different frequencies
>> (at the time they arrive).
>
>He wrote that independent oscillators are in different locations. I 
>don't see how to attach more than arm-waving significance to "phase 
>comparison".

Would these arms be waving in a clock-face like manner to indicate phase?
:-\

Steve