[TenTec] Hello Orion Users

[Jim Reid]

Carl wrote,  in part:

> The Orion DSP filters are NOT audio DSP filters.  They 
> are IF DSP filters with the 100 db of AGC action in the 
> DSP alone.  

And Bill wrote:

> DSP is done at the 14 kHz 3rd IF which is clearly audio.

Well,  let me give this a try;  sure to stimulate debate,  maybe?

Just because the final Orion IF center frequency is at
14 kHz,  does not mean your could "hear" it!!  That is,
it is not "baseband"  frequency energy.  It is still real RF energy
and has all the characteristics of electromagnetic RF
signals.

Why?

Because it has not been "detected" or otherwise converted
to "baseband".  At baseband you have DC or near DC signal
components together with audio energy which can activate 
voice coils or other transducers which will convert the
energy into "signals" perceived by human sensors:  eyes,
ears,  pressure,  taste (?).
 
Typical definitions about this issue:

baseband. A transmission medium through which signals 
are sent without frequency shifting. ... Ethernet is an example 
of a baseband network. ...also,   
baseband: 1. The original band of frequencies produced by a 
transducer, such as a microphone, telegraph key, or other 
signal-initiating device, prior to initial modulation. Note 1: 
In transmission systems, the baseband signal is usually 
used to modulate a carrier. Note 2: Demodulation re-creates 
the baseband signal.  
Note 3: Baseband describes the signal state prior to modulation, 
and following demodulation.  Note 4: Baseband frequencies 
are usually characterized by being much lower in frequency than 
the frequencies that result when the baseband signal is used 
to modulate a carrier.

That 14 kHz IF energy is still very much RF energy, that is
it is not baseband energy as defined above, and would not 
excite any sort of signal in the room air to which our ears
would respond.

You might get it to radiate as an EM wave,  if you had
an efficient antenna at that VLF RF frequency!

Not sure if this helps at all,  hi.

73,  Jim  KH7M