[Milsurplus] [Boatanchors] OT: (Computer) Smart People: Audio Streaming

[David Stinson]

Re: Streaming 22K Audio real-Time

Thanks to those who've replied.  Here's the idea:

Before I get started- this is not suitable for
high precision, small signal modes like WSPR etc.
There are tons of people doing that already and
Lord bless them; they don't need any help from me.
I'm interested in plain-old CW and 'Phone.
Don't need 1 Hz freq stability for that.

The idea is a "remote front end"
( not not *NOT* a remote-tuned receiver you work
with your computer like SDR etc.) so that a small
band of frequencies can be streamed in 
near-real-time from a quiet, remote location 
to your desktop. I know you can do that with an
SDR.
The front-end itself is not my issue. 
I want to stream a small band of frequencies 
with little or no lag and use them to modulate
a "baseband" to be used by my BA receivers.

How many of you are familiar with the old analog
microwave concept of a "baseband?"

I want to mix a 470KC Local Oscillator in 
a broad-band mixer- flat from 0-11 KC,
 with received signals on the 630 meter band 
at a quiet location and feed its output into 
a computer sound card input.
With the sound card "recording" at a 22KC rate, 
the bandwidth of the streamed audio will be
0-11KC,
corresponding to 470-481KC.  

For instance:
If we have signals on, say, 472.5, 473, and 477KC,
the (low-passed) mixing products will be 
2.5, 3 and 7 KC (discounting the noise floor
products).
These low freqs are digitized by the sound card,
streamed to the user and either demodulated at 
the computer or- if feed to an identical 470 KC LO
mixer, feed directly into your receiver's antenna 
jack so you are, effectively, using your receiver
with an antenna lead-in all the way to the remote
front-end's location.  The stream replaces the 
antenna and feedline.

I did this several years ago on 40 and 80 meters 
and it worked well except for lag, 
which piled-up until there was minutes of delay.
Not good if someone is trying a QSO.  

I wanted to listen to a few KC of 40 meters while
working in a microwave/Data station, but the RF
noise
floor was like 30-over-9.   
I used a remote mixer at my home, piped the output
to a common consumer audio streaming service to 
stream that baseband, then feed that into an
 identical mixer at the microwave station.  Could
listen to the 40-meter net with my Drake receiver
 just fine save for the lag.
 
That was 8 or 10 years ago and I'm hoping better 
streaming solutions have come along since then.
I could reduce the A/D rate down to 8 KC
and still capture from, say, 471 to 475 KC (471 
because the LO is at 470 and the first KC is
eaten by the LO noise).

The point is to listen with my BA gear- not a
laptop.
Was able to "transmit" to the remote end as
well.  You could have a perfectly legal and "real"
spark QSO using a couple of these if the lag can
be beaten.  The stream replaces the antenna and
the
"ether," but the signals are real.

So that's the idea.  Surely SOMEONE has come-up
with a "transparent" end-to-end audio channel
with room for an 8, 11 or 22 stream 
without all the lag?

TNX ES 73 DE Dave AB5S