[Milsurplus] A New Concept: Virtual Spectrum

[Mike Hanz]

Ray Fantini wrote:

>Perhaps the concept of Virtual Spectrum along with modes such as echolink and the like miss the entire point of radio communications. 
>When you use a external "wired " network like the internet as the mode of communications, such as voice over IP, regardless of what the end interface mimics it is not radio as amateur radio is currently understood, and at least by some backward thinking Ludities like me will not be considered amateur radio.
>

That's a perfectly valid point of view, Ray.  Just to provide an 
alternative perspective, I'm glad you defined the parameters of what you 
hold true, because it is not the *only* point of view.  I don't mean 
this to limit your thoughts or point of view, but to my way of thinking, 
Dave's idea captures the best of both worlds.  It allows us to 
experiment all we want with communications using two different 
transmission media - traditional electromagnetic propagation and 
terrestrial connectivity - without making making *any* internal 
modifications to our military/homebrew/what-have-you equipment.  If we 
want to pull the last ounce of signal out of a complex antenna array and 
call that an essential part of "radio communications", that's fine.  If 
we want to communicate halfway around the world with a microwatt set 
normally used for a twenty mile QSO, we now have that choice.  Frankly, 
I don't see a whole lot of difference between changing transmission 
media and changing transmission frequency to follow MUF, for example, as 
long as the transmitter and receiver remain the same in either case.  It 
doesn't alter the challenge of getting these old sets working in a top 
notch fashion.

But here's the beauty of it:  I have a ~140MHz split anode magnetron 
transmitter (AN/APT-4) that I would love to try out in an AM (and 
eventually a CW) mode, but it has an unusual FM component when AM 
modulated.  That element needs a lot of work before it goes "on the air" 
for everyone to hear, but I don't mind airing some dirty laundry to a 
single individual before an OO gets a crack at it on 2 meters.   I have 
a couple of 1939 vintage Navy RAT receivers that would be great for a 
QSO if they weren't so wide open - especially the 20-27MHz receiver.  
Using Dave's idea, I can use the AN/APT-4 and one of the RATs for the 
QSO...with all the yowps and yoops, key clicks, squawks, and other 
baggage reasonably well reproduced - to a completely different 
transmitter and receiver on the other end, tuned to different 
frequencies if desired.  For example, I can *finally* use the Navy MF 
GO-9 transmitter at 310kHz, and pair it with an APR-4 plug-in tuned to, 
say,  675MHz.  At long last, I can use the TU-26B MF tuner in my BC-375, 
and pair it with the BC-348 on its bottom band.  Gee whiz, I can finally 
use the MCW position on these old transmitters and tell the FCC to take 
a hike!  The possibilities are really quite numerous.

I strongly support the freedom to define what each ham wishes to call 
"amateur radio", but from what I know of it,  it doesn't seem at odds 
with what Dave is proposing.

>I will speculate that perhaps this is a proposal to produce a broad band spectrum or baseband signal and transport that via IP, in this case it can be a incredible waste of bandwidth to simulate radio phenomenon, although I will admit it will have virtually unlimited range.
>

Waste of bandwidth?  May I ask who is paying for it?  If downloading 
music files or listening to your favorite Internet radio station is 
acceptable, then I don't see this as a "waste" any more than those (and 
spam, by far the dominant component) activities, which are consuming 
*enormous* bandwidths compared to what we are talking about.  If you 
consider the spectrum requirement of the essential information transfer, 
it's all in the audio range anyway.   Since the sender and receiver are 
paying for the bandwidth through their ISP fees (unlike the radio 
spectrum), it doesn't seem like an issue subject to debate by those who 
aren't paying for it, IMO.

>The relevance of this statement in this forum is that as chousing to operate vintage military equipment as apposed to "modern " off the shelf items I view this endeavor as a challenge, when everything is working correctly and on the rare occasion when I get it all right it all works and I can talk with another person over the air , directly, without the aid of a third party network.
>

You are preaching to the choir there, but without having had an 
opportunity to run through the concept, I'm a little puzzled by the 
conclusion.  Dave's proposal doesn't diminish our choices to pursue what 
you espoused in any way.  See the examples I mentioned above, which 
permit a much wider variety of combinations than we have ever had 
before.  If one doesn't wish to operate their vintage equipment into a 
dummy load as opposed to an antenna to achieve the same ends as using an 
antenna for the final link, that's their prerogative, and I certainly 
support that.  In the end, it's all about choice.

>Please do not think that I oppose Mr Stinsons work, It has many valid points, but the future of amateur radio is not the internet, and if we make it the internet we may as well all turn our licences in now.
>

A laudable assertion of personal opinion, which is everyones' right to 
make - but I think this proposal opens up quite an interesting set of 
possibilities that many of us will enjoy for years to come.  It affects 
neither the transmitters nor receivers we use today, and simply replaces 
the antenna portion of the communications system.  If we think of our 
endeavors from a systems standpoint, then it becomes an engineering 
alternative to pursue in parallel with the traditional antenna farm.  I 
have always believed that choices are a *good* thing!

Best 73,
Mike Hanz  KC4TOS