[GreenKeys] SELCAL today

[Bob Camp]

Hi,

I agree with you that a DSP based modem/TU can with enough effort 
handle just about any scheme we can imagine. The issue is being 
compatible with a whole bunch of existing equipment.

If we go with a fancy system there are various phase shift key systems 
that run rings around good old straight shift FSK. For that matter 
multi tone FSK will run circles around straight shift.

I have no problem at all with neat technology. It's what pays the bills 
around here. I just think we are headed off in another direction with 
this net. More or less I would say we are trying to put as much into it 
as we can without eliminating a 1960's technology solution on the 
receive end. I wouldn't say that the 1960's solution has to be 100% 
full feature, just that it is compatible enough to operate on the net.

	Take Care!

		Bob Camp
		KB8TQ

	
On Apr 27, 2004, at 10:00 PM, Stan Wilson wrote:

> A lot has happen in the past 45 years and it is now possible to do many
> things that were not even thought of as science fiction in the mid 60s.
> Yes, it is possible to inter-mix 60 wpm and 100 wpm machines.    I
> prefer the 60 wpm speed and 170 hz shift, but a smart modern electronic
> stunt box can handle this problem, it is a piece of cake.  Remember the
> stunt box is not a TU, the TU worries about the shift and speed, but a
> modern stunt box could sort it all out.   TU are cheap now days, many
> free for the asking so it is possible to have both 170 hz shift and 425
> or 850 both decoding the RF channel at the same time.  I bet over half
> the people on this list has more than one working TU.
>
>
>
> Modern circuitry has got to the point that if you can imagine something
> in your mind, it is possible to design the circuit.   We are no longer
> restricted by dual FF in a package or four NAND gates to a IC, we now
> have million gate devices just waiting to be configured and programmed.
> Not only that; these devices are super fast, often running at 300 mhz
> internally and processing everything in parallel.   Cost well under $50
> each.
>
>
>
> Sure we still have RF communication multi-path problems, noise,
> interference etc. but once those signals pulses are converted to 
> digital
> it's baby bar the door.
>
>
>
> And even some multi-path problems can be helped with DSP and 
> algorithms.
>
>
>
> Thanks to the many messages on the list I just about have a design
> specification work out - Remember, have to see it work in your mind
> before it can be designed.  I will try and get it cleaned up and posted
> in about week.
>
>
>
> I think we might have an FCC problem, since we can not run beacons on
> the lower HF bands.   A good WRU/SELCAL system might fall under beacon
> rules, Ug...  I think.   Our modern laws can not keep up with the
> technology.
>
>
>
> Stan AK0B
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> --- StripMime Report -- processed MIME parts ---
> multipart/alternative
>   text/plain (text body -- kept)
>   text/html
> The reason this message is shown is because the post was in HTML
> or had an attachment.  Attachments are not allowed.  To learn how
> to post in Plain-Text go to: http://www.expita.com/nomime.html  ---
> _______________________________________________
> GreenKeys mailing list
> GreenKeys@mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/greenkeys
>