From: gary@ke4zv.uucp (Gary Coffman)
Subject: Re: New licensing system? (Cut down the CW bands!!)
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Gannett Technologies Group
Date: Sat, 12 Dec 1992 17:40:03 GMT

In article <1992Dec11.205130.2075@CSD-NewsHost.Stanford.EDU> paulf@umunhum.stanford.edu (Paul Flaherty) writes:
>In article <1992Dec11.160356.23571@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>>Using phase coherent techniques, at least 12 db of additional processing
>>gain is available to the CW operator. Thus he should be able to operate
>>easily in the presence of a 10 db stronger voice signal.
>
>It's arguable that digital signal processing in the ham domain will have
>a similar effect on the hobby as did CW over spark.  In as much as these
>techniques aren't very prevalant at the moment, though, we have to deal
>with the existing equipment.  As techniques such as coherent CW become
>cheaper and more popular, it would then be more appropriate to reregulate.

The same thing could have been, and was, said in the days of spark. Tubes
were too expensive, amateurs didn't have the skill to use them, etc. But
the Feds changed the rules anyway. What I've advocated is voluntary band
plans so the Feds don't have to get involved when superior techniques
emerge the winner in the marketplace.

>>As to the interference to the voice user, I witnessed a demonstration
>>of a new DSP box at a recent hamfest. It was able to notch out several
>>CW signals, a couple of dead carriers, and a hetrodyne from a broadcast
>>station, all at once. With the unit bypassed and the tape playing, the
>>desired signal was unintelligble. With the box in circuit, *all* the
>>CW and carriers were gone with only slight clicks still present from
>>the CW operators. In addition to that, hum and the random noise floor 
>>were sharply reduced. At the flip of a switch it became a CW correlator.
>>All this in a little box the size of a Tiny 2 TNC and costing under $200. 
>>Truly amazing. Expect to see this technology built in to radios in the
>>near future.
>
>I'd be interested to see how such a filter performs on a crowded band; 
>specifically what effect it has on ultimate rejection of adjacent channels.

This particular DSP box works at audio, as do all the currently affordable
DSP boxes. While it has an adjustable brickwall filter mode, and that was 
demonstrated too, and it was highly effective, the filters in the radio would
have first crack at dealing with adjacent channels, just as they do now.

>My comment above applies to this argument as well.  Unfortunately, those
>rigs that do have this technology "built in" are already out of the price
>range of most hams.   The cheap, add on third party DSP box will probably
>be the way to go for some time now.  What we really need is a simple box,
>with a converter, a DSP chip, a little RAM, some EPROM slots, and some 
>trivial I/O (LEDs and switches) that could be sold in kit form for under
>$100 -- a cheap DSP testbed.

Well there aren't any ham rigs with this built in right now, Kenwood's
bandpass filter is not in the same league as this box, though it probably
could be with only software changes. I certainly think the $199.95 price 
point is acceptable given the capabilities of this box. Now competition 
and mass production will tend to drive the price point downward, I expect 
the component cost is under $50 today in 1,000 quanity. This is like AM and 
SSB, people complained that SSB rigs cost too much, but they bought them 
anyway because they performed so much better on a crowded band. People
won't buy equipment they don't need, well they will with the right 
marketing, but they *need* this box today, and will need it even more
if mixed mode usage becomes the norm. If solves real problems at a cost
effective price.

>Gary, you've basically justified changing the rules in the future, not at
>present.

Ah yes, spark forever. It's chicken and egg, we'll never have cost effective
equipment if it's illegal to use, and you say it'll remain illegal to use
as long as it's expensive. That argument didn't work with CW vs spark, why
should it work now?

Gary KE4ZV

Newsgroups: rec.radio.amateur.packet