NOW, this is getting quite interesting. I was not aware of what George was
explaining, but it was quite enlightning. By golly, I'm starting to learn
something from "THE GREAT TENTEC-ORION MARATHON DISCUSSION". Pretty cool info!
73/Tim Logan KB7OEX
Quoting "George, W5YR" <w5yr@att.net>:
> Well, let's look at the other side of the story:
>
> If a system can be updated or re-defined by a single ROM flashing,
> then
> this suggests strongly that the system is fairly unsophisticated in that
> it
> can function from the contents of a single ROM. Small systems like the
> Pegasus and Jupiter and even the Kachina use only a single
> micro-processor
> that works from a single ROM and thus it is feasible to make such
> changes
> as are possible with firmware updates, etc.
>
> Why isn't the PRO updatable the same way? Mainly because it is a much
> more
> complex system containing not only a dedicated DSP processor chipset
> but
> also some 5 or 6 other uprocessors in various parts of the radio, and
> each
> of them has burned-in ROM instructions. If all of these processors
> were
> operated in a distributed network, not only would the system
> complexity
> greatly increase - along with the cost - but operating speed could
> become
> compromised unless some pretty fast busses and memory devices were
> used.
> Distributed computing is nothing new, and networks are old hat, but how
> to
> use these in a complex radio system and still control costs and
> provide
> real-time performance can be a major design problem. And solving those
> costs moeny - big time!
>
> Personally, I am very pleased that my PRO cannot be "upgraded" with a
> PC
> card change or the like. My Kachina could be - and yet the PRO runs
> rings
> around the Kachina due no doubt in part to its use of multiple
> dedicated
> processors not necessarily operated in a distributed network with the
> overhead and expense that implies.
>
> I think that this whole idea of "software-defined" radios has gotten
> way
> out of hand and divorced from reality. The fact that a radio may be
> largely
> *controlled* by software does not equate to its being a
> *software-defined*
> radio. In order to remain current and to add many types of new features
> and
> capabilities, at least some of the existing hardware must be replaced,
> either by modification or substitution. This calls for a modular
> construction which can be much more expensive than more conventional
> layouts. For an example, compare the extensively shielded modules used
> with
> the complex backplane structure of the Kachina 505 DSP with the
> implementation of the Pegasus. Yet, when a fairly minor change was made
> in
> the Kachina to upgrade the Speech Monitor among other things, one was
> required to purchase a new $400 module and firmware and a new software
> control program to enjoy those advantages. Then they stopped making HF
> radios . . .
>
> When our radios consist of high-speed ADC/DACs hanging off the antenna
> terminals with ALL signal processing functions done in software, then
> perhaps we can talk about software-defined radios. Until then, a
> practical
> amateur transceiver must comprise a good deal of discrete hardware and
> circuits which software perhaps can switch in and out or change
> settings,
> etc., but as long as we are blessed with this hybrid world of software
> and
> supporting hardware, let's be honest and call them
> "software-controlled"
> radios, which they truly are. But software configurable? We are
> getting
> closer and closer every year - witness the huge growth in the use of
> menus
> for defining radio parameters and operating conditions - but we aren't
> yet
> to the point where marketing can claim that their product is truly a
> software-defined radio.
>
> Tim and I are in full agreement on one thing, though: those @#$%^
> green
> legends on the PRO numeric pad keys! The penalty of "doing black" and
> not
> being tacky with contrasting lettering is the hard-to-read panels we
> have
> on so many radios today.
>
> 73/72/oo, George W5YR - the Yellow Rose of Texas
> Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
> Amateur Radio W5YR, in the 56th year and it just keeps getting better!
> QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
> Icom IC-756PRO #02121 Kachina 505 DSP #91900556 Icom IC-765 #02437
>
> All outgoing email virus-checked by Norton Anti-Virus 2002
>
> cyr999@extremezone.com wrote:
> >
> > Hi folks -
> >
> > One thing that I think TenTec is REALLY smart about is the flash rom.
> My 756PRO
> > cannot be updated by flash rom. Instead, you get stuck with having to
> buy the
> > "next generation 756" and your current generation suddenly drops in
> market
> > value. That's good if you buy the one that dropped, but rotten if you
> want the
> > latest changes. Icom's practice of doing this is my biggest objection
> to Icom.
> > With TenTec's approach you feel like the rig could be current for a
> good number
> > of years.
> >
> > In another vein, as many of you have mentioned, the OMNI's are TOTALLY
> user
> > friendly and the face plates are very easy to read. However, the ICOM
> 756 is a
> > no brainer to operate and very intuitive (thus pretty competitive in
> that
> > area)....you don't really need the manual. On the other hand it's A
> REAL PAIN to
> > read sum of the "green on black" numbers - too small and poor color
> choice. I'm
> > amazed that they cannot make an easy to read radio face!
> >
> > Just a few more thoughts. 73/Tim Logan KB7OEX
>
|