In article ,
John Smith wrote:

Hmmm, I thought it "right in line."

If such equip. was adopted, then just as with computers, you could
buy/cut/etch a "card" with the expectation it could be inserted right into
the bus of that radio and function, taking on responsibilities--for say an
audio amp (just as that EXACT capability exists with a computer bus)....

Indeed, this idea does NOT bypass homebrewers, it encourages them and
provides them MUCH more opportunity to participate in constructing their own
equip.... I see it as EMPOWERING homebrewers--far from the opposite!!!

As others have (I think) pointed out, there are some very valid
technical and regulatory problems which might make this approach less
than popular.

Here in the U.S., at least, transmitters in most of the radio services
have to be "certificated" (previously "type accepted") by their
manufacturer, demonstrating that they comply with the operational and
emissions rules for that service. In these services, almost any
physical modification of the radio will invalidate the certification,
and make it technically illegal to use it to transmit. Modifications
which don't violate the certification can only be made by technicians
or organizations with a specific license, and (I believe) may require
a significant amount of re-testing to demonstrate that the radio still
meets the requirements.

The FCC rules don't provide for the arbitrary swapping around of radio
cards in such transmitters.

Also, there's a tradeoff between modularity, and cost/performance.
The more modular a radio (or computer) is, the greater the number of
gozintas and comesoutas (i.e. signal connectors, busses, etc.). These
add cost, they decrease reliability (compared to a soldered
connection), and they limit the degree to which one can take advantage
of increasing degrees of device integration at the chip level.

The highly-modular PC infrastructure has gotten to where it is, in
terms of price and flexibility, because of the extremely large number
of units produced - there's a lot of "economy of scale". This is due
in large part to the fact that consumer, business, and industrial
applications can all use the same architectures. People have also
been extremely eager to take advantage of higher-performance
components and have been willing to accept relatively short product
lifetimes as a result... and this increases the demand for a "change
out part of the system and keep the rest" solution which demands
modularity.

I don't think that the same environment exists for radios. Commercial
and public-safety radios have a long lifetime, they have the need for
physical ruggedness which may discourage the use of a "plug-in"
architecture with lots of connectors that can shake loose, they're
rather cost-sensitive, and for regulatory reasons they probably cannot
adopt a "Users may change out components" architecture.

In these radio services, a "You buy it, and it never changes"
shrink-wrapped monolithic radio design simply makes more business and
economic sense.

Things may become a bit more friendly in this regard, at least for
base stations, with the newer "software defined radio" architectures.
However, in commercial and business services, the FCC insists that the
systems be designed and built in a way which prevents users from
making arbitrary changes to the configuration which could violate
regulations. One example of this is the Atheros 802.11a/b/c wireless
radio cards... their behavior is very strongly defined by their
firmware, and the vendor says that they *cannot* release the firmware
or low-level drivers in source-code form for fear of violating the
FCC's software-radio rules.

Frankly, I think that the amateur radio service is probably one of the
few services (and perhaps the only one) in which a general-purpose
"radio card plug-in" architecture or system could be generally useful,
and the resulting radios would probably be significantly more
expensive than monolithic-board or proprietary-bus radios of similar
capabilities.

Due to the limited size of this market (compared to business and
public safety) I doubt that you'll see the big manufacturers invest
the time and money required to develop and promote and market such an
architecture. No sense in their doing so. Without the leverage of
being able to use the same technology in other radio services, it's be
a big investment for no return.

Indeed, if some were as gifted as all that, they need only buy the case and
some foil boards/components--when they emerged from the basement--I'd expect
to see a radio of their OWN design in their hands!!!

And there, I think, you've defined the only market to which such an
architecture would be strongly attractive - hobbyists.

There might be enough of a community there to support the development
of such an architecture, just as there are communities supporting the
GNU software radio, the RockMite, and other specialized radios.

Feel free to propose a design, John Smith! If it's as overwhelmingly
good an idea as you seem to think, maybe it'll take over the world by
storm!

In short, John, I don't think it's fair to say that there has been "no
progress". Rather, I'd say that things haven't gone in the direction
you suggest, because your solution is one which solves a problem which
most people don't feel is worth solving, and comes with a cost that
most people don't care to pay.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
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