From: Paul Keinanen on Sun,May 8 2005 11:54 pm

On Sun, 08 May 2005 10:44:27 -0700, Tim Wescott
wrote:

The basic difference is that with a digital system you either end up
with a clean signal or a useless signal. In an analog system the
character and purity of the signal must be carefully guarded, at
least
until you manage to digitize it. This means that there will be a
much
greater chance that adding a new card to the radio will degrade not
only
the function of the new card, but the function of all the other
cards.

Second, the PC market is a huge one, with great advantages to be
derived
from common equipment and software, and much smaller advantages to be

derived from commonality. This is the exact obverse of the radio
market, including homebrew radios. To make a "card" radio would be
to
define a basic radio architecture, probably down to the IF frequency
(or
at least to the point of forcing you to match your IF and front end).

While improvements could be made within this structure an independent

experimenter couldn't play around with such things as
direct-conversion,
different IF schemes, etc., without extensive modification.

I agree that it would be quite hard to make a good quality radio with
some common backplane structure. However, connecting various
functional modules with 50 ohm input and output impedance could be
used to make quite different radios with good specifications.

That's already been done in the RF industry for a half
century.

As one example, take the U.S.' AN/PRC-8, -9, -10 series
of manpack transceivers covering high-HF into low-VHF.
Still in the vacuum tube era, all of the IF modules
included the IF tuned circuits as well as the subminiature
tube. If the tube filament burned out, the entire module
was replaced. NO alignment tweaking was required. Design
was done back around 1950.

As for standards on control...start with the ATLAS (for
USAF test equipment) and continue on to the IEEE-488
interface. Those standards worked with "modular"
components capable of testing receiver sensitivity down
to noise level with KNOWN signal levels. By the way,
test equipment for RF has been standardized at 50 Ohms
since WW2 days.

For
instance Mini-Circuits also makes various diode ring mixers,
amplifiers and apparently also VCOs that are boxed and have BNC or SMA
connectors. With each functional module in a metallic enclosure,
controlling the spurious radiation between modules is much easier. I
don't know that anyone would make filter modules, which would be
required to build a complete radio. Also SSB-Electronics sold separate
amplifier, mixer, frequency multiplier and crystal oscillator modules
mainly intended for a 10 GHz transverter.

Unfortunately the cost of these modules is quite high, apparently due
to low production volumes and large amount of manual labour needed to
assemble them. If there would be a large demand for such modules, it
would make sense to design them to require less manual labour to
assemble them and hence get the price to more affordable levels.

Define "more affordable." :-)

"Filter modules" have and are built to order by dozens
(if not hundreds worldwide) of companies. The costs
ARE high because they are built TO specifications and
such have to be TESTED to meet those specifications.
Is there comparable KNOWN/calibrated test equipment
in the average homebrewer's hobby workshop that is
comparable...even at "low" frequencies of HF? Actually,
Kaylie's Mini-circuits DOES use calibrated, automatic
test equipment to check out each module, small
quantities to large quantities. Mini-Circuits doesn't
have the market demand to do production runs in the
10,000-lot quantities.

The mystique on L-C filters is largely that...mystique.
Without some good, calibrated test equipment, it is
very difficult to determine what a "filter module"
has for performance. Synthesis (design) of the values
for a particular filter type was arduous until folks
came out with computer-aided design. I have a working
freeware program for PCs on that...send a message in
private e-mail if you want one transmitted to you.

As to cost, just look at a cellular telephone handset.
Those can cost around US$ 50 each, new. They work in
a band roughly centered at 1.0 GHz. Microwaves.
Complete microwave Rx-Tx with synthesized tuning.
For half a hundred US dollars here. A mere 30 years
ago that would be almost inconceivable. Three years
ago the U.S. Census Bureau said that one in three
Americans have a cell phone subscription. That's
roughly 100 MILLION units either out there or waiting
to be used. Market quantity and competition in that
market are the key to bringing down costs. Radio
hobbyists just cannot possibly get close to such
market quantities.

While a backplane would not be suitable for running the RF signals, it
would be a good idea to have a common control interface standard. This
might be some sort of serial interface or perhaps a CANbus interface
as used on some AMSAT satellites.

Who says a "backplane would not be suitable?" :-)
Those PC backplanes carry terribly broad spectra of
RF...from (literally) DC on up to the low microwaves.
No "perhaps" about it. Thing is, the layout can NOT
be done as if it were wire-wrap; i.e., in random
order of wire placement. With broadbanding anything,
every single adjacent trace becomes a COUPLER and
unwitting layouts can produce remarkable crosstalk
effects. Designers have known that for decades and
handle it...all kinds of Application Notes and info
out in public access available for anyone...just too
specialized for the "weekender" small-project
assembler hobbyist.

The IEEE-488 is a mature standard for control and
interface for computer-controlled, interconnected
systems. Would be a bit TOO all-inclusive for a
special-purpose new design. The "interface" does
NOT have to be some kind of "new" thing used on the
latest whatever out in space. It's just a control-
and-response avenue carrying signals of a standardized
kind...a few wires/traces perhaps...laid out properly
if required to be broadbanded or broad in dynamic
signal range. Not a big thing, but needs some
THOUGHT before becoming hardware.

John Smith wrote:
gb:

Well, we certainly need to examine the "bottle neck" and remove it... before
we are doomed...

If we can't institute this "radical" idea here, we need to look at Canada,
Mexico, So. America, China, India, etc...

When there are as many functional radios (or "cards") hitting the dumpster
as there are functional computers and related equip. (replaced with
upgrades) we will know the right idea has prevailed and radio has come
home...

I hope you are kidding, John. That is the absolutely worst part of the
PC paradigm. Thousands of perfectly good electronics thrown out, often
made obsolete due to software that is bloated and poorly written (mostly
OS software. At least old radios are still useable

I would think there must be some EXCELLENT argument/reasoning serving as a
road block, or else, others are simply going to pass us by...

The PC paradigm is a poor one, and not to be emulated. PC's will
finally be mature when we don't have to replace them on almost a yearly
basis. At that point, software writers will be able to write good software.

- Mike KB3EIA -

To make a positive posting about why the "board" receiver doesn't exist.
.. . First, I consider my PC. While my very first PC had a bunch of
cards, my current one has none except the RAM. The video adapter,
Ethernet capability, sound system, modem, serial, parallel, and USB
ports are all on a single board, built in.

Why? Simple -- it's cheaper.

I worked at Tektronix for many years. During that time, Tek made both
portable scopes and laboratory scopes, the latter having a mainframe and
plug in modules. For a given configuration with the same features, the
lab scope was always considerably more expensive than the equivalent
portable. Why? Well, the lab scope was always overdesigned for any
particular job. The bandwidth of the interface had to handle the highest
frequency plugin. The power supplies had to handle the highest current
plugins, in any combination -- enough current at 5 volts for a digital
analyzer plugin, enough higher supply voltage current for a spectrum
analyzer plugin, and so forth. There had to be enough connector pins and
supporting circuitry to handle all possible controls on all possible
plugins. No single configuration ever used more than a fraction of the
built-in mainframe capability. While the portable scope's stages could
have optimal gain, in the lab scopes, the signals always had to be
normalized to the levels specified for the interface. This often
required an extra stage or two for each of the signals being passed
(vertical, Z axis, horizontal, and many controls). Power supplies had to
be decoupled in each plugin at the interface. And finally, good quality,
reliable connectors are much more difficult to find, much more expensive
to buy than you'd think -- and even so, they can easily be the least
reliable components in the system.

Then there's the problem of trying to predict what would be developed in
the future when you design the mainframe, so you can build in the
necessary interface circuitry. And every new plugin (I've designed them)
has to be compatible with every tweak and trick used by all plugins in
the past which it might be used with.

The fact is that hams, for sure, wouldn't pay all the extra money a well
designed plug in system would cost. Of course, I might be wrong --
anyone who thinks so (one particular person comes to mind) should get
busy designing and developing one. Perhaps there's a fortune to be made.
Certainly there's a market for a much simpler plug in system with much
less versatility than the oscilloscope system I described, as a few
manufacturers have shown. The question is, how far can this be taken
before the market dries up due to the increased cost?

Roy Lewallen, W7EL

The fact is that hams, for sure, wouldn't pay all the extra money a well
designed plug in system would cost. Of course, I might be wrong --
anyone who thinks so (one particular person comes to mind) should get busy
designing and developing one. Perhaps there's a fortune to be made.
Certainly there's a market for a much simpler plug in system with much
less versatility than the oscilloscope system I described, as a few
manufacturers have shown. The question is, how far can this be taken
before the market dries up due to the increased cost?

Roy Lewallen, W7EL
=========================================
Would a relatively 'low cost ' plug in card system perhaps be possible by
using standard PCI (computer) or similar card connections for the 'non RF'
connections ,with standard 50 Ohms miniature connectors for all RF
connections.
It would mean that all RF card modules would have a standard RF in- and
output connector using 'miniature coax'.
It would of course mean that all the card modules involving RF would have a
universal 50 Ohms in- and output impedance.
The latter is already promoted by looking at designs in the book
'Experimental Methods in RF Design'

The above referred type of PCI card connections (or any other agreed card
standard )could then be standardised with specific 'edge connections' used
for 'ground' , +5V , -5V , +12 to15 V ,-12 to 15 V , etc

The above would facilitate home brewing and make it possible to combine home
brewed modules with specialised commercial modules. It also would enable
testing modules with standardised (impedance wise) test equipment.
Ready made or blank (single or double sided) PCBs would have identical 'card
fingers' also those supplied as part of a complete kit.

I feel that the amateur radio community would very much benefit of such a
standardised card system.

Although the amateur radio market place is relatively small , with modules
physically standardised , there would be an opportunity for a modest
'cottage industry' .

Frank GM0CSZ / KN6WH

Exactly my point....

We break into two groups of thought here...

Halt at this point, and lay all plans on that halting (and, if ALL the
others don't agree--be bypassed anyway)...

Or, stay with the pack, realizing if that day ever comes (technology ceases
to innovate/obsolete)--we will regret it...

Progress, obsolete equip., is the most desirable thing I can imagine! It is
a given, not all will agree... Indeed, at 52 years of age, my place in the
"scope of the world" is becomming smaller--it only gets worse from now on--I
am not ready to quit and attempt to force others to that "quitting" with
me...

When the "Dick Tracy Wrist Radio" is finally designed and
implemented--perhaps there will be a "death of homebrewers" (I myself am NOT
much of a 'watchbuilder')--but until then we can have fun!

Warmest regards,
John
--
When Viagra fails to work--you are DOOMED!!!

"Mike Coslo" wrote in message
...
| John Smith wrote:
| gb:
|
| Well, we certainly need to examine the "bottle neck" and remove it...
before
| we are doomed...
|
| If we can't institute this "radical" idea here, we need to look at
Canada,
| Mexico, So. America, China, India, etc...
|
| When there are as many functional radios (or "cards") hitting the
dumpster
| as there are functional computers and related equip. (replaced with
| upgrades) we will know the right idea has prevailed and radio has come
| home...
|
| I hope you are kidding, John. That is the absolutely worst part of the
| PC paradigm. Thousands of perfectly good electronics thrown out, often
| made obsolete due to software that is bloated and poorly written (mostly
| OS software. At least old radios are still useable
|
| I would think there must be some EXCELLENT argument/reasoning serving as
a
| road block, or else, others are simply going to pass us by...
|
| The PC paradigm is a poor one, and not to be emulated. PC's will
| finally be mature when we don't have to replace them on almost a yearly
| basis. At that point, software writers will be able to write good
software.
|
| - Mike KB3EIA -

From: "John Smith" on Sun,May 8 2005 1:39 pm

Exactly my point....

We break into two groups of thought here...

...which seems to be YOUR whole point... :-)

Halt at this point, and lay all plans on that halting (and, if ALL the

others don't agree--be bypassed anyway)...

Nihilism. Tsk, tsk...

Or, stay with the pack, realizing if that day ever comes (technology
ceases
to innovate/obsolete)--we will regret it...

What "pack?" What "regrets?" What "ceasing?!?"

Progress, obsolete equip., is the most desirable thing I can imagine!
It is
a given, not all will agree... Indeed, at 52 years of age, my place
in the
"scope of the world" is becomming smaller--it only gets worse from now
on--I
am not ready to quit and attempt to force others to that "quitting"
with
me...

Tsk. Then your card doesn't seem to be plugged in to
the right slot. I have 20 years on you and began in
HF radio communications 52 years ago. What you have to
understand is that EVERYTHING can be made "obsolete"
in the marketplace...HF is NOT used nearly as much for
communications now as back a half century ago. So, you
are "suddenly realizing" your "place in the world" is
getting smaller? Pass me your TS card and I'll punch it.

When the "Dick Tracy Wrist Radio" is finally designed and
implemented--perhaps there will be a "death of homebrewers" (I myself
am NOT
much of a 'watchbuilder')--but until then we can have fun!

I'm wearing one right now. Made by La Crosse. Cost all
of $30 with shipping. "Tunes in" every night to WWVB
and sets itself to the correct time from a kilomile away,
even adjusts for Daylight Savings time. shrug

I'm not sure what everyone is talking about in this thread
but, like Roy and a few others, I've seen some innovative
(and sometimes inventive) work in the many and various
disciplines of "radio" and electronics in the past half
century.

You want "modularity" a la a PC? WHY?!? Because it is
"familiar?" Because it is "cheap?" Here's a clue: This
newsgroup is NOT a "production design and marketing
newsgroup." It isn't a political science discussion
place to whine and moan over some middle-aged anguish
angst attack.

MODULARITY has been going ON in electronics ALL OVER
since the designers stopped trying to use transistors as
if they were vacuum tubes. I have a nicely working Icom
R-70. It is VERY modular, built NOTHING like what a PC
is, NOR SHOULD IT BE. A cast frame and cover that has
a rectangular box form...for convenience on a desk ...but
everything inside is MODULAR, grouped to take different
boards for different models, different functions. Those
MODULES are mostly soldered together, those MODULES
"sitting" in unlikely positions within that box. I have
another receiver, a National NC-57, all tubes, all boat-
anchor, purchased in 1948 with my own money (about $95)
and it works, to be polite, like BADLY in comparison.

Icom has done the MODULAR thing, so has Yaesu, and
Kenwood, and Collins Radio, and even Heathkit. All did
it DIFFERENTLY than any IBM-clone PC. I think ALL the
"radio" makers have done things differently AND done
the MODULARLY...even those that had only ONE module.

On the other hand, I'm typing away at a "slow" PC which
has a processor chugging away at 2.4 GIGAHertz with
memory access rates up in the 100 MEGAHertz range. Now,
from what I've learned and experienced, such frequencies
ARE RADIO. With newer PCs the memory access rates go
above 200 MHz...and the generated RFI is LESS than my
first "powerful" PC with a 20 MHz clock. Why? Better
IC transistor junctions taking LESS operating power.
MUCH LESS. Less power in those state transitions, ergo
less radiated stray RF. Three thousand cheers for that!
I'm looking at an LCD flat screen monitor which is far
better to watch than the old CRT "monitor" and has much
less RFI than that CRT.

I passed 52 some time ago, had maybe 15 minutes of
middle-age angst/worry/regret/etc., shrugged my
shoulders and carried on. There's way TOO MUCH delight
and wonder of all the new things coming out, the
wonderful new (some marvelous improvements on the old)
components, fantastic circuit and system simulation for
"breadboard" trials, all sorts of SOC (systems on a
chip) by mail-order from dozens of vendors. It's a
marvelous fairyland chock full of goodies to use in
all kinds of hobby construction in new and different
ways. Why sit around and contemplate radio navels
and make noises of badness or arouse controversy to
get your anonymous name "known" in a newsgroup?

A very long time ago I learned a truism: Electrons,
fields, and waves don't give a @#$%!!! what humans
think/feel/emote-about. They work by THEIR laws,
NOT by some emotional advertising copy or glossy
looking shelf items nor by the "reviews" in hobby
publications nor by all the cussing at them by
builders who don't know what they should be doing.

Having said that, I'm going to continue putting
together an EPROM burner so that I can complete a
MODULAR SW BC receiver that is single-conversion
with a 21.4 MHz crystal-filtered IF and has a PLL
for the LO. "Auto-bandswitching" just for those
SW BC bands yet the LO tuning range is continuous.
It's in a little BOX made of double-sided PCB
stock, 4" x 8" x 8" in size. Not one microprocessor
in it...done that way on purpose. Could have been
done a decade ago with nearly the same parts.

There's PROGRESS all over the place. If one keeps
one's eyes open. shrug

"John Smith" wrote in message
...
gb:

Well, we certainly need to examine the "bottle neck" and remove it...
before
we are doomed...

If we can't institute this "radical" idea here, we need to look at Canada,
Mexico, So. America, China, India, etc...

JS -

"... before we are all doomed". The only way doom happens is if you don't
do your part in averting that projection. Or are you saying the future is
hopeless?

So, what are you doing to be part of the "solution" rather than being the
"profit of bad things to come?"

How many hours over the past year have you worked with middle or high
schools students volunteering your time? Donating materials, time or money
for educational programs targeted for the audience that will make a
difference?

As George S. Kaufman wrote about money and knowledge in the 1930s - "You
Can't Take it with You".

gb

gb:

Now, here you have a key. The youthful number in any group define its'
likely-hood of survival... it will be "they" who free us from
strangle-holds and limits now imposed...

It will be the vast numbers of youth who end up defining the real future...
without youth--we are all DOOMED (Viagra won't even help!!! grin)

Me? I would like to think, "I am just a guy." In a generic sense, a "John
Smith" of society...

Long time ago I was a boy scout leader, still teach an evening CS course at
a Jr. college (but, have been at odds with admin., my department head, I
think the kids like me (most important--and they are ok...), most women
ditch other instructors/professors to take my course(s)--I like the idea of
them in the field)... many "older" students in my class... this year it is
Java (yuck)...

.... work digital encryption/decryption methods/implementations here, just to
keep out of the unemployment line...

....my first computer was a mainframe, my first desktop an apple--I
recognized a "better idea" (IBM) when it came along... trust me, I am a
"geeky type"...

I set up a network in my garage so I could keep up with youth and remember
mine, but now I have little to offer them, they keep the net and it has
inspired some into the field...

Everyone is aware of my fondness of radio, and I do make known what is
available here--but placed besides IM and internet communications--radio is
a pale color to the net...

I am best at surfing the net, email and newsgroups for "entertainment/hobby
pursuits"... I tinker, now and then with antennas...

.... sorry to bore you... I really am as interesting as a rock!

Warmest regards,
John
--
When Viagra fails to work--you are DOOMED!!!

"gb" wrote in message
...
| "John Smith" wrote in message
| ...
| gb:
|
| Well, we certainly need to examine the "bottle neck" and remove it...
| before
| we are doomed...
|
| If we can't institute this "radical" idea here, we need to look at
Canada,
| Mexico, So. America, China, India, etc...
|
| JS -
|
| "... before we are all doomed". The only way doom happens is if you don't
| do your part in averting that projection. Or are you saying the future is
| hopeless?
|
| So, what are you doing to be part of the "solution" rather than being the
| "profit of bad things to come?"
|
| How many hours over the past year have you worked with middle or high
| schools students volunteering your time? Donating materials, time or
money
| for educational programs targeted for the audience that will make a
| difference?
|
| As George S. Kaufman wrote about money and knowledge in the 1930s - "You
| Can't Take it with You".
|
| gb
|
|

gb wrote:

How many hours over the past year have you worked with middle or high
schools students volunteering your time? Donating materials, time or money
for educational programs targeted for the audience that will make a
difference?


I was a volunteer advisor for the Lake county Florida Vo-Tec
electronics program, till it was shut down. Right now I am trying to
find the money to finish repairs to my four car garage and convert it
into a 1200 sq ft electronics shop to teach basic electronics to the
kids who are still interested. Its not easy when you're 100% disabled
and living on a tiny pension, but I don't give up too easy.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

gb:

Nobel pursuit... in my case, I am more self-centered, I like the company
and people around...

Warmest regards,
John
--
When Viagra fails to work--you are DOOMED!!!

"Michael A. Terrell" wrote in message
...
| gb wrote:
|
| How many hours over the past year have you worked with middle or high
| schools students volunteering your time? Donating materials, time or
money
| for educational programs targeted for the audience that will make a
| difference?
|
|
| I was a volunteer advisor for the Lake county Florida Vo-Tec
| electronics program, till it was shut down. Right now I am trying to
| find the money to finish repairs to my four car garage and convert it
| into a 1200 sq ft electronics shop to teach basic electronics to the
| kids who are still interested. Its not easy when you're 100% disabled
| and living on a tiny pension, but I don't give up too easy.
|
| --
| Former professional electron wrangler.
|
| Michael A. Terrell
| Central Florida