Just perusing the ARRL letter on rec.radio.info and the lead story was
very interesting. It's about the ARRL objecting to the use of some 70cm
frequencies for a commercial event.

This paragraph in particular caught my eye:

"The ARRL called the Miller Motorsports Park choice of
channels 'completely inappropriate. The radio amateurs who
are licensed to use these frequencies are under no obligation
to either tolerate interference or to cease their own operation,
regardless of the interference that might be suffered at any
time' by Miller Motorsports."

Just goes to show how things are different in the US to here in the UK.
Over here we are only secondary users of the 70cm band (the primary user
of just about everything above 2m is the Ministry of Defence) and so we
have to put up with anything and everything, including car alarm keyfobs
on 433.92 MHz as an example. We also only get 430-440 MHz rather than your
420-450.

Even in the 2m band (144-146 not 144-148 MHz..!), of which we are primary
users,we cannot claim protection from interference.

Ah well..!

73 Ivor G6URP

On Sat, 03 May 2008 07:57:45 -0400, Ivor Jones wrote:
Just perusing the ARRL letter on rec.radio.info and the lead story was
very interesting. It's about the ARRL objecting to the use of some 70cm

frequencies for a commercial event.

.....
Just goes to show how things are different in the US to here in the UK.
Over here we are only secondary users of the 70cm band (the primary use
r
of just about everything above 2m is the Ministry of Defence) and so we
have to put up with anything and everything, including car alarm keyfob
s
on 433.92 MHz as an example. We also only get 430-440 MHz rather than
your 420-450.

If I recall properly we're secondary to the military in
that band as well. Indeed, 70cm repeater operators are learning that the
hard way... as many repeaters are having to reduce power or even go QRT
at the request of our military, to protect a radar system.

But the motorsports folks have no regular authority in that band at all.

I'm not sure I understand why they thought they needed amateur spectrum
for that project.

Doug Smith W9WI wrote:
If I recall properly we're secondary to the military in
that [70cm] band as well. Indeed, 70cm repeater operators are learning that the
hard way... as many repeaters are having to reduce power or even go QRT
at the request of our military, to protect a radar system.

But the motorsports folks have no regular authority in that band at all.

I'm not sure I understand why they thought they needed amateur spectrum
for that project.



The Pave/Paws system that is pushing some repeaters off 70cm predates
the complaints by several decades, and I take the military's new
attitude to be another nail in the coffin of ham radio's former
"favorite son" status at the Pentagon.

It used to be that we hams were a corps of operators who could be
pressed into service quickly during a war or other crisis. Now, with
Morse as deeply buried as its creators and military electronics too
secret to be entrusted to soldiers and sailors who haven't been vetted
for security clearances, we're yesterday's news in the E ring.

We'll have to find another reason to justify the allocations we enjoy.
It's going to be hard work, and not nearly as easy as learning Morse
(not that that would help now). We're going to have to get better - in
fact, much better - at public relations: the Red Cross and other
disaster relief agencies have known the importance of image all along,
but now hams have got to get in the game and advertise ourselves as an
anlternative to traditional communications during hurricanes, floods,
earthquakes, etc.

Of course we've had this debate before. Older hams such as I feel that
we followed the program and did what was expected of us, and now I
resend being pushed aside in favor of a Federal Emergency Management
Agency which is, to my jaundiced eye, proficient only at promising what
others will have to deliver and claiming credit for what others have
done. It's a cold, cruel world, and we must get better at telling the
public and the their elected officials how much we do.

Bill

--
Bill Horne, W1AC

(Remove QRM from my address for direct replies.)

Anyone with some level of technical knowledge might wonder why a
billion dollar (boondoggle) "radar system" can't discriminate between
a fixed, known "target" (like a repeater)and one that is moving, comes
from over the horizon which might be something nasty?

Sounds like some real shoddy engineering took place at taxpayer
expense. I can think of 3 or 4 ways to remove false targets w/o
loosing any system level accuracy or sensitivity. In fact, didn't
they perfect that during the cold war?

Gee... Thinking about it some. All Abdulah (or Ivan or whoever)
needs to do is buy a 440 rig, an amp and a yagi and go out as a
"rover"; 3 or 4 kW ERP down the bear's craw for a while then move.

Sigh....


On Sat, 3 May 2008 23:16:09 EDT, Bill Horne wrote:

Doug Smith W9WI wrote:
If I recall properly we're secondary to the military in
that [70cm] band as well. Indeed, 70cm repeater operators are learning that the
hard way... as many repeaters are having to reduce power or even go QRT
at the request of our military, to protect a radar system.

But the motorsports folks have no regular authority in that band at all.

I'm not sure I understand why they thought they needed amateur spectrum
for that project.



The Pave/Paws system that is pushing some repeaters off 70cm predates
the complaints by several decades, and I take the military's new
attitude to be another nail in the coffin of ham radio's former
"favorite son" status at the Pentagon.

It used to be that we hams were a corps of operators who could be
pressed into service quickly during a war or other crisis. Now, with
Morse as deeply buried as its creators and military electronics too
secret to be entrusted to soldiers and sailors who haven't been vetted
for security clearances, we're yesterday's news in the E ring.

We'll have to find another reason to justify the allocations we enjoy.
It's going to be hard work, and not nearly as easy as learning Morse
(not that that would help now). We're going to have to get better - in
fact, much better - at public relations: the Red Cross and other
disaster relief agencies have known the importance of image all along,
but now hams have got to get in the game and advertise ourselves as an
anlternative to traditional communications during hurricanes, floods,
earthquakes, etc.

Of course we've had this debate before. Older hams such as I feel that
we followed the program and did what was expected of us, and now I
resend being pushed aside in favor of a Federal Emergency Management
Agency which is, to my jaundiced eye, proficient only at promising what
others will have to deliver and claiming credit for what others have
done. It's a cold, cruel world, and we must get better at telling the
public and the their elected officials how much we do.

Bill

In article ,
Bill Powell wrote:

Anyone with some level of technical knowledge might wonder why a
billion dollar (boondoggle) "radar system" can't discriminate between
a fixed, known "target" (like a repeater)and one that is moving, comes
from over the horizon which might be something nasty?

Sounds like some real shoddy engineering took place at taxpayer
expense. I can think of 3 or 4 ways to remove false targets w/o
loosing any system level accuracy or sensitivity. In fact, didn't
they perfect that during the cold war?

Take a look at this month's issue of CQ for a possible explanation of
the problem.

To sum it up briefly: PAVE PAWS is a phased-array radar system, with
a large number of individual turnstile antennas on each side. During
reception, the signals picked up by the various individual antennas
are combined electrically/electronically, in ways which cause them to
mix in-pase for signals coming from the desired direction and
out-of-phase for other directions.

Older-generation phased array antenna systems perform the phase
shifting by switching individual phase shifters (delay lines or
similar) in series with the feedlines from the individual antennas.
The delayed signals are then combined and detected. If you want to
point the beam in a different direction, you change all of the
phase-shifter delays.

The newer generation of phased-array radar systems actually digitizes
the incoming signal at each antenna, and then does the linear mixing
(addition/subtraction) entirely in the digital domain.

Why the change? I gather that it allows for both a finer degree of
control of the delays (allowing higher resolution in beam-pointing),
and also allows multiple different delay-and-combine operations to be
performed in parallel (just add banks of DSPs), allowing one to track
multiple targets simultanously.

The disadvantage of this new system (as stated in CQ): it has rather
less ability to reject off-axis signals than the older delay-line
method of phasing. In the delay-line system, off-axis interference
would tend mix out-of-phase *before* it was detected, and would
largely cancel out. In the new system, *every* individual antenna and
digitizer receives the interfering signal at full strength - there's
no phase cancellation in the analog domain.

This would leave the newer systems at a significant disadvantage with
regard to saturation and desensitization by strong off-axis signals.
It's not so much a question of false targets appearing, I think, but a
question of the system losing the ability to detect the real targets.
The digigal method of doing phase-shifting and beamforming is faster
and more precise than the switched-analog method, but apparently
somewhat less robust in this regard.

As Scotty said, "The more complicated they make the plumbing, the
easier it is to plug up the drains."

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Bill Powell wrote:
Anyone with some level of technical knowledge might wonder why a
billion dollar (boondoggle) "radar system" can't discriminate between
a fixed, known "target" (like a repeater)and one that is moving, comes
from over the horizon which might be something nasty?

Even weather radar can do that with drops of water. :-)
--
73, Cecil http://www.w5dxp.com

(Bill Powell) wrote in
:

Sounds like some real shoddy engineering took place at taxpayer
expense. I can think of 3 or 4 ways to remove false targets w/o
loosing any system level accuracy or sensitivity. In fact, didn't
they perfect that during the cold war?

If I was trying to do real-time analysis of such weak signals with the
goal of protecting the nation, I'd take advantage of every technical
and legal option available to me to limit or remove the potential for
interference from very strong local signal sources.

Do you also object to the "National Radio Quiet Zone" in West
Virginia?

--
Bert Hyman | St. Paul, MN |

Bill Horne wrote on Sat 3 May 2008 under the thread 'Discussions' in
RRAM:

The Pave/Paws system that is pushing some repeaters off 70cm predates
the complaints by several decades, and I take the military's new
attitude to be another nail in the coffin of ham radio's former
"favorite son" status at the Pentagon.

As a veteran of the US Army Signal Corps 1952 to 1960 and as an
engineer who has been involved in DoD electronics during my
civilian career, I've seen NO evidence that US amateur radio
was ever in some "favorite son" status in the US military.

It used to be that we hams were a corps of operators who could be
pressed into service quickly during a war or other crisis.

Perhaps this was true in 1941. It was NOT true in 1952 when I
voluntarily entered US Army service (during the Korean War active
phase), trained at the Signal School at Fort Monmouth, NJ, and
subsequently assigned to long-distance, high-volume message
traffic handling on a 24/7 basis at a Far East Command Hq
station in Tokyo. I served in that assignment for three years,
had access to documents and reports on communications within
the military and queried many on the (then) modern methods of
communications by radio.

From the military point of view of 56 years ago, having an
interest in radio or the more general electronics field is only
important towards assignment in a particular military occupation
specialty (still familiarly called 'MOS'). Knowing on-off keying
CW skills via amateur radio MIGHT get one assigned to Field Radio
school (then the only Army MOS actually requiring OOK CW skill).
Field Radio MOS then involved using HF from a truck-transportable
station that was also equipped with teleprinters; teleprinted
messaging was the norm in the Korean War (active phase '50-'53).
The MAJORITY of 'radio' communications back then, a half century
ago, was by VOICE and that over line-of-sight ranges. Military
radio plans in the field were already organized into three
overlapping radio bands from high HF into low VHF, the bands
subdivided for infantry-artillery-armor unit use. No one needed
any morse code skills to operate those radios then. Indeed, it
was more akin to one-way talking on a telephone, something that
most civilians had already done in the 1950s.

Now, with
Morse as deeply buried as its creators and military electronics too
secret to be entrusted to soldiers and sailors who haven't been vetted
for security clearances, we're yesterday's news in the E ring.

I have NOT seen any of that "burial" nor of the "secrecy" alleged
to any Pentagon "ring" in my Army service nor in the many years
that followed as a civilian working on DoD contracts involving
communications. The "secrecy" is actually on a very low
Confidential level, the lowest of the three classifications. As
a matter of fact, most Army radios of a half century ago where
NOT used by signal personnel nor did they ever require any sort
of security classification; no more so than revealing ANY military
information to the enemy on anything.

I have no personal knowledge of what actually transpires in ANY
"ring" of the Pentagon. I must depend on periodicals and documents
published by defense electronics and electronics professional
associations to yield such information. In those, and in archived
copies of "Signal" (a quarterly of the Army Signal Corps, available
new to signal personnel) there has been NO such statements of any
"favoritism" expressed from a half century ago to today.

SECRECY in communications is regularly carried out today by UNvetted
"soldiers and sailors" using a variety of cryptologically embedded
(but selectable) means within radios. The standard small-unit
(battalion or below) field radio is the SINCGARS family operating
30 to 88 MHz. The first SINCGARS went operational in 1989, almost
two decades ago. Over 300,000 R/Ts basic to the AN/PRC-119 man-pack
transceiver have been built by ITT, Fort Wayne, IN. More are
available in HTs built by other firms plus the contracts awarded to
Harris Corporation for newer, smaller SINCGARS-compatible multi-
band radios. All of that family have their coding set by a "hopset"
entry (encryption key and frequency-hopping sequence settings) which
IS controlled by a "vetted" signal officer. The actual coding
method is digital, beginning with a pseudo-random sequence generator
involving digital feedback of a digital shift register could be
known by an unfriendly...but the permutations of possible keys is
so large that it is impractical for them to carry around super-
computers in the field to defeat the cryptology in time to be
effective. Note: The electronics technology to do all that has been
known (and most things published about it openly) for over three
decades, some of it public for four decades. In short, today's
US military CAN use very robust, secure codes to allow UNvetted
military personnel to communicate. They have had the capability
to do so for nearly two decades.

PAVE PAWS has been around for decades. It is in the technology
classification using multiple receivers to decrease the antenna
beam width with an ability to enhance phase shifting of the incoming
wavefront (allows other processing refinements of returns). Anyone
can gather information on its general technological structure.
Since it IS primary in its assigned operating frequency and IS part of
National Defense, that National Defense ought to be considered
primary by US citizens who wish to survive. Is a radio hobby
more important than national survival?

We'll have to find another reason to justify the allocations we enjoy.
It's going to be hard work, and not nearly as easy as learning Morse
(not that that would help now). We're going to have to get better - in
fact, much better - at public relations: the Red Cross and other
disaster relief agencies have known the importance of image all along,
but now hams have got to get in the game and advertise ourselves as an
anlternative to traditional communications during hurricanes, floods,
earthquakes, etc.

Please leave the morse code test issue OUT. That has been settled
for US amateur radio by the FCC after much, much debate for too long
a time.

IMAGE for the general public MUST be aimed OUTSIDE of amateur radio
publications. It cannot remain the insider topic WITHIN amateur
radio groups or publications. If it is REALLY there then it could
(and should) get out into the mainstream. Such emergency good works
news just haven't gotten out to the general public. The public sees
FCC issues as they affect broadcasting and cell phones in the national
news. maybe something about business radio of public safety radio.
Amateur radio news is not an important issue for such media.
The public has rarely seen amateur radio communications during
emergencies during national news...it HAS seen various National Guard
units and local government agencies doing communications on the news,
including FEMA equipment (going back to 1994 and the Northridge
Earthquake in January with quickly-transported video message displays
relayed by satellite for their own health-and-welfare messages seen
in handwriting of senders and shown on local TV).

I'm not going to comment on the Katrina hurricane situation. That
involves many more NON-amateur radio policies among local and state
agencies. The Katrina hurricane happened over two years ago and
the USA has had more emergencies since then. Rehashing the Katrina
situation does NO good in attempting to get the word out to the
general public about amateur radio. If ham radio is really as good
as some declare it, it should be worth national attention. It has
gotten very little on the national news in the last half century.
QED.

One thing that should NOT continue is to keep thinking in the
paradigms of pre-WWII 'radio' as is often presented in amateur
radio magazines. Technology has gone through several plateau jumps
of advancement since that long-ago time. Fantasies of some amateur
radio licensees are still rooted to back then. Those are lost in
the reality of today's radio capabilites and uses. The general
public has its own fantasies and it is foolish to attempt trying
to tell them other fantasies.

Amateur radio is a HOBBY. Let's try to focus on that.

Model vehicles are a hobby for others. The Academy of Model
Aeronautics doesn't pretend to advance the state of the art of
aviation but it was successful in lobbying for a hundred
frequency channels for radio-control two decades ago. Consider
that hobbyists are citizens and that the US government does
listen to its citizens. Work from that basis.

Leonard H. Anderson AF6AY

(Life Member)

On Mon, 5 May 2008 11:34:06 EDT, Bert Hyman wrote:

(Bill Powell) wrote in
:

Sounds like some real shoddy engineering took place at taxpayer
expense. I can think of 3 or 4 ways to remove false targets w/o
loosing any system level accuracy or sensitivity. In fact, didn't
they perfect that during the cold war?

If I was trying to do real-time analysis of such weak signals with the
goal of protecting the nation, I'd take advantage of every technical
and legal option available to me to limit or remove the potential for
interference from very strong local signal sources.
Technical for sure but it appears that even technology available to
the general public isn't in (effective) use.
A known and fixed "target" in ANY digital processing system is very
easily noted and then removed from the data stream.
Legal resources? Sounds like the typical "When all else fails, blame
the ham" excuse.

Do you also object to the "National Radio Quiet Zone" in West
Virginia?
Absolutely not! And, all a ham has to do there is to coordinate in
advance. They have MANY issues with RFI from non-ham sources to
contend with there.
Wonder if PAVEPAWS is going to start shutting down microwave ovens and
wireless dog fences next? :-)

Bp
PS - No complaints w/ the government entity but w/ the contractor(s).

On May 3, 11:16�pm, Bill Horne wrote:
Doug Smith W9WI wrote:
If I recall properly we're secondary to the military in
that [70cm] band as well.

But the motorsports folks have no regular authority in that band at
all.

I'm not sure I understand why they thought they needed
amateur spectrum for that project. �

They obviously don't understand what amateur radio is all about.

The Pave/Paws system that is pushing some repeaters off 70cm predates
the complaints by several decades, and I take the military's new
attitude to be another nail in the coffin of ham radio's former
"favorite son" status at the Pentagon.

Maybe - or maybe not. Secondary status means no interference need be
tolerated by the primary.

There used to be a 50 watt limit on 420-450 MHz for amateurs due to
the possibility of interference to radar.

It used to be that we hams were a corps of operators who could
be pressed into service quickly during a war or other crisis.

That's still the case. But it doesn't mean that the primary users of a
band have to put up with interference from secondary users.

Now, with Morse as deeply buried as its creators and military
electronics too
secret to be entrusted to soldiers and sailors who haven't
been vetted
for security clearances, we're yesterday's news in the E ring.

I'm not sure what you mean by "Morse as deeply buried as its
creators".

We hams continue to use Morse Code on the air - extensively, too!
MARS is running Morse Code nets again, on an experimental basis.

It's true that Morse Code has all but been eliminated by the US
military for its own communications uses. That's no surprise, even
though Morse Code was used extensively by the US military in both
World Wars, Korea, and Vietnam. But that doesn't mean hams should stop
using Morse Code.

We'll have to find another reason to justify the allocations we
enjoy.

How about these:

1) Public service communications (not just in emergencies, but for
events like parades, marathons, bike races, etc.) Remember the search
for Space Shuttle debris a few years back? Amateurs provided
communications for at least some search groups, and it turned out to
be more useful and flexible than cell phones or other radio services.

2) Education in radio and electronics. Learn-by-doing, IOW. Recently,
ARRL ran a homebrew contest to design a 40 meter CW/SSB transceiver
that would use less than $50 in parts. Several entries met all the
requirements, and a winner was recently announced. What better way to
learn radio than by building an operating a homebrew station?

3) Historical preservation. We have museums, historic districts, etc.,
in other areas, why not in radio? We hams have shown that old and new
technologies can coexist, and an active operation is so much better
than a dry nonfunctional museum display.

4) Experimentation/wilderness area. Most of the rest of the radio
spectrum is channelized, digitized, and carefully planned as to its
users and uses. The amateur bands are like a wilderness area, without
all the central planning and channelization, where operator skill and
technical knowhow can try all sorts of new and old things.
And where all citizens who can pass the basic tests for a license have
access to lots of spectrum, modes, and activities.

It's going to be hard work, and not nearly as easy as learning
Morse (not that that would help now).

Morse Code is still worth learning, IMHO.

We're going to have to get better - in
fact, much better - at public relations: the Red Cross and other
disaster relief agencies have known the importance of image all
along,
but now hams have got to get in the game and advertise ourselves
as an
anlternative to traditional communications during hurricanes,
floods, earthquakes, etc.

Agreed - but also as a fun thing to do. Emergency and public service
comms are just one part of what hams do.

The key factor is that the "served agencies" want different things
today in the way of communications. In some emergencies they won't
need hams at all, in others they will really need amateurs to help
out. But they're the customer, as it were.




73 de Jim, N2EY