David Lesher wrote:

writes:

The FAA is planning as decommissioning as much ground equipment as

s/planning as/desperately hoping to/

possible. A primary driver for next-gen is the high cost of operating
and maintaining the ground based primary and secondary radars. A lot
of that stuff is quite old.

As noted by the fact they must buy tubes [yes, those things that glow..]
for some ARSR's [the longer-range radars] from St. Petersburg, and not
the Florida one. (The paperwork for an agency to procure things overseas
is mind-boggling; ISTM this actually has to get Hill approval.)


Which they wouldn't have to do, if our tax laws hadn't put the
domestic OEMs out of business. The cost to tool up for a small
production is high, and the ignorant tax laws killed them on inventory.
They did as much to kill US built electronics, as cheap imports.

Richardson Electronics has picked up most of the residue form domestic
transmitting tube capabilities.


There is indeed a lot of concern over the loss of too much
infrastructure that can track uncooperative targets that can now be
tracked with primary radar, and how many radars are to remain is being
debated.


Output power for modular solid state microwave gear keeps climbing.
If they can build 5 MW UHF TV transmitters, they can build acceptable
solid state modular RADAR gear. The new solid state receivers have a
lot lower noise floor, which reduces the raw RF that has to be
transmitted, as well.


ITYM "There's a pitched battle under way....with blood flowing down the
corrridors at 800 Independence Ave..."

As far as I can tell, many terminal (limited coverage) primary radars
will be retained, but fewer en-route radars will be kept operational.

"Depending on who is winning on a given day..."


--
You can't have a sense of humor, if you have no sense!

Stealth Pilot wrote:

On Thu, 4 Jun 2009 09:22:27 -0500, "Robert Swinney"
wrote:

Excite today carried a piece re. the S. American crash and location of planes over the ocean. It
went on to say that radar can't see beyond about 200 miles (let alone the fact that bending radar
coverage beyond LOS is pretty remarkable in its own right).

standard radar is line of sight.
we australians have an over the horizon radar which is pretty
remarkable.
I think our guys lead the world with the technology.


the first RADAR systems used in W.W.II was over the horizon, but it
wasn't intended to be. Quite a few 'Ghost fleets' were spotted, and
according to their displays, it should have been plainly visible, when
in fact they were well outside the design range. Then reports came in
of enemy ships being spotted at exactly one or two times the displayed
distance. They finally determined it was due to the low frequency that
the early RADAR systems used.

--
You can't have a sense of humor, if you have no sense!

On Fri, 5 Jun 2009 20:37:44 -0700, "Bill Noble"
wrote:


"Stealth Pilot" wrote in message
.. .
On Thu, 4 Jun 2009 09:22:27 -0500, "Robert Swinney"
wrote:

Excite today carried a piece re. the S. American crash and location of
planes over the ocean. It
went on to say that radar can't see beyond about 200 miles (let alone the
fact that bending radar
coverage beyond LOS is pretty remarkable in its own right).

standard radar is line of sight.
we australians have an over the horizon radar which is pretty
remarkable.
I think our guys lead the world with the technology.

Stealth Pilot


Pave Paws has been around a long time
http://en.wikipedia.org/wiki/PAVE_PAWS

depending on frequency, you can get ducting, particularly when it is warm an
humid
theweatherprediction.com/habyhints/234/
en.wikipedia.org/wiki/Atmospheric_ducting
ieeexplore.ieee.org/iel2/810/1796/00047637.pdf?arnumber=47637


Bill I can assure you that the australian system isnt Pave Paws or
anything like it.
do a google search on Jindalee and JORN

Stealth Pilot

On Sat, 06 Jun 2009 01:14:07 -0400, "Michael A. Terrell"
wrote:


Stealth Pilot wrote:

On Thu, 4 Jun 2009 09:22:27 -0500, "Robert Swinney"
wrote:

Excite today carried a piece re. the S. American crash and location of planes over the ocean. It
went on to say that radar can't see beyond about 200 miles (let alone the fact that bending radar
coverage beyond LOS is pretty remarkable in its own right).

standard radar is line of sight.
we australians have an over the horizon radar which is pretty
remarkable.
I think our guys lead the world with the technology.


the first RADAR systems used in W.W.II was over the horizon, but it
wasn't intended to be. Quite a few 'Ghost fleets' were spotted, and
according to their displays, it should have been plainly visible, when
in fact they were well outside the design range. Then reports came in
of enemy ships being spotted at exactly one or two times the displayed
distance. They finally determined it was due to the low frequency that
the early RADAR systems used.

the frequency may have been right for the conditions but the cause was
ionospheric reflection.

Stealth Pilot

On Jun 6, 4:25*am, Stealth Pilot
wrote:
On Sat, 06 Jun 2009 01:14:07 -0400, "Michael A. Terrell"

* the first RADAR systems used in W.W.II was over the horizon, but it
wasn't intended to be. *Quite a few 'Ghost fleets' were spotted, and
according to their displays, it should have been plainly visible, when
in fact they were well outside the design range. *Then reports came in
of enemy ships being spotted at exactly one or two times the displayed
distance. *They finally determined it was due to the low frequency that
the early RADAR systems used.

the frequency may have been right for the conditions but the cause was
ionospheric reflection.

Stealth Pilot-

Some were too short for skip. Early in WW2 there was a serious
invasion scare in SoCal when a radar picked up the seagulls over a
garbage scow about 60 miles out.

What's Carlos Kopp doing now? I haven't heard from him in quite a
while.

jsw

In article ,
Stealth Pilot wrote:

On Sat, 06 Jun 2009 01:14:07 -0400, "Michael A. Terrell"
wrote:


Stealth Pilot wrote:

On Thu, 4 Jun 2009 09:22:27 -0500, "Robert Swinney"
wrote:

Excite today carried a piece re. the S. American crash and location of
planes over the ocean. It
went on to say that radar can't see beyond about 200 miles (let alone the
fact that bending radar
coverage beyond LOS is pretty remarkable in its own right).

standard radar is line of sight.
we australians have an over the horizon radar which is pretty
remarkable.
I think our guys lead the world with the technology.


the first RADAR systems used in W.W.II was over the horizon, but it
wasn't intended to be. Quite a few 'Ghost fleets' were spotted, and
according to their displays, it should have been plainly visible, when
in fact they were well outside the design range. Then reports came in
of enemy ships being spotted at exactly one or two times the displayed
distance. They finally determined it was due to the low frequency that
the early RADAR systems used.

the frequency may have been right for the conditions but the cause was
ionospheric reflection.

It's not the frequency that causes such ghosts, it's the pulse
repetition frequency that matters.

A pulse radar periodically transmits pulses, listens for echoes between
the transmits, and assumes that received echoes came from the
immediately preceding transmit. Which isn't necessarily true. A large
reflector can have a loud-enough echo from several transmit pulses ago,
making it look like there is a nearby target.

This is called a "second time around" echo (even if its really third
time, et al).

The standard solution is to vary the period between transmit pulses.
Real echoes will not change their apparent range, while N-time-around
echoes will move in predictable ways.

Joe Gwinn

In article ,
"Michael A. Terrell" wrote:

David Lesher wrote:

writes:

The FAA is planning as decommissioning as much ground equipment as

s/planning as/desperately hoping to/

possible. A primary driver for next-gen is the high cost of operating
and maintaining the ground based primary and secondary radars. A lot
of that stuff is quite old.

As noted by the fact they must buy tubes [yes, those things that glow..]
for some ARSR's [the longer-range radars] from St. Petersburg, and not
the Florida one. (The paperwork for an agency to procure things overseas
is mind-boggling; ISTM this actually has to get Hill approval.)


Which they wouldn't have to do, if our tax laws hadn't put the
domestic OEMs out of business. The cost to tool up for a small
production is high, and the ignorant tax laws killed them on inventory.
They did as much to kill US built electronics, as cheap imports.

Richardson Electronics has picked up most of the residue form domestic
transmitting tube capabilities.


There is indeed a lot of concern over the loss of too much
infrastructure that can track uncooperative targets that can now be
tracked with primary radar, and how many radars are to remain is being
debated.


Output power for modular solid state microwave gear keeps climbing.
If they can build 5 MW UHF TV transmitters, they can build acceptable
solid state modular RADAR gear. The new solid state receivers have a
lot lower noise floor, which reduces the raw RF that has to be
transmitted, as well.

Solid state UHF radar transmitters have been around since the 1980s.

http://www.fas.org/spp/military/program/track/pavepaws.htm

The purchase price is higher than vacuum tube, but the maintenance cost
is lower, especially for systems that must operate 24x7x365 with ~100%
availability.

Joe Gwinn

"Jim Wilkins" wrote in message
...
On Jun 6, 4:25 am, Stealth Pilot
wrote:
On Sat, 06 Jun 2009 01:14:07 -0400, "Michael A. Terrell"

the first RADAR systems used in W.W.II was over the horizon, but it
wasn't intended to be. Quite a few 'Ghost fleets' were spotted, and
according to their displays, it should have been plainly visible, when
in fact they were well outside the design range. Then reports came in
of enemy ships being spotted at exactly one or two times the displayed
distance. They finally determined it was due to the low frequency that
the early RADAR systems used.

the frequency may have been right for the conditions but the cause was
ionospheric reflection.

Stealth Pilot-

Some were too short for skip. Early in WW2 there was a serious
invasion scare in SoCal when a radar picked up the seagulls over a
garbage scow about 60 miles out.

What's Carlos Kopp doing now? I haven't heard from him in quite a
while.

jsw

While in development, I was operating an X band monopulse radar with a long
focal length (120") TV camera mounted on the side. I picked up a target of
opportunity and locked on. In my TV screen was a mountain. The cross hairs
were moving about so I just left it locked on and watched. Suddently out
from behind the mountain appeared a 747 with the shuttle on board. I had
been skin tracking that large target in back of a mountain.
There was a US based VLF OverThe Horizon radar project back in the early
90s that was able to track and assist an airliner in trouble out over the
Atlantic. It used a fairly large set of arrays that occupied a bit of real
estate. This project may have been a funding fatality.

On Sat, 06 Jun 2009 08:23:15 GMT, the infamous Stealth Pilot
scrawled the following:

On Fri, 5 Jun 2009 20:37:44 -0700, "Bill Noble"
wrote:
Pave Paws has been around a long time
http://en.wikipedia.org/wiki/PAVE_PAWS

depending on frequency, you can get ducting, particularly when it is warm an
humid
theweatherprediction.com/habyhints/234/
en.wikipedia.org/wiki/Atmospheric_ducting
ieeexplore.ieee.org/iel2/810/1796/00047637.pdf?arnumber=47637


Bill I can assure you that the australian system isnt Pave Paws or
anything like it.
do a google search on Jindalee and JORN

http://en.wikipedia.org/wiki/Over_the_horizon_radar has a good
overview. Your Jindalee system seems to be the newest innovation.

---
So far Mr. Obama has used his personally exciting presidency for initiatives
that are spending public money on a scale not seen since ancient Egypt.
-- Daniel Henninger
WSJ Online, 4 June 2009
"Obama's America: Too Fat to Fail
The age of the induced industrial coma."

"Joseph Gwinn" wrote in message
...
In article ,
Stealth Pilot wrote:

On Sat, 06 Jun 2009 01:14:07 -0400, "Michael A. Terrell"
wrote:


Stealth Pilot wrote:

On Thu, 4 Jun 2009 09:22:27 -0500, "Robert Swinney"
wrote:

Excite today carried a piece re. the S. American crash and location
of
planes over the ocean. It
went on to say that radar can't see beyond about 200 miles (let alone
the
fact that bending radar
coverage beyond LOS is pretty remarkable in its own right).

standard radar is line of sight.
we australians have an over the horizon radar which is pretty
remarkable.
I think our guys lead the world with the technology.


the first RADAR systems used in W.W.II was over the horizon, but it
wasn't intended to be. Quite a few 'Ghost fleets' were spotted, and
according to their displays, it should have been plainly visible, when
in fact they were well outside the design range. Then reports came in
of enemy ships being spotted at exactly one or two times the displayed
distance. They finally determined it was due to the low frequency that
the early RADAR systems used.

the frequency may have been right for the conditions but the cause was
ionospheric reflection.

It's not the frequency that causes such ghosts, it's the pulse
repetition frequency that matters.

A pulse radar periodically transmits pulses, listens for echoes between
the transmits, and assumes that received echoes came from the
immediately preceding transmit. Which isn't necessarily true. A large
reflector can have a loud-enough echo from several transmit pulses ago,
making it look like there is a nearby target.

This is called a "second time around" echo (even if its really third
time, et al).

The standard solution is to vary the period between transmit pulses.
Real echoes will not change their apparent range, while N-time-around
echoes will move in predictable ways.

Joe Gwinn

Joe you sound like a Radar Rat. The Nth time around trackers are used in
deep space tracking all the time. Have you been associated with them?
Stu (Radar Rat from NWC and Kwaj)

On Jun 6, 4:00*pm, Joseph Gwinn wrote:

A pulse radar periodically transmits pulses, listens for echoes between
the transmits, and assumes that received echoes came from the
immediately preceding transmit. *Which isn't necessarily true. *A large
reflector can have a loud-enough echo from several transmit pulses ago,
making it look like there is a nearby target. *

This is called a "second time around" echo (even if its really third
time, et al).

The standard solution is to vary the period between transmit pulses. *
Real echoes will not change their apparent range, while N-time-around
echoes will move in predictable ways.

Joe Gwinn

Another solution is to not send a pulse, and when you do not get a
pulse back, you know how long it took for the pulse to not go out and
return. This was used on the Verlort radar to track targets at 1000
miles or so.

Dan

In article
,
" wrote:

On Jun 6, 4:00*pm, Joseph Gwinn wrote:

A pulse radar periodically transmits pulses, listens for echoes between
the transmits, and assumes that received echoes came from the
immediately preceding transmit. *Which isn't necessarily true. *A large
reflector can have a loud-enough echo from several transmit pulses ago,
making it look like there is a nearby target. *

This is called a "second time around" echo (even if its really third
time, et al).

The standard solution is to vary the period between transmit pulses. *
Real echoes will not change their apparent range, while N-time-around
echoes will move in predictable ways.

Joe Gwinn

Another solution is to not send a pulse, and when you do not get a
pulse back, you know how long it took for the pulse to not go out and
return. This was used on the Verlort radar to track targets at 1000
miles or so.

I hadn't heard of the Verlort radar, but google yields some articles
that say that it was an early staggered PRI (Pules Repetition Interval)
system. There are most certainly pulses, but the interval between
successive pulses jumps about, and in a short period of time the radar
accumulates enough information to figure out the true range.

Joe Gwinn

In article ,
"Stu Fields" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
Stealth Pilot wrote:

On Sat, 06 Jun 2009 01:14:07 -0400, "Michael A. Terrell"
wrote:


Stealth Pilot wrote:

On Thu, 4 Jun 2009 09:22:27 -0500, "Robert Swinney"
wrote:

Excite today carried a piece re. the S. American crash and location
of
planes over the ocean. It
went on to say that radar can't see beyond about 200 miles (let alone
the
fact that bending radar
coverage beyond LOS is pretty remarkable in its own right).

standard radar is line of sight.
we australians have an over the horizon radar which is pretty
remarkable.
I think our guys lead the world with the technology.


the first RADAR systems used in W.W.II was over the horizon, but it
wasn't intended to be. Quite a few 'Ghost fleets' were spotted, and
according to their displays, it should have been plainly visible, when
in fact they were well outside the design range. Then reports came in
of enemy ships being spotted at exactly one or two times the displayed
distance. They finally determined it was due to the low frequency that
the early RADAR systems used.

the frequency may have been right for the conditions but the cause was
ionospheric reflection.

It's not the frequency that causes such ghosts, it's the pulse
repetition frequency that matters.

A pulse radar periodically transmits pulses, listens for echoes between
the transmits, and assumes that received echoes came from the
immediately preceding transmit. Which isn't necessarily true. A large
reflector can have a loud-enough echo from several transmit pulses ago,
making it look like there is a nearby target.

This is called a "second time around" echo (even if its really third
time, et al).

The standard solution is to vary the period between transmit pulses.
Real echoes will not change their apparent range, while N-time-around
echoes will move in predictable ways.

Joe Gwinn

Joe you sound like a Radar Rat. The Nth time around trackers are used in
deep space tracking all the time. Have you been associated with them?
Stu (Radar Rat from NWC and Kwaj)

I've been working on radars for decades, a mix of military and air
traffic control, plus some to track surface shipping in crowded areas.
Not to mention dabbling in a surface-ship sonar or two. But no deep
space radars.

Joe Gwinn

On Jun 6, 9:51*pm, Joseph Gwinn wrote:
In article
,



" wrote:
On Jun 6, 4:00*pm, Joseph Gwinn wrote:

A pulse radar periodically transmits pulses, listens for echoes between
the transmits, and assumes that received echoes came from the
immediately preceding transmit. *Which isn't necessarily true. *A large
reflector can have a loud-enough echo from several transmit pulses ago,
making it look like there is a nearby target. *

This is called a "second time around" echo (even if its really third
time, et al).

The standard solution is to vary the period between transmit pulses. *
Real echoes will not change their apparent range, while N-time-around
echoes will move in predictable ways.

Joe Gwinn

Another solution is to not send a pulse, and when you do not get a
pulse back, you know how long it took for the pulse to not go out and
return. *This was used on the Verlort radar to track targets at 1000
miles or so.

I hadn't heard of the Verlort radar, but google yields some articles
that say that it was an early staggered PRI (Pules Repetition Interval)
system. *There are most certainly pulses, but the interval between
successive pulses jumps about, and in a short period of time the radar
accumulates enough information to figure out the true range.

Joe Gwinn

No, it sent a continuous string of pulses at a PRI so that it could
autotrack. When the pulse rate was such that it would be receiving a
pulse close to the time when it was transmitting a pulse, it changed
pulse rates. But it also autotracked the range. So to get the range
set correctly it would not send a pulse. And when no pulse showed up
when expected, it knew how long it took for a pulse to go out and
return ( the actual time was a bit longer as the target had to have a
transponder. The distances were much too far to skin track. ). After
it had the range autotracking, it sent continuous strings of pulses
and just varied the pulse rate when the received pulse would be masked
by transmitting.

I also did some searching and found an article that said there was a
38 pps rate for range. It may have been true for some verlorts, but I
am pretty sure it was not true for the one I was acquainted with.
This was a Air Force radar, not a NASA radar. The NASA Verlorts may
have been a somewhat later version. You can find some more
information by searching on Prelort.

Dan

Dan

Joseph Gwinn wrote:

In article ,
"Michael A. Terrell" wrote:

David Lesher wrote:

writes:

The FAA is planning as decommissioning as much ground equipment as

s/planning as/desperately hoping to/

possible. A primary driver for next-gen is the high cost of operating
and maintaining the ground based primary and secondary radars. A lot
of that stuff is quite old.

As noted by the fact they must buy tubes [yes, those things that glow..]
for some ARSR's [the longer-range radars] from St. Petersburg, and not
the Florida one. (The paperwork for an agency to procure things overseas
is mind-boggling; ISTM this actually has to get Hill approval.)


Which they wouldn't have to do, if our tax laws hadn't put the
domestic OEMs out of business. The cost to tool up for a small
production is high, and the ignorant tax laws killed them on inventory.
They did as much to kill US built electronics, as cheap imports.

Richardson Electronics has picked up most of the residue form domestic
transmitting tube capabilities.


There is indeed a lot of concern over the loss of too much
infrastructure that can track uncooperative targets that can now be
tracked with primary radar, and how many radars are to remain is being
debated.


Output power for modular solid state microwave gear keeps climbing.
If they can build 5 MW UHF TV transmitters, they can build acceptable
solid state modular RADAR gear. The new solid state receivers have a
lot lower noise floor, which reduces the raw RF that has to be
transmitted, as well.

Solid state UHF radar transmitters have been around since the 1980s.

http://www.fas.org/spp/military/program/track/pavepaws.htm

The purchase price is higher than vacuum tube, but the maintenance cost
is lower, especially for systems that must operate 24x7x365 with ~100%
availability.


I was talking about the megawatt variety, like the pair of vacuum
tube Westinghoue 2 MW units tat were at Carin Airfield in the '70s. The
nice thing about a modular transmitter is that some of the outputs can
fail, and the system will still operate.

Cincinnati Electronics was building some solid state replacement
RADAR gear for the military, as drop in replacements in the mid '70s.
They still had a huge WW-II shipboard antenna on the roof of the complex
to test the full RADAR equipment.


--
You can't have a sense of humor, if you have no sense!

Stu Fields wrote:

"Joseph Gwinn" wrote in message
...
In article ,
Stealth Pilot wrote:

On Sat, 06 Jun 2009 01:14:07 -0400, "Michael A. Terrell"
wrote:


Stealth Pilot wrote:

On Thu, 4 Jun 2009 09:22:27 -0500, "Robert Swinney"
wrote:

Excite today carried a piece re. the S. American crash and location
of
planes over the ocean. It
went on to say that radar can't see beyond about 200 miles (let alone
the
fact that bending radar
coverage beyond LOS is pretty remarkable in its own right).

standard radar is line of sight.
we australians have an over the horizon radar which is pretty
remarkable.
I think our guys lead the world with the technology.


the first RADAR systems used in W.W.II was over the horizon, but it
wasn't intended to be. Quite a few 'Ghost fleets' were spotted, and
according to their displays, it should have been plainly visible, when
in fact they were well outside the design range. Then reports came in
of enemy ships being spotted at exactly one or two times the displayed
distance. They finally determined it was due to the low frequency that
the early RADAR systems used.

the frequency may have been right for the conditions but the cause was
ionospheric reflection.

It's not the frequency that causes such ghosts, it's the pulse
repetition frequency that matters.

A pulse radar periodically transmits pulses, listens for echoes between
the transmits, and assumes that received echoes came from the
immediately preceding transmit. Which isn't necessarily true. A large
reflector can have a loud-enough echo from several transmit pulses ago,
making it look like there is a nearby target.

This is called a "second time around" echo (even if its really third
time, et al).

The standard solution is to vary the period between transmit pulses.
Real echoes will not change their apparent range, while N-time-around
echoes will move in predictable ways.

Joe Gwinn

Joe you sound like a Radar Rat. The Nth time around trackers are used in
deep space tracking all the time. Have you been associated with them?
Stu (Radar Rat from NWC and Kwaj)


I built telemetry equipment for deep space tracking at Microdyne. A
customized system (MFR) we built for NOAA allowed them to lock onto
their LEO weather birds a full five minutes over the horizon, and
recover useful data. It is located at Wallops Island.


--
You can't have a sense of humor, if you have no sense!

"Ed Huntress" wrote:


"Bill Noble" wrote in message
...

"John R. Carroll" wrote in message
...

"Brian Lawson" wrote in message
news SNIP
There was a cascade of electrical system failures.
Can't fly one of those things without electricity. They are completely
fly
by wire.

It also looks like it broke up in mid air. There are two debris fields
sixty
miles apart.

JC

Not that is really significant, but it was 60 kilometres (about 36
miles).

No fun, but maybe we should all wait until some decent details are
available to the public.

Eventually there will be a full report but Airbus and Air France have
both released summaries of the telemetry data from the flight.
"Cascading series of electrical system failures" is a direct quote.

I'm also pretty sure the flight recorders will be found. There is no
reason the US couldn't put a couple of subs on this and their passive
sonar would be an excellent tool. The Navy could use it as a practice
excercise and the subs would be relatively unafected by the storms on the
surface. I don't think you get much turbulence at 100 meters and any
search will have to be done deep enough to get the sensor array below any
blocking gradient in either temp. or salinity.

JC


aaah, how deep is the ocean there? Subs do NOT go that deep - do the
math. It may be found via sonar, but retrieval can be quite another
problem - remember the glomar explorer

Based on the depths estimated by the Brazilians (2,000 - 3,000 meters) and
the Americans (possibly 6,000 meters), they'll need a robotic submersible.
There's one that just set a record of nearly 11,000 meters:

http://news.bbc.co.uk/2/hi/science/nature/8080324.stm


http://www.sagemavionics.com/ProdFil...ment/SSFDR.pdf

The FDR is rated for the depth. Assuming this one was used.

WEs

In article ,
"Michael A. Terrell" wrote:

Joseph Gwinn wrote:

In article ,
"Michael A. Terrell" wrote:

David Lesher wrote:

writes:

The FAA is planning as decommissioning as much ground equipment as

s/planning as/desperately hoping to/

possible. A primary driver for next-gen is the high cost of operating
and maintaining the ground based primary and secondary radars. A lot
of that stuff is quite old.

As noted by the fact they must buy tubes [yes, those things that glow..]
for some ARSR's [the longer-range radars] from St. Petersburg, and not
the Florida one. (The paperwork for an agency to procure things overseas
is mind-boggling; ISTM this actually has to get Hill approval.)


Which they wouldn't have to do, if our tax laws hadn't put the
domestic OEMs out of business. The cost to tool up for a small
production is high, and the ignorant tax laws killed them on inventory.
They did as much to kill US built electronics, as cheap imports.

Richardson Electronics has picked up most of the residue form domestic
transmitting tube capabilities.


There is indeed a lot of concern over the loss of too much
infrastructure that can track uncooperative targets that can now be
tracked with primary radar, and how many radars are to remain is being
debated.


Output power for modular solid state microwave gear keeps climbing.
If they can build 5 MW UHF TV transmitters, they can build acceptable
solid state modular RADAR gear. The new solid state receivers have a
lot lower noise floor, which reduces the raw RF that has to be
transmitted, as well.

Solid state UHF radar transmitters have been around since the 1980s.

http://www.fas.org/spp/military/program/track/pavepaws.htm

The purchase price is higher than vacuum tube, but the maintenance cost
is lower, especially for systems that must operate 24x7x365 with ~100%
availability.


I was talking about the megawatt variety, like the pair of vacuum
tube Westinghoue 2 MW units tat were at Carin Airfield in the '70s. The
nice thing about a modular transmitter is that some of the outputs can
fail, and the system will still operate.

Early warning radars do operate at near megawatt RF power levels. The
power level is chosen based on what the radar needs to do, and how
quickly it must do it. There is no technological limit to prevent
megawatt power levels.


Cincinnati Electronics was building some solid state replacement
RADAR gear for the military, as drop in replacements in the mid '70s.
They still had a huge WW-II shipboard antenna on the roof of the complex
to test the full RADAR equipment.

There are still some WW2 radars on older surface ships. Those old
radars were built very well. What eventually kills them is
unavailability of repair parts and/or the oldtimers that know what to do
with those parts.

And those ubiquitous spinning-bar marine radars one sees on all manner
of small boats are a WW2 architecture rendered with solid-state
electronics, except for the magnetron. The main improvements compared
to WW2 designs are the spinning-bar antenna, which has much lower
sidelobes than typical in WW2 designs, and better clutter reduction
algorithms in the receiver. And the use of computer displays, not CRTs
with rotating magnetic fields to yield the PPI display.

Joe Gwinn