On Apr 9, 10:34 am, krackula <<krack...@i.am>> wrote:

snipped for  brevity ...........

The 1400 or so band use to be federal, but I think as a primary user.
Those 2G and 5G bands are mighty crowded, especially 2Ghz.

with the government's - military's  current spread spectrum digital
communications  and data systems , " operational crowding "
 of freqs isn't generally experienced.

as with any spread spectrum radio system many 1000s ( at least , and
some say many  10s of 1000s  )   of simultaneous users can inhabit the
same range of freqs  ( these are also  freq hopping ) without even
knowing that each other are present   that , plus civilian users of
the same freqs can't  ( generally ,  heard  by  civilian fm radio and
wi-fi  users  as a light background hiss )  even detect  their
presence.  that was a major incentive for changing over to spread
spectrum back 15 years ago.

  in spite of what people claim,  these systems are NOT totally
eavesdropping proof .........  while yes  we cannot decode the digital
pin modulated stream ( or even keep up with the channel hopping ) ,
ANY surplus '70s - '80s  Watkins- Johnson eavesdropping receiver (
commonly found on ebay ) and ANY high end HP spectrum analyzer (
connected to an outside antenna with a Stridsberg  hi I point preamp )
can " see " these transmitters easy as pie !  simply knowing they are
nearby and how many of them there are can be very useful information
at times. ( a good incentive to switch to UWB which cannot be " seen "
by anything yet  ).
 any major metro area or military base area has a number of these  ss
frequency hopping  trunking repeaters installed , most of them there
since the mid '90s or earlier.  they are easy to spot with the above
equipment.  ( heard in an ordinary scanner as nothing more than an
occasional  momentary carrier on a channel you are tuned to ) .
 here where I  am, there are more than 6 of them , but mid sized
cities like Cincinnati , and Cleveland   have 2 - 3 ea. ,  Fresno  2 ,
Sacramento 2 , but S.F. - Bay Area  has 9  of them .

military spread spectrum radios have a control channel that assigns
their receive and transmit  spreader codes on the fly ........ this
controlling  the number of other stations they can hear and / or
communicate with .......  crowding on their own systems , even in a
military battle field situation ( especially ) doesn't happen. these
same stations can't even hear or detect civilian types of
communications.  spread spectrum  IS  rumored to be prone to
jamming under some conditions ..... resulting in a reduction of
operational range ....... a major reason why most military SS units
are higher powered  than you'd expect.

http://en.wikipedia.org/wiki/Spread_spectrum

http://www.jiwire.com/glossary.htm?id=151

at 2 gigs , wi-fi is generally also spread spectrum type emissions
.....  it's why many 1000s of wi-fi users in large high rise office
buildings in large congested downtown metro areas can use the same
small range of channels and still not interfere with each other to any
large extent.   for the same reason they can't hear each other , they
can't hear the mil-coms on the same range of freqs !  it's the #1
reason wi-fi works ( besides being broadband ha hah ah ) .

UWB wi-fi will soon totally replace  SS wi-fi because it is 100  times
better (  for the reasons mentioned above ) than spread spectrum.
uwb is already well on it's way having replaced wi-fi in many
countries !

civilian uwb  wi-fi implemented back in 2005 .......http://news.bbc.co.uk/1/hi/technology/4317511.stm
government - mil uwb WAY before that ......... they had it
first.

There used to be an experimental license for Lockheed at Nellis and a
few other bases. I'll have to dig for it since it is no longer on the
FCC database.

in answer to an interesting email ...........

yep you're right about that , but it's not true that SS  radio systems
have  rendered  eavesdropping  totally useless ...... far from it .

for the first part of your note ........

well ......... my experience with the unified  systems ended back in
the mid '90  and since the current government - military unified
commo system  is 15 years old now ( and due for  pending
major upgrades incorporating more RFID and UWB gear  )
I only know about it  mostly in a historical sense and  ( as far as I
know  ) all  of it is generally still classified  on some level .
( the reason it's presence in aircraft is never mentioned tho most
modern mil aircraft have them ! ) .

tho digital   manpacks , mil comms and gov comms tried many different
types of  digital commo units through out the '70s - '80s , the  ( at
the time ) new unified  communications systems were, formally
deployed in the field  in   early '90 and were battle  tested (
successfully ) in the  1st Gulf War .   this system was intended to
eliminate , forever ,  ALL of the problems caused by all the differing
previously issued com equipment  ( that couldn't talk to each other )
and pave the way for  ALL the future radio systems to follow, namely
the data and video link  systems and the 1 gig and up systems to be
deployed !  the modern battle field is a wonder of digital
communications equipment .....an enormous  maze of digital data ,
video and com equipment and  requires a highly  integrated radio
system to manage it all properly.

  original equipment of the integrated system used  data channel info
for  resources allocation and field positioning - locating purposes
( like GPS does nowadays ) .
as time passed and equipment increased in complexity and capability,
the data channels became clogged with traffic and problems (
especially in battle field conditions )  ensued.   more recent shifts
( early  21 century , the government had it WAY before the civilians )
towards incorporating  ( new technology ) wider band width UWB
equipment and especially the spider web of  wideband - RFID
illuminator satellite, and GPS  systems ...... have solved the clogged
data channel problems and added new features of surprising abilities
and capabilities ( can't say more about this  ) .   absolutely
everything out there in government and milcoms has digital com  and /
or  a digital datastream associated with it now ! from manpacks , HTs,
aircraft, mobile command centers, satellites  and command center bases
are a wonder of  modern " UNIFIED " digital communications .

sooooooooooooooo ..... all this being the case , what about us
eavesdroppers and are we out of business now ????

noooooooooooooooo ....... not at all  my friend , not at all ! and why
?? ..... well it's because there are a LOT of circumstances where this
equipment has to  " go out of the system " to talk to  local coms -
civilian coms as well.  while the government might have all this nifty
equipment deployed , a LOT of the government and civilian world is
still using old  ( 40 - 50 years < nbfm >  or more , like civilian
aircraft radios < am >  which style is 60 - 70 years old  ) radio
systems and the unified system was designed to work with ALL
other  standard radio systems.

it's like the example of a local police radio system upgrade ! they
might go to an encrypted local trunking repeater and you might not be
able to hear them there , BUT ,  they also usually have to have a port
- channel that is NOT encrypted or trunked to still communicate with
all the older  regional radios that have NOT upgraded yet !
( this especially in an local or regional  emergency situation  )
a person can listen to the  unscrambled , non trunked port channel and
still hear much of the interesting stuff that is happening. while it's
true you might not get all the goodies this way, still it's not " game
over " by any means !  one can still hear great stuff if you know
where to listen.

mil air coms is  in " exactly " the same boat.  in the aircraft world
in particular ,  a LOT of the equipment is still using the old a.m.
radio communications modulation mode ( a mode 70 years or more old ha
ha ha)   , in fact nearly all of the civilian world is still using it
!   military planes have to share the air with civilian planes and
because of that they also have to be able to talk to them as well.

that and lots of times mil air coms are left on the a.m. modes for
training and testing so that civilian  users can know that they are
nearby and activity is taking place. even in time of war ( the gulf
wars  being a good example ) , " some " talk could be heard on
civilian channels. granted the VAST majority of mil and mil air coms
took place on encrypted spread spectrum channels , still there was a
lot of  civilian channel traffic  as well !

it's also interesting to note that mil air coms sometimes take place "
out in the open "  intentionally to " leak "   information they want
the public to have. rest assured that nowadays  if  government - mil
com users  want gov coms , mil coms and mil air coms to be secure,
they have all the equipment in place to make it so , any time they
want.  ( just like the civilian example of ALL  police department
mdt style communications must now be digital and encrypted by federal
mandate )

rest assured too that when training like red flag is taking place ,
ALL the unified mil com equipment is in place  ( some of it awkwardly
grafted on to planes that didn't have it, as seen  in many of miso's
photos )   and  extensively used ...... keeping the  voice coms and
data coms totally secured , whenever they want ........  as  would be
necessary to replicate the actual battlefield conditions the pilots
could  encounter as well.

hope you brought your lunch to read this diatribe ........ haha haha
ah

Actually, the hoppers are often not working. That is why you can hear
so much radio traffic at Red Flag. The last flag only had Have Quick
working about 20% of the time. Timber was less of a problem.

I have a Microtel receiver, so I have a panoramic frequency display.
The trouble is mine is so old I don't want to take it on the road. It
is the model with a mechanical servo to track signals. It uses two
tubes. The 100GHz limit on the dial certainly is cool.

http://www.lazygranch.com/wc9xqe.pdf
This is the experimental license that has left the website, well, sort
of. I'm working on resurrecting all the transmitter locations. Stuff
doesn't die on the FCC website. It just gets buried. There is a
certain facility in northern California that managed to get their
transmitter info removed from the web, but I found the applications
elsewhere and the frequencies were still good. And when security
spotted me snooping on them, well, I heard my plate go over the
air. ;-)