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I wouldn't mind working for the company: https://www.harris.com/careers... Looks like cool tech to play with. Too bad they don't have any remote positions :(

The whole purpose of this is to facilitate non-satellite transmission of signals using ionospheric skywave propagation. This is the most common over-the-horizon communication method for HF frequencies (3-30MHz) and below. The military uses HF for tactical communications using radios like the Harris Falcon series manpacks. HF is also used for the Military Auxiliary Radio Service as well as Civil Air Patrol. None of these uses have dependence on satellites which are, in any event, potentially prone to attack, jamming and failure by natural phenomena, and where end user equipment is expensive and potentially tricky to deploy.

In order for HF communications to work effectively and consistently, the sun needs to ionize the atmosphere. It normally goes in the same eleven year cycles, but this year has seen very bad conditions with insufficient consistency to rely on HF. The shortwave and amateur radio community has similarly been affected adversely by this phenomenon. Ionizing the atmosphere through this proposal is one way to make this happen without relying on satellites.

This is a 5ghz band line of sight radio that I have worked with.

This product delivers 108mbps of real bandwidth over a shot that can be up to about 20 miles. The radios can also be meshed, allowing multiple connections to each antenna. It's essentially not all that much different than wifi AP rigged up with a directional antenna. We've seen articles about such shots being extended to the same ranges the RF-7800w achieves. The key issue with such shots is the terrain, of course. Hills and valleys pose problems.

That said, why isn't anyone thinking about this? It would work. True, it wouldn't help with transoceanic shots, but in that case you could consider satellite to carry that kind of traffic. Or just pipe it over the wired Internet using the encryption mechanism of your choice - cheaper and easier. Use the sats as a backup to that in the event of government interference.

Since this is Slashdot, I'll share some details on the problem of measuring loudness.

Loudness is difficult to measure objectively, because loudness is what a human experiences when listening to audio. Intensity, on the other hand, is easy to measure; just get a sound level meter.

Why is loudness different than intensity? Because the human auditory system contains a natural filterbank that divides incoming audio up into multiple bands, and then applies an exponential scaling function to each band. Old books and papers call these bands critical bands; I think the more modern concept is ERBs.

For sounds that hit only one band, such as a pure sine tone, the intensity of the sound is a good approximation of loudness. But sounds that hit multiple bands scale roughly linearly in the number of bands hit. I'll give an example.

If you generate a pure sine tone at power level X, and then generate two sine tones each at power level X/2, then the measured intensity will be identical. However, if the two sine tones are in different bands, the loudness will be nearly double.

So, as a rule of thumb, the more frequency bands a given sound hits, the louder it is at any given power level. Something that sounds like white noise will be louder than something that sounds like a clear bell tone or a single flute note.

The people who make commercials know how to game the system. I'm pretty sure that there were already limits on measured intensity of commercials, but that wasn't enough to solve the problem.

Imagine you are driving along, listening to a radio show. Maybe talk radio, maybe NPR, whatever. You have the "volume control" knob on your car radio set to a comfortable listening level. The radio show only has audio at typical human speech frequencies, and isn't trying to sound loud. Now comes the commercial, which smears its audio all over the spectrum; it puts processing on the voice, with reverb and stuff. "Sunday Sunday Sunday-y-y-y!!!! M-m-monster truck demolition derby!!!" or whatever. It's not your imagination, it really is louder. But a sound level meter might say it's the same as the radio show content, or only slightly higher intensity level.

The company for which I work (DTS) has a solution to the problem called "Neural Loudness Control", and there is a white paper available that really goes into detail about this stuff, so you don't need to stop with my lame explanation. NLC has a full "loudness model" that approximates the human auditory system when computing a loudness metric; but it also can operate in a mode that follows the new standard.

Also, here's a PowerPoint presentation by JJ Johnston about loudness vs. intensity.

So the new standard, 1770, is a pretty easy-to-calculate approximation of loudness. You apply two filters: one that simulates the transfer function of an average human head, and the "RLB weighting curve"; then compute mean-square energy on the result. This is simple enough that nobody really has an excuse in the 21st Century that it would be hard to comply.

I'm a little worried that it is too simple, and there might be ways to trick it. For example, it doesn't seem to handle audio that is smeared across multiple bands to make it sound louder. But I'm not actually working in the area of loudness measurement, and from what I've heard, 1770 works okay for most stuff. It's better than no standard.

And on the gripping hand, 1770 is the law now.

steveha

"You would definitely give a fuck if your batteries ran out on an excursion and you didn't have any way to charge your current one.

You'd give a big, big fuck."

Not at all. See, we don't rely on cellular phones to coordinate things out in the field. That's why we carry things like the PRC-117 or PRC-152 which can last for days and days out in the field. Those are the main forms of communication. When a patrol is done, the last thing we want to do if fuck around with a phone after spending 30 minutes clearing COMSEC and doing radio checks for the next shift. We just want to text loved ones, check email and relax. So no, whether it's a FOSS phone, open for development or whatever - no one cares. Just make it easy to use.

I have no idea what the real efficiency of a TV transmitter is, but if it were 80% input to ERP you get about 4.5 GW of energy used to keep running ATV.

Given that a TV transmitter is mostly just a huge power amplifier, and in my experience most of the higher powered ones contain at least a couple of tubes*, I'd be surprised if the efficiency got over 50%
As a matter of fact, it looks like it's lower than that. Take a look and do your own math.

* Why tubes in this day and age?
They are a proven reliable way of amplifying up to 100s of kilowatts. Transistor amplifiers get very complex even as low as 10KW (the biggest solid state transmitter I've personally worked on). And when they fail it usually takes out dozens, if not hundreds of components. Replacing a pair of final amplifier tubes, and maybe a capacitor after a lightning strike can get you back on the air in an hour or 2.

"Harris is committed to assisting the U.S. Census Bureau in meeting its current and future strategic goals of providing Census-related statistics with increased accuracy at a reduced cost."

From harris.com, specifically here:
http://www.govcomm.harris.com/solutions/marketindex/segment.asp?source=market&mkt=Database+and+Information+Systems+Integration&market_id=99&segment_id=68

http://www.rfcomm.harris.com/products/embeddable-security/SecNet54_11_Brochure.pdf

There's a tendency in the RF world to run everything through BNC connectors, whether you need to or not. Signal generators and scopes usually come with BNC connectors, so if you have those, you tend to have lots of BNC-BNC cables around the bench. Plus the little drawer of T-connectors, angle connectors, and adapters. Hence its popularity in the ham, broadcast, and scientific instrument worlds.

The main problem with RCA connectors is that they bend and become loose as they wear out. That's why they're avoided in PA gear. XLR connectors self-align better and latch into place.

Actually, I do servomotor control, which has most of the problems of audio but with bigger currents. Keeping the huge chopped motor currents from inducing noise into nearby analog sensors is a major headache. But with extra capacitors and inductors, it's a solveable problem.

In any case, without a scope you can't do anything but guess.

The ARRL Handbook is a good source for info about power supply filtering.

Solutions exist to implement secure WiFi, but it comes with a cost.

Harris makes an encrypted PCMCIA 802.11b based card that has high grade encryption built in. It certainly makes the system impossible to get into, but they're far from cheap ($2k+).

Product: SecNet11

In the end, a lot of the exploitable networks comes from either poor management, lack of information or lack of control within government areas.

I work for a government client who's invested a sizeable chunk of change in Harris Stat Scanner They evaluated a number of products, including some leading open source tools like nessus. Their bottom line is that Stat makes the job relatively easy for a largely Windows shop (that is, if you have admin rights to all the boxes, turn on remote registry editing, kill all firewalls/IDSes, etc. - leaving you wide open for the duration of the testing!) to perform a multitude of tests and to install patches on the fly. Reporting is centralized, easy to read, and fairly comprehensive. It works on a fairly heterogeneous network as well, covering Macs, *x boxes, Cisco routers, HP printers, etc. Updates are frequent and easy to apply (basically a reinstall of the product). Most of the folks that will run this product for this client are computer professionals, but few are truly security professionals. This tool makes it almost point-and-shoot simple to understand what's going on and provides the Windows administrators an easy way to get "caught up" on patches they may have missed.

The system that failed at the Los Angeles ARTCC (Air Route Traffic Control Center) is known as the VSCS (Voice Switching Control System). The backup system is known as VTABS (VSCS Training And Backup Switch). The system was installed to replace the aging WECO (Western Electric Company) system, basically a hard-wired system. If one line went down, there were others to take its place. I knew that it would only be a matter of time before a failure in the VSCS system would take down all of our communications, not just ground-to-air, but ground-to-ground as well.

Why didn't the backup system work? Well, the rumor mill has it that VTABS was not properly configured such that when VSCS failed, the frequencies and the lines each controller needs at his particular sector were not available in VTABS. If this was the case, it sounds as if someone in automation wasn't doing his job.

I know that one of the worst scenarios for a controller is to lose his ability to communicate. He can no longer control.

Here's some more info if you're interested . . .

http://www.harris.com/view_pressrelease.asp?act=lo okup&pr_id=78

According to this press release, VSCS offers "an operational availability of 0.9999999."

Someone check my math, but that appears to come out as 3.16 seconds annually, so their 3-hour outage burned up all their allowed downtime for the next 3,422 years.

So it should be quite safe to fly now, statistically speaking.

http://www.harris.com/view_pressrelease.asp?act=lo okup&pr_id=77 Wierd reloading link from the slashdot article text! now3djp

From Harris.com
The system offers unprecedented voice quality, touch-screen technology, dynamic reconfiguration capabilities to meet changing needs, and an operational availability of 0.9999999.

Less than a one percent uptime!?!?! No wonder the thing crashed, it suppose to do that, ALL THE TIME! Bill Gates must be proud.

Yes. The Harris company has produced a WiFi network that is capable of carrying Top Secret data. You need a waiver from an appropriate authority to even get this gear, and you'd best be government.

That said, they aren't talking about deploying one here. This is commercial off the shelf equipment they are talking about in the article. Grossly insecure.

In Iraq, this might work. Good line of sight and all. In Afghanistan - listen, i've seen pictures people brought back from Afghanistan in the last 2 years. It looks like Mordor with the high black mountains surrounding you. Line of sight is a big issue. IOW, this is a half baked scheme for Afghanistan.

There are issues here that I can't discuss regarding the lack of bandwidth available to the deployed personnel except to say that the DoD is seriously delinquent in lofting more comsats for itself.

Before Harris sold it to JetBlue, they developed LiveTV, a system to bring DirecTV to airliners in-flight. The receiver includes a phased array antenna that scans in elevation while sitting on a gimble that allows the beam to be scanned in azimuth.

Phased arrays use lots of power, but that's because each antenna element in the array requires its own amplifier(s) and phase shifter (or time delay unit). Fortunately, those amplifiers cam be much smaller than the monolithic amplifier required to drive a dish (since the signals from each amplifier in the array are summed together).

Those of us who are serious internet broadcasters have quite good uptime. And the downtime we have is easily fixed by spending a little extra money - like having backup playback workstations and using T1s instead of DSL to feed our stream repeaters.

For example, SomaFM runs several of our channels with OtsDJ, an inexpensive but quite capable and professional broadcast playback and stream encoding solution. These instances often have uptime of 60-90 days between restarts, so reliability there is not a problem.

The majority of our downtime comes from the SDSL line that we use to feed the stream repeaters from our studio. If we spent $1500 a month more and put a pair of T1s in a failover config. The rest of our outages come from ISP peering problems, where one of our stream repeaters is seeing a lot of packet loss from it's feeder.

We have UPS power that will run the machines and network at the studio for over an hour, and for $5000 could put in a generator with auto start and a auto transfer switch.

As far as getting the audio back to the Sat providers head end, we could do one of several things: use a Harris Intraplex and a frame relay circuit or just install one of their encoders here connected by an ISDN or fractional T1 frame relay private network. (Most sat channels are 80kb/sec or less,)

It's not rocket science to make an "internet class" radio station as reliable as a commercial over the air station.

-rusty/somafm

You are right, the accuracy stinks. So congress allocated some cash for Census to improve the data. My company won the contract. Read the press release here.
My job is to compare the TIGER maps to locally collected GIS data as well as satellite/aerial images and make corrections as necessary.

"In a lab maybe, but it's still radio."

• When they offered it, Sprint Broadband Direct was much faster than that, on the order of megabits per second.
• Harris Microwave has theier Constellation system can work up to 155 Mb/sec.
• Here's a homebrew 10 Mb/sec microwave system

"In a lab maybe, but it's still radio."

• When they offered it, Sprint Broadband Direct was much faster than that, on the order of megabits per second.
• Harris Microwave has theier Constellation system can work up to 155 Mb/sec.
• Here's a homebrew 10 Mb/sec microwave system

You say "Harris-made" like it's a bad thing :) I happen to work there...

Digital beamforming != Software Defined Radio.
Electronically Steered Phased Array != discrimination between two frequency-adjacent or -overlapping signals.

Remember- for digital beamforming you're not looking at a single signal at whatever the CW frequency is, you're looking at (# elements) signals: one from each of the antenna elements in the array. That means that for a 64-element array 1 MHz AM array (neglecting the fact that it would be HUGE!) would have only 7 instructions per RF cycle (per antenna element). Is that a useful number? (I don't know; I've never done DSP programming.)

Nobody wants a ESPA at those low frequencies; it's been at microwave and millimeter wave frequencies that people have wanted them: Live TV for instance. Comm on the move(search for Harris) for another.

Let me get you started in the right direction:

You don't need to "buy the rights to rebroadcast the songs from the record companies, song writers, and publishers". You merely need to pay royalties for the public performances of copyrighted compositions to ASCAP, BMI and possibly SESAC. The total of all these will be around 5-6% of your stations gross revenue.

Copyright law specifically exempts FCC-licensed radio stations from any fees for public performance of the "Sound Recording" (that is, the copyrights owned by the record companies).

As for the power you will need to cover a decent sized metro area - you sure don't need 50-100,000 watts. The FCC breaks the license classes down into 3 main groups, Class A, B and C. Class A are typically around 5kw, Class B, 50kw, and Class C, 100kw. But an important distinction here is that these amounts are not transmitter power, but ERP (effective radiated power). Also, depending upon your transmitter's HAAT (Height above average terrain), you may be authorized for a lower power than the class of license's maximum.

You would be surprised how well 1000 watts ERP on a hill into a good circular-polarized antenna system will cover a metro area. In fact, in Los Angeles, one station transmits a mere 600 watts from Mt. Wilson and covers all of the greater Los Angeles metro area. In their case, it's the height that gives them the coverage, not so much the power.

You can learn more about station coverage contours, power and classes from the FCC.

But before you get into all that, you should read the FCC's Broadcast Station Application Process. Did I forget to mention that you need to either buy an existing license or apply for a new one? And before you can even apply for a new license, you'll need to prove that you have the financial resources to complete the station and do a technical feasibility study - usually a spacing study for commercial FM (to make sure you can fit your station into the band without causing interference to existing stations) or a Interference study for noncommercial/educational stations (in the 88.1-91.9 part of the band. You can't do these yourself, you'll need to hire a company who specializes in this and has access to the FCCs databases. Dataworld is a company that has been doing this for over 25 years.

Before you get started on this, you should do a lot of background reading. An FCC licensed station is not a toy o hobby and there is a tremendous amount of responsibility that comes with it. Fortunately, the FCC has a How to Apply for a Broadcast Station section of their site. Unfortunately, it starts off like this:

Potential applicants for radio and television services should be aware that frequencies for these services are always in heavy demand. For example, the Commission received approximately 30,000 inquiries from persons seeking to start radio broadcast stations last year. Where broadcast frequencies remain available, competing applications are routinely received. Thus, you are cautioned at the outset that the filing of an application does not guarantee that you will receive a broadcast station construction permit. You should also be aware that in many areas of the country, no frequencies may be available on which a new station could commence operating without causing interference to existing stations, which would violate FCC rules.

There are so many other things you're going to have to think about before you apply for a license as well.

• Is the transmitter going to be at the same location as the studio? If not, how are you going to get the signal to the transmitter? (A STL, microwave band studio transmitter link, is a popular way - but you'll need a license for this too...
• If your studio is going to be co-located with your transmitter, you have to pay a lot of concern to keeping RF interference from your transmiter out of your audio signals. This means 600 ohm balanced audio feeds, not the typical RCA or miniplug consumer unbalanced audio lines.
• The minimum hardware you'll need is a transmitter/exciter, audio processor/stereo generator, antenna system, tower, Emergency alert system hardware, etc.
• You may be required to provide the FCC with a "Proof of Performance" - going out with a GPS and signal strenght meter, and proving that your transmitter and antenna system are operating as planned.
• You'll also need some monitoring instruments to make sure that your station isn't putting out too much power, or transmitting with too high of deviation (overmodulation).
• Last you'll need a way to feed audio. A Linux box playing MP3s probably won't cut it. At a minimum, you need to schedule the "legal IDs" at the top of the hour. There are commercial broadcast automation packages out there that cost under $2000, alas they all run under Windoze. There is no reason you couldn't write one for Linux.
• And I think you need at least a small mixer and a microphone so that when you need to, you can address the audience. (And aternatively play music when you're doing upgrades to the automation system.)

I suggest you subscribe or read online Radio Shopper, a radio tech centric newsletter that also covers things that small operators need to do to fufill their oblications to the FCC and the community. And of corse, it's a great place to find used transmitters and antenna systems.

Some places to get a feel for the prices of this equipment are Broadcast Supply Worldwide and Harris Broadcast. If you are on a budget and need used equipment, Mooretronix is a great place to start.

Here's a great pictorial of the installation of a new FM antenna system and 60kw transmitter for KPFK in Los Angeles. Just to give you an idea of what is required. KPFK is a non-profit.

I also suggest reading Bob Gonsett's CGC Communicator, a really great technical newsletter for broadcasters in the Southern California area. There are hundreds of his past newsletters online, and you can read about the saga of new stations in SoCal, as well as issues with construction permits (station upgrades). Lots of good info here.

I hope this has helped give you some good background on what all is involved in starting a radio station. I've worked at a couple small commercial broadcast stations in the past. I assisted in some upgrades to the transmitters and antenna systems, so I got to see all that was involved with just the construction permit with the FCC. I even got to assist in a proof of performance once, back in the days before GPS. We had to do it all using topo and street maps.

So don't give up hope - you CAN start your own radio station. But it's really hard to do with just one person. And it will take a bunch of money. Get a critical mass of people together in your town, form a non-profit, there is a really good chance that it you're not in one of the top 100 radio markets that you can get a license and start a station.

I encourage you to try!

--rusty

Apparently you have to wear camouflage to use these cards. I suppose that provides added security.

It's way overkill for your small business, and I doubt you could afford it, but Harris has recently started taking orders for it's new 802.11b wireless network cards and access points They're Type 1 encryption, as opposed to FIPS category devices which are Type 3. FIPS level security is for sensitive, but unclassified information, meaning it would be bad, but not devestating if this info was cracked. Type 1 devices are used to protect Classified information, seriously bad juju could happen if the wrong people get this info.

Not only that, they have a price-point about half that of previous Type 1 encryption devices, about 2700 per node as opposed to about 5k per node.

Hope this helps, they have a nice datasheet and brief on the site.

Steven

Water Cooled Tubes are in many high power modern RF transmitters ... I have yet to see a solid state high power AM transmitter. Semiconductors can just not take the power load.

Water cooled tubes are designed and built to be water cooled. When I did college radio we had an Old Harris transmitter that use to melt the tubes on us (as in the tube would come out as a glob of glass). We replaced it with a prototype first generation Harris Solid State FM transmitter ... and was in 1995.

Check out Harris for more information on high end RF systems. Hmmm... looks like they do have solid state high power AM transmitters now ... amazing

The US constitution specifies that US Citizens must be enumerated within every ten year period. Nowhere does the constitution authorize such detailed data collection, nor is it "necessary and proper."

This update program is called MAF/TIGER. An optional feature request in this update would involve merging these GPS coordinates with something like the Realsite program. This would give a textured 3D model that is geospatially accurate to within 1 meter, based off of aerial, satellite and hand held photography.

Thinking in paranoid mode I can't help but think of government surveillance via satellite and robot and cruise missiles targeting specific GPS coordinates.

I'm not seriously worried about anything in particular, but it's the abuse that I cannot foresee that truly worries me. As I cannot conceive of any benefit that this program would bring to the average citizen I have to ask, why are we doing it?

We ended up staying in the Windows realm (for the reason you gave). I wish we had chosen AudioVault or Scott's Studio, but we went with CCC (forgot the meaning) and had trouble after failure after disappointment. (BTW, we continued to use SAW 32 for our production work. Still do, as a matter of fact.)

I've watched Freshmeat for this type of thing for some time but haven't seen anything compelling (except some possible audio editing solutions).

It sure would be nice to use OS/FSF software for non-profit operations!
--

The AD2000 was water- and sand-proof and had a two-week battery life (better than Apple's beasties). Imagine a Newton 2000 that could be dropped onto concrete with no ill effects, and that's what the AD2000 was. The AD2000 was aimed at the telcom field-service people, wasn't offered to the general public and was *expensive*.

I briefly thought about getting one (hey, check my User Page for the reason why), but their cost and bulk made them unattractive, even if it did say "Harris" on it.

Looking through the external Harris pages I can't find much on it; perhaps it's been dropped. I don't work in that area, so I never dealt with it.

The AD2000 was water- and sand-proof and had a two-week battery life (better than Apple's beasties). Imagine a Newton 2000 that could be dropped onto concrete with no ill effects, and that's what the AD2000 was. The AD2000 was aimed at the telcom field-service people, wasn't offered to the general public and was *expensive*.

I briefly thought about getting one (hey, check my User Page for the reason why), but their cost and bulk made them unattractive, even if it did say "Harris" on it.

Looking through the external Harris pages I can't find much on it; perhaps it's been dropped. I don't work in that area, so I never dealt with it.

This is just what happened to Harris last week!

I suppose that, just as last week, some AC is going to shoot off their keyboard, saying how they'd not want to do business with Nike due to their obvious ineptitude, letting their domain get hijacked through inadequate security and all.

{/rant}

NSI has obviously got to go. Their services are vital; I'll admit that. Their execution is just awful. As much as people talk about the 'net as free, much of what the internet is to the average joe is handed down from ivory towers like NSI.

Domain names aren't necessary, but they sure do make life a lot more fun and user-friendly. NSI provides a service to the community, but they need to have some kind of accountability.

If NSI is truly a private organization, the most direct way to institute that accountability is to hit them where it hurts-- their pocketbook. Perhaps Nike, Harris, and all the other domain registrants that have had their domains hijacked because NSI wouldn't follow their own security policies should file a class action suit against them, and shake them down a little

NSI will now join a growing list of organizations that have gotta go:

• Internal Revenue Service
• Department of Education
• Environmental Protection Agency
• Department of Energy (give good stuff back to DOD first!)

Jeff