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Effective Communication

Communications men, US Navy WWII Pacific Theater

Communications men, US Navy WWII Pacific Theater

In almost every broadcast company I have ever worked for, there is always some communications dysfunction between management and the technical staff. It is perhaps, inevitable given the different cultures. Most managers come from a sales background, where everything is negotiable. The engineering field is fixed in the physical world, where everything has two states; right/wrong, on/off, true/false, functional/non-functional, etc.  Try to negotiate with a non-functional transmitter, let me know how that works.

Engineering eggheads often couch their conversations in technical terms which tend to confuse the uninitiated.  While those terms are technically correct, if I said “Радио генератор инвалида.”  You’d say “Huh?” and rightly so.   If the receiving  party does not understand the terms used, it is ineffective communication.

The other mistake I often see, which irritates me beyond reason, is long rambling e-mails or other documents that fail to come to the point, directly or otherwise.  Time is a precious commodity, waisting other people’s time with long needless diatribes is ineffective communications.  Likely, the recipient will not read the entire thing anyway.  If a person gains a reputation for generating huge amounts of superfluous verbiage, then it only becomes so much background noise to be filtered out.  When I was in the service, I went to a class called “Message Drafting.”  This was back in the day when everything was sent via radio.  The gist is to get the complete idea across to the recipient with as few words as possible.  Think: “ENEMY ON ISLAND. ISSUE IN DOUBT.”  Clear and concise, six words paints the picture.

The key to effective communications is to know your audience.  If you are writing a white paper for a bunch of MIT graduates, use all the appropriate technical terms.  More often than not, however, as a broadcast engineer, our intended audience is more likely station management and/or ownership.  Their backgrounds may be sales and finance.

In order to get those technical ideas into the heads that matter, a good method is to use the lowest common denominator.  If the general manager is a former used car salesman, car analogies might work.  The transmitter has 200,000 miles on it, the tower is rusting out like a ’72 Pinto, and so on.  Almost anything at a transmitter site can be compared to a vehicle in some way.  Find out what the manager’s background is then figure out what language he or she speaks and use it.  You may say, “But he is the manager, it is up to him (or her) to understand this stuff.”  You are not incorrect, but that is not how the world works.

Secondly, use brevity in communications.  Managers are busy, engineering is but one aspect of the radio station’s operations.  If written, provide a summary first, then expound upon it in follow up paragraphs if required.  If you are in a meeting, give a brief presentation then wait for questions.  Always have a high ballpark figure in mind when the inevitable “How much?” question comes along.

Don’t assume that the manager will follow through with your ideas up the chain of command, always follow up a few days later.  If it is important, continue to ask, in a friendly way, if there is any progress on the issue.

There are so many ways to communicate these days that failure to communicate is almost unfathomable.  One additional thought, if you find yourself out of the loop, find a way to get back in or you’ll find yourself looking for a new job.

AM HD update and other ideas

Looks like the AM HD Radio™ juggernaut continues… To sink under it’s own technical faults that is. According to the list the number of AM stations running IBOC in the US is now down to 233 stations from a high water mark of 290 or so.  That represents a total of  just 4.8% (233 IBOC/4782 Total stations) of all US AM radio stations.  On a related note, Bob Savage of WYSL 1040, Rochester, NY has a good idea:

I’ve always said – if you want to see surprising new life in the AM band, s**t-can the stupid irrelevant NRSC pre-emphasis filter and allow stations to run to 15 kHz during daylight hours and 10 kHz nighttime.  Mandate C-QUAM in all receiver and receiver devices.

It will sound better than HD, be more robust, and cause far fewer problems.  Plus it wouldn’t obsolete a single radio out there, while making a whole bunch of them sound a whole bunch better.

It is so simple in concept, so easy to implement, with almost no expense to AM stations.  Again, Mr. Savage:

Most software-based processors have com ports which can be addressed by a remote control system like Sine Systems, so when the power gets reduced at evening pattern change, the bandpass can be changed at the same time…..vice-versa at sunup.  No biggie.

For older setups a simple outboard relay and rolloff network could accomplish the same thing.  It’s a little more complex but again, not a big deal.

Wow.  Facepalm.

Wish somebody had though of that a few years ago, it might have save several million dollars and we’d have a different AM band today.

There are a few shoe horned AM stations around here that might be adversely effected by 15 KHz daytime bandwidth, but those are few and far between.  By and large, most stations are spaced correctly where this could really work and work well.  It certainly would not generate the chaos that AM HD Radio™ has.

Top ten free andriod apps that every broadcast engineer needs

I have been using my Android phone for about 7 months now.  During that period of time, I have found many useful applications and some not so useful ones.  This is a great time saver for technical people.  This list is by no means complete, I did not include any manufacturing or supplier applications like Digikey.  These are tools for the most part.  They are the applications that I have found that have made my life easier.  I focused on the free applications rather than endorse any paid applications.

This is a list of apps that I found most useful for radio engineering:

  1. VNC Android. Great remote computer control application that will work with almost any version of VNC server.   For logging into servers and workstations to fix things remotely, great time/sleep/gas saver.
  2. ElectroDroid. App has many electrical engineering calculators; Reactance, voltage divider, resistor ratio, resistor series-parallel, capacitor charge, ohm’s law, resistor of LED, LM317, voltage drop, and battery life.  Also includes resistor color codes, SMD resistor color codes, inductor color codes, various pin outs, wire ampacity tables.
  3. Metrics Converter.  A general units converter for metric to standard measurements.
  4. WiFi Analyzer.  Cool application that has a WiFi spectrum analyzer, shows all WiFi channels, signal strengths and router name.  Can show an * for open networks.
  5. Kreac Calculator. A full featured scentific calculator, includes all trig functions, roots, pi, log, e, ln, 1/x, etc.  Very handy for some quick figuring on the fly.
  6. RecForge audio recorder.  Can record .wav, .mp3 or .ogg in 8,11,22 or 44 KHz mono or stereo.  The audio can be stored in different folders and emailed.  Great for quick recordings that can be emailed back to the news room or studio.  Sound quality is as good as the microphone on the device.  My HTC mic sounds pretty good.
  7. Google maps.  Great for finding things, satellite views, etc. Use Itouchmap via web browser to find coordinates of a location by taping a map.
  8. Flashlight.  Self explanatory, three levels, good for emergency use, but I’d not use it regularly as a work light, it runs the battery down too quickly.
  9. Audalyzer.  Small audio analyzer that works pretty well.  If something more is needed, professional versions are available for around $5.00.
  10. Radar now.  Uses GPS location to generate moving weather radar picture.  This has come in handy when doing tower work during thunderstorm season.  Good for pulling tower crews or reassuring tower crews as needed.

Those are the free apps, there are many, many more available from the app store.  As far as iPhone apps go, I just don’t know because I have never owned one.

The LED work light

As is often the case when doing studio wiring, some type of work light is needed, especially when working inside studio furniture.  Having a good work light makes it easier to see wire colors and usually means fewer mistakes, thus the installation work goes faster.  I remember being questioned by the CFO of the last company I worked for when making purchases like this in the past:

CFO “Fifty nine dollars for a work light?  Did we really need that?”

Myself: “Yes.”

CFO:

Myself:

CFO: “Uh, care to expound on that at all?”

Myself: “No.”

The studio I was working in yesterday didn’t even have its overhead lights installed yet, so work lights were a must.

Normally, some type of halogen or incandescent light is used.  The downside to these types of work lights is excess heat, especially inside studio furniture cabinets.  I have often felt like the side of my face was getting sun burned when working in close quarters with one of these units.

Fortunately, we bought this light:

LED work light

LED work light

LED work light

LED work light

Say or think what you will about global warming, environmentalists and so on.  The high efficiency LED light works very well and kept me from boiling when punching down wires.  As with most LED lights, it has a high blue content, which most people find a little harsh.  I like this light temperature for detail wiring work.  It has an internal battery plus a plug in wall wart for recharging and using as a wired light.

Not that I have any loyalty to that particular brand, but the light worked very well.  I am not sure how durable it is, it seems a little light duty.  That being said, I’d recommend it.

Milwaukee's oldest radio station

WISN 1130 AM has been on the air since 1922, although not always with those call letters.  In an interesting twist, the license was granted to the local newspaper, the Wisconsin News and the Milwaukee School of Engineering.  Initially, both entities were programming the station, however, by about 1925, the newspaper was responsible for programming and the engineering school was responsible for technical operations.

In 1941, the station increased power from 1,000 watts to 5,000 watts and added night time service.  This is a series of pictures from that time period.

WISN night time allocation study

WISN night time allocation study

Back in 1941, night time interference was taken seriously.  The night time allocation study (on 1150 KHz, WISN’s former frequency) includes co-channel stations in the US, Canada, Cuba and Mexico.

WISN night time allocation ma

WISN night time allocation ma

The array consisted of four Blaw-Knox self supporting towers in a rectangle.  Notice the lack of fencing, warning signs and the like around the towers.

WISN antenna array

WISN antenna array

From the front of the transmitter building

WISN transmitter site, 1941

WISN transmitter site, 1941

The site looks well designed, no doubt manned during operation, which at the time would likely be 6 am to midnight except under special circumstances.   Most of these old transmitter sites had full kitchens, bathrooms, and occasionally a bunk room.  The transmitter operators where required to have 1st telephone licenses from the FCC.   There is only one manned transmitter site in the US that I know about; Mount Mansfield, VT.  There, WCAX, WPTZ, WETK, and VPR have their transmitters.

WISN RCA BT-5E transmitter, 1941

WISN RCA BT-5E transmitter, 1941

The WISN RCA BT5E transmitter looks huge for that power level.  Back in the day when AM was king, these units were designed to stay on the air, no matter what.  I don’t know too much about this model transmitter, but if it is like other RCA/GE models from the same era, it has redundant everything.

RCA AM antenna monitor

RCA AM antenna monitor

Old school antenna monitor.  I have never seen one of these in operation, however, as I understand it, the scope was used to compare the phase relationship of each tower against the reference tower.

These pictures are of the WISN 1150 array was it was in 1941.  Since then, the station has changed frequencies to 1130 KHz and increased power to 50,000 watts daytime/10,000 watts night time.  The daytime array consists of six towers and the night time array has nine towers, all of which are 90 degrees.

Special thanks to John A. for sending these pictures along.

Solar flare may disrupt radio systems

Update: What?  Nothing Happened!  Something I think any radio engineer can appreciate, the incoming magnetic field from the flare was not polarized for maximum effect.  According to NOAA Space Weather Prediction Center, the incoming particles were parallel to the earth’s magnetic field, and thus blocked.  In order for storms to have major effects, they need to be cross polarized with the earth’s magnetic field.  Learn something new everyday.

On February 15 at 01:50 UTC, a massive flare erupted from the sun.  Classified as a X2.2 storm, it is the largest since December 2006.  The 2006 storm disrupted GPS, some satellite signals and caused 950 mHz STLs to burp occasionally.  With all of the cellphone systems synced to GPS, not to mention things like HD Radio exciters, it could be an interesting day.  Or not.  Already, some reports are trickling in from southern China of communications disruptions.

Feb 15 0150 UTC solar flare

Feb 15 0150 UTC solar flare

According to NOAA Space Weather, there is a 45% chance of geomagnetic activity starting on Thursday, February 17th.  It is noted that Geomagnetic storms reaching the G1 level and radio blackouts reaching the R1 level are to be expected.  Mid to high level latitudes may see extensive aurora borealis, which will be visible in spite of the full moon.

Everything we do is destined for one place.

I give you, The Human Ear:

Anatomy of the human ear

Anatomy of the Human Ear, courtesy of Wikipedia

All of the programming elements, all of the engineering equipment and practices, all of the creative process, the music, the talk, the commercials, everything that goes out over the air should reach as many ears as possible.  That is the business of radio.  The quality of the sound and the listening experience is often lost in the process.

Unfortunately, a large segment of the population has been conditioned to accept the relatively low quality of .mp3 and other digital files delivered via computers and smart phones.  There is some hope however; when exposed to good sounding audio, most people respond favorably, or are in fact, amazed that music can sound that good.

There are few fundamentals as important as sounding good.  Buying the latest Frank Foti creation and hitting preset #10 is all well and good, but what is it that you are really doing?

Time was when the FCC required a full audio proof every years.  That meant dragging the audio test equipment out and running a full sweep of tones through the entire transmission system, usually late at night.  It was a great pain, however, it was also a good exercise in basic physics.  Understanding pre-emphasis and de-emphasis curves, how an STL system can add distortion and overshoot, how clean (distortion wise) the output of the console is, how clean the transmitter modulator is, how to correct for base frequency tilt and high frequency ringing, all of those are basic tenants of broadcast engineering.  Mostly today, those things are taken for granted or ignored.

Audio frequency vs. wavelength chart

Audio frequency vs. wavelength chart

Every ear is different and responds to sound slightly differently.  The frequencies and SPL’s given here are averages, some people have hearing that can go far above or below average, however, they are an anomaly.

An understanding audio is a good start.  Audio is also known as sound pressure waves.  A speaker system generates areas or waves of lower and high pressure in the atmosphere.  The size of these waves depends on the frequency of vibration and the energy behind the vibrations.  Like radio, audio travels in a wave outward from it’s source, decreasing in density as a function of area covered.  It is a logarithmic decay.

The human ear is optimized for hearing in the mid range band around 3 KHz, slightly higher for women and lower for men.  This is because the ear canal is a 1/4 wave length resonant at those frequencies.  Mid range is most associated with the human voice and the perceived loudness of program material.

Base frequencies contain a lot of energy due to the longer wave lengths.  This energy is often transmitted into structural members without adding too much to the listening experience due to a sharp roll off starting around 100 Hz.  Too much base energy in radio programming can sap loudness by reducing the midrange and high frequency energy from the modulated product.

High frequencies offer directivity, as in left right stereo separation.  Too much high frequency sounds shrill and can adversely effect female listeners, as they are more sensitive to high end audio because of smaller ear canals and tympanic membranes.

Processing programming material is a highly subjective matter.  I am a minimalist, I think that too much processing is self defeating.  I have listened to a few radio stations that have given me a headache after 10 minutes or so.  Overly processed audio sounds splashy, contrived and fake with unnatural sounds and separation.  A good idea is to understand each station’s processing goals.  A hip-hop or CHR stations obviously is looking for something different than a clasical music station.

For the non-engineer, there are three main effects of processing;  equalization, compression (AKA gain reduction), expansion.  Then there are other things like phase rotation, pre-emphasis or de-emphasis, limiting, clipping and harmonics.

EQ is a matter of taste, although it can be used to overcome some non-uniformity in STL paths.  Compression is a way to bring up quite passages and increase the sound density or loudness.  Multi band compression is all the rage, it allows each of the four bands to react differently to program material, which can really make things sound differently then they were recorded. Miss adjusting a multi band compressor can make audio really sound bad.  Compression is dictated not only by the amount of gain reduction, but also by the ratio, attack and release times.  Limiting is a relative to compression, but acts only on the highest peaks.  A certain amount of limiting is good as it acts to keep programming levels constant.  Clipping is a last resort method for keeping errant peaks from effecting modulations levels.  Expansion is often used on microphones and is a poor substitute for a well built quite studio.  Expansion often adds swishing effects to microphones.

I may break down the effects of compression and EQ in a separate post.  The effects of odd and even order audio harmonics could easily fill a book.

The K9AY receiving loop antenna

Not to take anything away from Gary Breed, K9AY, who makes and sells these things under the corporate name AYTechnologies, I decided to make my own K9AY antenna system and controller.  Basically, after looking at the currently available commercial version, I figured I could make a better unit for less money and be happy.

The basis for the K9AY antenna is that it has a steerable null.  The gain around the antenna is close to unity, except for the terminated side of the loop, which has a deep null.  This can be switched around using a combination of relays that change the loops and termination.  This comes in very handy for MW and SW listening, when co-channel stations can create annoying interference and hetrodynes.  I have had good success pulling many stations out of the muck, especially in the AM band using this antenna.

This antenna requires a good ground to work against.  For optimum installations, I would recommend placing two radials under each side of the loops.  This will keep the ground conductivity below the antenna fairly constant, thus the value of Rterm will remain consistent for each band.

My other idea is to add a preamp right at the antenna to overcome transmission line loss and the loss from a 4 port passive receiver coupler.  Something around 10 dB, low noise (obviously), low parts count and rugged.  I decided that a Norton preamp was a good design, with only one active device, a common 2N5109 BJT.  Most of the time, this preamp is switched off and out of the circuit.  There have been several occasions, however, where an extra 10 dB made the difference between no copy and good copy.

This is the schematic of the relay board and preamp combined:

K9AY antenna controller with preamp

K9AY antenna controller with preamp

The parts list is as follows:

Symbol Part Symbol Part
C1 – C5 Ceramic 0.1 uf capacitor R1 2 Kohm ¼ watt
FB-1 Ferrite bead, Amidon FB-43-101 R2 8.2 Kohm ¼ watt
K1 – K3 Omron G6K-2F-Y small signal relay R3 100 ohm ¼ watt
L1 22 uH ¼ watt R4 51 ohm ¼ watt
L2 100 uH ¼ watt T-1 9:1 balun
Q1 2N5109 w/heat sink T-2 Norton feedback trans

The 2N5109 transistor is a CATV unit and it has a 50 input and output, that reduces the number of impedance transformers required. The value of Rterm is determined by which band one wants to operate on.  I used Omron G6K series low signal relays.  Again, because this is a receive only antenna, those relays will work well.

Terminal board connections, TB1:

Terminal Use
1 SW loop
2 SE loop
3 NW loop
4 NE loop

Wire loops go between Terminals 1-4 and 2-3.

Control terminal board connections, TB2:

Terminal Use
1 Preamp power
2 Rterm
3 Rterm ground
4 Ground
5 Relay 2
6 Relay 3

To create a low noise preamp, I decided to use surface mount devices and to try and make all the traces as close to 50 ohm impedance as possible.  I created this SMT printed circuit board:

SMT K9AY board, not to scale

SMT K9AY board, not to scale

From this, I ordered 6 boards from PCB express:

K9AY PCB

K9AY PCB

This is the board with all passive components installed:

K9AY loop antenna control board partial

K9AY loop antenna control board partial

This is the board completed:

K9AY antenna control board completed

K9AY antenna control board completed

My current K9AY is an amalgamation of parts removed from various equipment.  The relays are large, 12 VDC units which do not have the best contacts.  It works well enough, but I’d love to get one of these units into the control box at the base of the antenna.  Unfortunately, my antenna field is still in about 18 inches of snow, so it will have to wait until some of the snow melts off.

I would position this antenna as far away from transmit antennas as possible to avoid overloading the preamp and or causing problems with the switching relays.  For the average amateur set up, 75 to 100 feet separation should be more than enough.

WEBE WICC studio build out

You know those fancy new facilities pictures with the accompanying article you can normally find in the trades?  The article usually expounds on how this guy made the decisions on purchase then these guys worked hard and pulled it all together.  Here is the works hard and pulling it all together story.

WEBE and WICC have been in the same studio building for several decades.  The Pacific Recorders and Engineering equipment, while great, is tired and worn out.  On top of that, an F1 tornado ripped the AC units off the roof last June, ripping the membrane and doing extensive water damage to the facility.

The cleanup/water damage mitigation took some time.  All of the carpet and ceiling tiles needed to be replaced.  The walls needed to be resurfaced with new drywall.  In some cases, modifications such as removing a storage closet from the engineering room, moving a door, building a new talk studio and WICC control room needed to take place.  In short, lots of dust, dirt and disruption to the station equipment and staff.  It has not been trouble free, as several times computers and consoles failed due to age and dirt.

Sometime about the beginning of December, new equipment and furniture began to show up and the project was underway.

Cumulus Bridgeport new equipment

Cumulus Bridgeport new equipment

All of the new equipment was stored in the program directors office.  Heh, the program directors office.

Cumulus Bridgeport new rack room

Cumulus Bridgeport new rack room

A new rack room was designed around the old one.  The old racks are out of the picture to the left.  The original rack room had a door into the hall, that has been replaced by viewing windows, the door has been moved to the engineering office, next door.  I kind of like the windows, it lets visitors see the fancy computers but keeps them out of the room itself.

Cumulus Bridgeport Op-X servers

Cumulus Bridgeport Op-X servers

The existing automation system is being replaced by Op-X.  This is the business end of the Op-X audio servers.  All of the network connections are Gigabit using Belden Mediatwist (1872A) Category 6 cable.

Cumulus Bridgeport wire wall

Cumulus Bridgeport wire wall

All the wiring from the studios and racks are brought to this wall.  The terminations are Krone LSA-PLUS blocks.  AES/EBU digital and analog audio is run on Category 5e cable.

Cumulus bridgeport wire wall Krone block

Cumulus bridgeport wire wall Krone block

Krone LSA-PLUS termination block with Belden Mediatwist cable.  All rack and studio wire runs are terminated on this style block.  Notice the wire labels, every run is labeled with both termination ends and use.  Mediatwist cable is fairly easy to work with, the pairs are bonded, so a special tool is recommended to quickly separate the wires.

Cumulus Bridgeport wire tray

Cumulus Bridgeport wire tray

Wire tray between the racks and wire wall.

WICC new Axia console installation

WICC new Axia console installation

The new WICC control room and talk studio.  The Axia consoles are pretty slick.  They are not a true mixing console in the traditional sense, they are more like a control surface.   Most all of the audio inputs are in the rack room, however, the microphones are digitized in the studio and sent over an IP network to the rack room.   All input and output channels are computer configurable and remote controllable.  Console inputs also have onboard mic preamps and full processing.

Cumulus Axia console set up

Cumulus Axia console set up

Axia console control software.

New WICC talk studio furniture

New WICC talk studio furniture

The new talk studio set up.  This is located where the news room used to be.  In order to stay on the air and maintain the old studios, a sort of musical chairs system needs to be played.  In the end, the WEBE studio and one production room will end up where they started, everyone else will be in a new space.  The news room will end up where the current WICC control room is.

Cumulus Bridgeport network switches

Cumulus Bridgeport network switches

Network audio switches.

Cumulus Bridgeport network patch panel

Cumulus Bridgeport network patch pane

Network patch panel, notice the T568B markings.

Currently, the program directors are loading all there material in the Op-X system.  The time schedule is to transfer WEBE into a temporary studio in about two weeks.

More updates as the project progresses.

Update: The new Axia equipment and Op-X automation is on line as of 2/24.   More pictures to follow.

Update 2: For more information on how the Axia consoles are made, check out A broadcast console makers perspective.

Update 3: More pictures:

WICC new studio with Axia console

WICC new studio with Axia console

WICC studio is nearly done, just a few odds and ends here or there.   This is located where the former talk studio was located.

WICC talk studio

WICC talk studio

WICC talk studio, host and four guest positions.  This is located where the former news room is.

Former WICC air studio, gutted

Former WICC air studio, gutted

This is the former WICC control room.  It has been gutted and several walls are being removed.  This will become the permanent WEBE control room when it is finished.

WEBE temporary control room

WEBE temporary control room

WEBE temporary control room.

WEBE old control room, gutted

WEBE old control room, gutted

The former WEBE control room, gutted.  All the carpeting has been removed and 1/4 inch drywall is going over the old, glue encrusted drywall.  This room will become a production room.

WEBE WICC rack room

WEBE WICC rack room

WEBE WICC rack room viewed from the hallway, approximately where the door to the room used to be.  The old racks to the left are being stripped out and removed.  All of the stations are now on the air from the new racks.

Which do you prefer, GPS or 4G data?

Block II GPS satellite

Block II GPS satellite

In some locations, it is apparently going to be an either or situation if this is to be believed:

Representatives of the GPS industry presented to members of the Federal Communications Commission clear, strong laboratory evidence of interference with the GPS signal by a proposed new broadcaster on January 19 of this year. The teleconference and subsequent written results of the testing apparently did not dissuade FCC International Bureau Chief Mindel De La Torre from authorizing Lightsquared to proceed with ancillary terrestrial component operations, installing up to 40,000 high-power transmitters close to the GPS frequency, across the United States.

Sound vaguely familiar?  Seems that LightSquared took a page from the iBiquity play book when it comes to dealing with the FCC.   The article goes on to say:

On January 26, the FCC waived its own rules (emphasis mine) and granted permission for the potential interferer to broadcast in the L Band 1 (1525 MHz—1559 MHz) from powerful land-based transmitters.

A little research on the LightSquared website shows they are rolling out an extensive L band 4G data network, not exactly what I would call broadcasting, at least not yet anyway.  GPS system inhabits 1559 – 1610 MHz, centered around 1575.42 Mhz  in the L-band.  The signals coming from GPS satellites are very, very low, with the open sky signal around -130 to -135 dBm.  Indoor signals can be as low as -150 dBm.  Further, GPS receivers currently in the field were not built to operate in environments with high levels of RF energy on nearby frequencies.

So, who uses GPS?  Just about everybody, including the military, the aviation industry, broadcasters, and general public.  Think about all the confused drivers who can no longer find their way to the grocery store without Tom-Tom.  By far, the biggest impact is likely to be the entire cell phone network, which depends on GPS for it’s multiplex timing.  It seems very likely that LightSquared network will be installed on existing broadcast and cell towers, right on top of the current cellular tenants.  Even if they work around this by providing better GPS receivers with high pass filters,  many existing consumer and aviation GPS receivers will be useless.

The potential interference is charted here:

Interference to consumer grade GPS receivers

Interference to consumer grade GPS receivers

For FAA certified GPS receivers, the data is worse:

Interference to FAA certified GPS receivers

Interference to FAA certified GPS receivers

The FAA certified aviation receivers are more sensitive, therefore, more likely to be impacted.

It makes me wonder, what is going on in Washington?

UPDATE: March 3, 2011, KNX, Los Angles runs with the story: Planned 4G service could cause widespread GPS jamming

Axiom


A pessimist sees the glass as half empty. An optimist sees the glass as half full. The engineer sees the glass as twice the size it needs to be.

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
~1st amendment to the United States Constitution

Any society that would give up a little liberty to gain a little security will deserve neither and lose both.
~Benjamin Franklin

The individual has always had to struggle to keep from being overwhelmed by the tribe. To be your own man is hard business. If you try it, you will be lonely often, and sometimes frightened. But no price is too high to pay for the privilege of owning yourself.
~Rudyard Kipling

Everyone has the right to freedom of opinion and expression; this right includes the freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers
~Universal Declaration Of Human Rights, Article 19

...radio was discovered, and not invented, and that these frequencies and principles were always in existence long before man was aware of them. Therefore, no one owns them. They are there as free as sunlight, which is a higher frequency form of the same energy.
~Alan Weiner

Free counters!