Heil Sound Systems

At the same time Reed Ghazala was discovering circuit bending, another Midwesterner was getting involved in the creation of the sound systems that would change the way live rock and roll music was performed around the country and around the world.

Bob Heil is an exemplar of the creative fusions that can happen when an ear turned on to the power of music also develops the knack for technical innovation. Born on October 5 in 1940 at age ten he was an avid accordion player. At age thirteen his parents gave him a B3 Hammond organ. This gift gave him a life in music, and in turn radio, that kept him busy with creative fun and innovation for close to seven decades.
Heil quickly mastered the Hammond and at an early age got a job playing organ in a restaurant where he made fifteen bucks every weekend. Two years later, with even more chops, he became the organist at the Fox Theater in St. Louis. Built in 1929 by William Fox the movie palace was designed to be a showcase for the films of the Fox Film Corporation. Throughout the 1960s it was one of the leading movie theaters in St. Louis and has now been given another life as a performance arts venue.

The organ at the Fox Theater was massive and had over 4000 pipes. Heil had to tune and voice the pipes. This job gave Heil hands on practice in concentrated listening. He had to go in, learn all the harmonics for the pipes and be able to dissect what he was hearing.

Heil, K9EID, has left his mark in music and amateur. The passion for radio also came to him young when got his ticket as an amateur radio operator at the age of fifteen in 1956. The hobby was quick to become an obsession. He plugged the earnings from his organist jobs into radio gear and began a lifetime of tinkering and working with audio and radio circuits. At the time there was excellent propagation on the amateur radio bands, and the six meter band, known to aficionados as “the magic band” was hopping with contacts both close and far. Anyone who wanted to get on the portion of the spectrum to make contacts and hear distant stations was in luck. One night while Heil was tuning around the six meter band he heard something horrid and strange. It was an operator talking on single sideband, not at all common at that time in the six meter portion. On another evening Heil heard him again and they got to talking. Soon they started meeting up on the radio to talk every night. They became fast friends on the air and one day this new friend, Larry Burrell, K0DGE, asked him to come see him in person.
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Larry happened to be chief engineer at KMOX. Heil was blown away when Burrell showed him around the studios and control rooms of the mighty Midwestern AM station. Heil wanted to get on 6 meter single sideband just like his older friend and asked him if he would build him a unit. His friend told him no, he wouldn’t build one for him but he would help Heil build one for himself. This proved to be a far greater gift than being given a radio. As Burrell elmered Heil and helped him build his own rig to do single sideband on six meters it sparked Heil’s love for building. After putting together a transverter for 6 Meter single sideband, he built one for 2 meter single sideband. 

Organs and Antennas

At school Heil wasn’t doing so hot. Music and radio were his passions, and he continued to fund his habit for radio from the work he got as a musician. Yet somehow he managed to scrape by, and with his parent’s encouragement, got into another beloved aspect of the hobby, setting up antennas. These antenna’s would prove to become important later in his career as a maker of high fidelity microphones and other audio equipment for musicians and radio operators.

One antenna he put up was a Telrex 6 Meter spiral array. Another was a 75 Meter dipole, a phased array also made by Telrex. Playing around with these antennas Heil learned how take them in and out of phase using coaxial cable.

Antenna phasing is used by hams and shortwave radio stations for beamforming -a technique that focuses a wireless signal towards a specific direction and receiving device, rather than having the signal spread out in all directions as it typically does from conventional broadcast antennas. Phased arrays are especially desirable on the lower HF band where conventional beams are not feasible. In the VHF and UHF ranges of the radio spectrum most hams use Yagi type antennas for beamforming. A Yagi is different than a phased arrays in that only one element is driven by the transceiver. The rest of the antenna elements are parasitic, in that they re-radiate the signal driven by the radio at different phases. However, when an array is truly phased, all the elements are driven directly by the radio in different phases. Having a phased array allowed Heil to send and receive signals in specific directions so he could work different amateur radio stations in North America and around the globe going east, south, west or north. 

One day Bob Heil got a call from Robert Drake, founder of the R. L. Drake radio company. Founded in 1943 Drake’s company made high and low pass filters for government and amateur radio operators, and after WWII he started making equipment for hams. Robert Drake was interested in one of the radios Heil had built, a kilowatt transmitter for 2 meter SSB.

As Heil recalled Drake telling him, “’We have a little meeting here at our club and I would love for you to come here and spend a day with us.  It's actually a couple of days.  We do it once a year in the Biltmore Hotel downtown.  We cleared out all the furniture on one of the floors and we'll have Art Collins and the guys in one room. You have Carl Mosley and his antennas in another.  We'll have Wes Schum from Central Electronics. We'll have Bill Halligan of Halligan,’ and on and on.  He names his list; I'm going, ‘Whoa.  What do you want me to do Sir?’ ‘We want you to come and tell us how you built this station.’”

This gathering was the Dayton Hamvention, and it quickly grew into one of the two largest annual gatherings for amateur radio operators and manufactures in the world. Heil came and gave his presentation and it was well received by the manufacturers and other hams in attendance. Part of the very purpose of the amateur radio service as defined by the FCC is to advance the state of the radio art. It is this experimental aspect of the radio hobby that has long been a beacon for some of its brightest stars.

After Heil’s presentation he got to talking with a British man who was there with his J. Beam Company. The man was looking for someone like Heil to do some experiments with an antenna they had built, and they asked him if he would like to carry out the work. He was more than willing, so they sent him what any ham would be happy to play with: a 128 element antenna array built for the 2 meter band. After shipping the massive array to him, he was helped by a contractor and fellow ham K9EBA who helped him put up such a beast of an antenna. He had another friend who worked for Motorola who also helped. The fact that his parents let him put up fifty foot wide antenna in the vacant lot behind their house was another blessing working in his favor.

This was the antenna Heil used to get started in 2 Meter moonbounce using VHF SSB, but before he got into that he first got another job, this time at the Holiday Inn in St. Louis where he built them a pipe organ for their four star restaurant. It was extremely rare to have a pipe organ in a restaurant and this helped the Midwest spot become a destination for travelers and organ fans on both sides of the continent.

In building the organ Heil again had the support of mentors, this time from Martin Wick of the Wick Pipe Organ Company, whom he’d met through one of his music teachers. He became close friends with Wick and would stop at his plant in Highland, Illinois on his way from Heil’s hometown of Marissa before going to play at the Holiday Inn in St. Louis. Wick had shown him one of the little theater organs he’d installed in a private home, and that gave Heil the idea of building a similar instrument for the restaurant at the hotel.

Once approval for the plan was in place he would go up to Highland every day to work on putting it together under the guidance of Wick and his employees. It took him about a year and a half to build the organ with five ranks of pipes, a blower, reservoirs, relays and a large console. Ever curious Heil wanted to learn how to voice and tune the organ himself just to see if he could do it, and with a bit of guidance from his mentors, he added this skill to his chest of valuable knowledge.   
 
After he built the organ he got paid to play it six nights a week, and when he looked over the rack as he played he saw the sign for Mosley Electronics. Fate had conspired to place him just across the street from the Mosley antenna plant.

Mosley Electronics was the brainchild of Carl Mosley, W0FQY, later K0AXS, a ham who got his start in the world of radio back in 1918 when spark gap transmitters electrified the air with their crackling sound. In the late 1930’s and early 1940’s Mosley started making equipment, starting with the 3/4" tube socket that was standard equipment for most amateur radio operators at the time. He was working out of his basement when he started this operation, but soon he had so many orders he had to grow his business, hire employees, get additional help.

As his business grew Mosley entered the market for creating accessories for television as the TV era dawned in the 1950’s, building feed thru insulators, wall outlets and plugs. In 1951 he got into the antenna game with his famous “Vest Pocket” design for his fellow hams.  The development of the design lead from monoband to multi-band and from there to the tri-band Vest Pocket utilizing one feedline.  This innovation led to the antenna becoming a mainstay, and for antennas in general to be the centerpiece of his business, and the building of the factory in St. Louis.

Military and industrial antennas were also being made by Mosley and it was these innovations that led to the creation of the WWV antenna for transmitting time signals. In 1955 his company created the Trap-Master TA-33 amateur tri-band beam setting the standard in the field.

From Marissa to the Moon

St. Louis was also the home of McDonald Aircraft. In 1959 they were busy building the Mercury capsule for NASA. Once a month seven astronauts from the agency came to train at McDonald, and they stayed at the Holiday Inn. They listened to Heil play the organ, and he got to be on friendly terms with the space cadets. One of them was a man named Alan Shepard whose father had also been an organ player and he was intrigued by the fact that the hotel had put such a custom built instrument inside the restaurant. As Heil and Shepard got to know each other, Heil told him about his ham radio hobby. He showed Shepard some pictures of the huge VHF array he had put up.

Heil recall’s their conversation: "‘Wait a minute, you have this thing working?’ I said, ‘Yes.’ ‘Can we borrow it?’ I said, ‘Well, of course.’ ‘Ah,’ he said, ‘This would be great.’ I said, ‘Well, you need to take it down?’ ‘No, no, no,’ he said, ‘You have a phone patch?’ I said, ‘Yes Sir.’ He said, ‘Here's what we’re going to do.  We're going to send you a signal from Houston in the telephone line. You patch it into your transmitter, into this 128 element.  You point that sucker up to the moon and what we want to know is what kind of delay time [it has].’”

Mathematically NASA had already calculated, without computers, what the delay time would be in bouncing a radio signal off the moon. Yet with Heil’s array they would be able to test how accurate their calculations were. Heil was around 20 or 21 at the time and his hobby had brought him into playing with the big leagues just a few years into the space race. 

“They would send little signals, just little shots, and they would listen for it.  They had, of course, fantastic . . .  I didn't know exactly what but probably 50 foot dishes, who knows, but it was NASA.  That was just such a big deal for me,” Heil said of the time.

For four hours a night, six nights a week he would play the organ for his job, and the rest of the time he spent building amateur radio gear, doing moonbounce experiments on VHF SSB with NASA, and making contacts on the radio. Around this time Joe Hall helped him get one of his transverter’s that he had built onto the market, and it was the first one to be sold commercially.
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All this, and Heil had never gone to college, having barely graduated highschool. “Amateur radio was my college professor” he is fond of saying.

Heil Sound System

In 1966 Heil was inspired to open up his own Hammond organ and music store in his hometown of Marissa, Illinois. He dubbed it Ye Old Music Shoppe and it was destined to become the rock and roll capital of the world. One day a high school kid came in with a guitar amplifier and asked Heil if he’d be able to fix it. Ever curious he took a look inside and saw the tubes and other components were similar to the ham radio gear he tinkered on. With his trusty soldering iron he fixed it up for the guy. This happened to be one of the guitarists who was later a member of REO Speedwagon. He and other rock and rollers started patronizing Heil’s shop and he started to develop a reputation with the rock music crowd, even though it was a genre he knew nothing about himself.

His shop started renting Hammond B3 organs to musicians and bands who were on tour in the area, often playing at the Keil Auditorium. People like Janis Joplin, Jimi Hendrix and Ted Nugent would come in, and after they rented the organ, they’d ask him about the PA system in the venue. Heil didn’t know much about the PA’s in the concert hall, it wasn’t an interest to him. He was interested in the sound systems for his organs. But he knew the little bitty columns of speakers where the bands played tended to sound horrible.

Fate intervened in his life once again at this juncture, when he went to go visit his old friend George Bales the stage manager at Fox Theater in 1968. When he got there he saw a bunch of boxes outside the stage door. George told him the theater was putting in a new set of speakers, and those were the old ones, being thrown out.

"‘Wait a minute.  You're throwing those away? Can I have them?’" he asked his friend. His friend said “‘Sure””. Heil recalls, “The Ham Radio in me kicked in, I went and rented a truck.’”Ham’s have always been great scavengers of material and parts. Where one person might see old electronic junk a ham sees possibilities.
Heil got them and took them to a vacant building he had in Marissa and started experimenting. The speakers were Altec 4’s and they were huge, about 10-feet-wide, 8 feet deep and 8 feet tall, and he had four of them. He put some radio horns in them, and got some JBL drivers and some McIntosh amplifiers. Next he needed a mixer and got an Altec. From all of this gear he put together a great sounding PA. Unknown to him, nobody else in the music business was putting together sound systems in this manner.

A manager for one of the venues got wind of the PA and asked him if they could use it when they brought in different acts from Nashville, and Heil said yes. To Heil it was just a big hi-fi system, but the acts and the venue manager went zonkos over the sound it produced. Dolly Parton was among the first musicians who got to use the system.

At that point people around St. Louis started to talk about Heil’s achievement. Another manager came up to him at a show and asked him if he would take the PA on tour with the band the guy worked for. Heil explained he’d never been on a tour, but that he had a couple guys who liked rock music who worked for him, and that he’d get them and the gear rounded up and along to do these shows in Ohio. After two days into the this gig he found out the lead guitarist for the band was a ham radio operator. His call sign was WB6ACU and his name was Joe Walsh, and the band was the James Gang. Walsh and Heil hit it off and so began a lifelong friendship.

The next big jump in the progression of Heil Sound took place on February 2, 1970. The Grateful Dead were scheduled to play at the Fox Theater. Good friend of the Grateful Dead, the "Bear" Augustus Owsley Stanley III was going to run their sound system. Owlsey was himself an amateur radio operator, having secured a license during his stint as an electronic specialist for the United States Air Force. While in the service he also picked up his general radiotelephone operator license. His technical background served him well as an audio engineer and as a clandestine LSD chemist, who supplied the Dead and their fans with copious amounts of the hallucinogenic drug. It is estimated that between 1965 and 1967 alone that Owsley had produced no less than 500 grams of LSD, amounting to a little more than five million doses. When he first got started making the stuff, acid wasn’t yet illegal, but it quickly became so, and it didn’t take long for the law to catch up with the man and his operation. With drug charges pending against him, Owsley had been ordered not to leave the state of California.

That pesky little detail didn’t stop him from going on the tour though. As Heil recalls, “They were going to do a short little Midwest, East Coast tour and their sound man was on probation out of the state of California.  He wasn't supposed to be out of the state, but the drug agents and the FBI they found out that he was going to be on tour so they went to the first job.  The first job and they sat and waited till they were finished playing.  The group came on to St.  Louis the second date.  Now there were no cell phones.  There was no communication in those days.  The group shows up at the Fox at 4 o'clock in the afternoon.  There's no PA.  There's no Owsley.  The group was the Grateful Dead.  Well, they call back to their office found out that Owsley was in jail.  The PA was confiscated; their group was not going to continue.”

George Bales from the Fox called up Heil with this situation on his hand, asking if he still had those speakers he had given him. The Grateful Dead were at the theater without a PA and they needed some help.

Bales put Heil on the phone with Jerry Garcia and the two talked about the equipment Heil had at his disposal and Garcia got amped. They would be able to pull off the concert in style. “We went up there and we did the show and it was marvelous”.

For the gig Heil also brought in a Langevin studio recording console he’d modified to use with the speaker system in a live music setting. He’d had help in rewiring the board from his friend Tomlinson Holman who was at the time going to school at the Universeity of Illinois. Holman later went to have his own prestigious career in sound as the creator of the THX theater sound protocol. One of the things that made the mixing board innovative was an electronic crossover Heil had built into the console.

Heil had some help from some early Deadheads in getting the show together. "My two roadies, Peter Kimble and John Lloyd, knew all the Dead songs — they were big fans. So that night they moved the PA, set it up and mixed the show."

Heil had also innovated a trick to deal with the pesky problem of feedback, every stage musicians bane. "We would run the microphones out of phase from the monitors, something that nobody had been doing yet. Since they were out of phase with the microphones and the FOH system, anything that leaked in from the monitors would be canceled out. As a result, we could get these things incredibly loud before they would feed back. That's one of the things that Jerry Garcia really loved."

The show was a massive success, and the Grateful Dead asked Heil, his crew, and his sound system to join them on the road. On that night the live sound system for rock and roll was born.

 “They took us right out of there that night on the rest of the tour.  Jerry and I became very good friends.  We could be here a long time talking about the things that we did together, the equipment, the technology, that's where I'm at with this.  It wasn't so much of the group as it was Jerry and his love for gear and what we could do with different things and help them.”

From that point on Heil started receiving more and more requests to do the live sound for touring rock bands. He did the sound for Humble Pie which is when he became friends with Peter Frampton, and he worked with ZZ Top among many others. Heil's setup had become an instant hit, and soon to be the template for the modern concert touring sound system.

He was on tour with Chaka Khan in Chicago when he got a call from The Who in Boston where they needed his help. He wanted to help them, but didn’t want to leave Chaka Khan stranded and wasn’t sure how he’d even be able to make it to Boston with the truck of gear. Heil Sound stored and kept all their traveling equipment in a 40-foot semi, the first people to do so. The Who suggested he rent a Tiger airplane, who were an airfreight company. He got a friend with another PA system to cover Chaka Khan and they drove their semi onto a 707 jet and flew to Boston the next day.

Heil’s sound system did what the Who needed it to do and set the standards for playing large arenas and coliseums. The Who used Heil’s system on the rest of the tour and from this encounter Heil forged a lifelong friendship with Pete Townsend. Townsend later called him to London because he had an idea for Bob. He wanted to know if could build a PA for quadraphonic sound. Once again up for the task Heil Sound built the system used for the Quadrophenia tour in 1974.
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As the 1970’s progressed at any one time Heil would have three of his custom PA systems on tour with acts like J.  Geils, Jeff Beck, ZZ Top, and others, with a crew of 35 people working to make it all happen. Heil was also responsible for the first use of monitor speakers by musicians in concerts so they could hear themselves playing in these huge venues, and was the first to build stage monitors that didn’t feedback. All his knowledge in building came from the expertise with electronics he’d developed as a ham radio operator. 

The Talk Box

With his buddy Joe Walsh he also built a talk box for guitar that could withstand the rigors of stage. The talk box is an effects unit that shapes the frequency content of a sound, usually of a guitar, by way of applying voice to the sound of the instrument. The original talk box had been invented by musician, band leader, and amateur radio operator Alvino Rey, W6UK back in 1939. Rey got the idea that he could wire a carbon throat microphone in such a way as to modulate his electric steel guitar. The carbon throat mics had in turn been originated for use by military pilot communications, so pilots could communicate even in extremely windy and noisy communications. Rey put one on the throat of his wife Luise King who was a singer in The King Sisters group. She would stand behind a curtain and mouth the words alongside the guitar to modify its sound. It was a move that added unique coloration and novelty to his performances.

Some producers at a studio in Nashville had shown the trick to Joe Walsh, having given him a little box with a big hose that he drove with his guitar amp. It was good enough for the studio but the set up wasn’t powerful enough for the big live concerts Joe was playing at the time in his band Barnstorm. Heil and Walsh, along with the latter’s guitar tech “Krinkle” combined a 250-watt JBL driver and a hi-pass filter to make the first Heil Sound Talk Box. It was used on Walsh’s solo single, Rocky Mountain Way.

Later Heil’s Talk Box was used to great effect by Peter Frampton, who received one as a Christmas gift. His girlfriend hadn’t known what to get him for the holiday and called up Heil for advice. Heil had just the thing for him and sent her a hand-built Talk Box whose components were housed in fiberglass and used a 100-watt high-powered driver. This was the tool that gave his Frampton Comes Alive! album and tour it’s signature sound, to the point where Peter Framptom and the talk box are almost synonyms.

A Dish for Hungry for Satellite Hunters

As the 1970’s rolled on into the ‘80’s Heil got bit by the satellite bug. His friend Bob Cooper was a guy he had done some of his moonbounce experiments with back in 1962. When he heard about some of Cooper’s shenanigans building a satellite dish that used a coffee can as a low noise amplifier (LNA) to pick up the backhaul of HBOs feed he made a point to reconnect with his old friend. Once a month Cooper had an informal get together in Oklahoma where he showed others how to build these satellite receiving systems, and Heil got into the game of TVRO or television receive-only.

Communications freaks love to receive anything and satellite transmissions are particularly exciting to some devotees. At the time a dedicated group of communications hobbyists were getting into receiving the uncut and unedited content of satellites as it was transmitted unencrypted an “in the clean” to different local stations who would slap on their particular channel graphics and logos before presenting as a packaged TV program. For instance, sports broadcasts, would be transmitted with raw footage later to be edited during the highlights section of a local news program.

​After getting into the technical aspects of this for awhile, Heil got to be one of the first ten on the test team for the commercial satellite operation DirectTV in 1991. His store was one of the first to sell DirectTV. It was around this time his company also worked on installing custom home theaters, but after his stint of time served in this capacity, he got out of the satellite game, and his mind turned once again to the radio hobby. 

Hi-Fidelity for High Frequency

One day Heil turned on his radio and didn’t like what he heard on the air. It wasn’t what his fellow hams were rag chewing about that caused him to be disconcerted. It was how they sounded when they talked to each other. He wondered where all the great sounding Art Collins radio gear had gone, and how it was that such good equipment had be replaced by gear that did not have the same audio quality. It was in seeking a solution to this problem that he started making microphones for hams and musicians.

Of the many mentors Heil had over the years, Paul Klipsch was another whose knowledge and friendship changed his life. Klipsch was an engineer and a pioneer of high fidelity audio. Among the many patents he held was one for seismic prospecting and recording seismic waves. Seismic prospecting is a method of geophysical exploration where vibrations are made in the earth by firing small explosive charges, and other means, into the ground. The resulting waves are measured and studied so to reveal the underlying strata, or composition of layers of rock and soil.   [Klipsch work in these fields possibly overlapped with the seismic work and interests of Gordon Mumma.]

Klipsch had been dissatisfied with the quality of phonographs and early speakers in the same way Heil had been dissatisfied with the sounds of hams on the air: they both thought each had sounded bad. Neither were content to let things stand in such a state. Klipsch used his technical abilities to create better sound systems and environments, that led to the development of the corner horn speaker that was a vast improvement over previous iterations of the phonograph horn.

Klipsch had his lab in old AT&T exchange building and Heil liked to visit him there. He directed Heil to study the work put out by the idea factory of Bell Labs, specifically the work of Dr. Fletcher and Dr. Munson. These two Bell Labs scientists gave Heil a secret weapon in his quest for audio excellence: the Fletcher Munson Curve.

Dr. Harvey Fletcher had been born in Utah in 1884, graduated from Brigham Young High School in 1904 and University in 1907. Gifted in physics and mathematics he decided to go to the University of Chicago for his doctorate. Nervous about going to the big city on his own he persuaded his sweetheart to marry him, and they went together, even though he had not yet been admitted to the school. Robert A. Millikan, a Nobel prize winning physicist, became a mentor to Fletcher and helped him get started at the University, where he eventually earned the first summa cum laude ever awarded by the institution. During this time period Fletcher worked closely with Millikan who figured out how to measure the charge of an electron, research that was fundamental to the growth of electronics and broadcasting technologies.

Fletcher eventually hitched his star to the Western Electric Company in New York, and from there went on to become the Director of Physical Research at Bell Laboratories. It was there under the auspices of pure research that his gifts fully blossomed. He published 51 papers, wrote two books, and had nineteen patents. In particular his two books, Speech and Hearing, and Speech and Hearing in Communication, set the precedent for further work on the clarity of audio.

One of the things Fletcher was interested in was how the sound of a typical talker was heard by a typical listener. He realized that small imperfections in speech could have drastic effects on a listener’s ability to perceive what was said. For the telephone system this meant they had to do everything they could to make sure their own technology did not interfere with its primary purpose of allowing distant voices to connect with each other. The instruments used to convert sound waves into electrical form and then back into sound waves needed to be able to do so without causing distortion.  

Fletcher also conducted with his colleague Wilden Munson the first research on the frequency response of the human ear in 1933. By playing a series of tones they were able determine how listener's perceived loudness at different frequencies and from their results they learned that the frequency response of the human ear is non-linear. They also learned that frequency perception varies based on amplitude. They used the data from these experiments to create the Fletcher-Munson curve, which shows that the frequency range which the human ear finds most sensitive is between 2 kHz and 5 kHz.  It was all published in their paper, “Loudness, its definition, measurement and calculation" published in the Journal of the Acoustical Society of America.
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AT&T used this research to equalize the phone lines and keep the maximum articulation of speech at the sweet spot between 2 and 3 kHz. Assiduous study of the Fletcher-Munson curve allowed Heil to make his next breakthrough and implement these findings in a line of equalizers and microphones. 
Equalizer’s had already been made for the Hi-Fi stereo market, but for some reason hadn’t been put together for use by hams. Heil corrected that, and in 1982 he was the first to build one specifically for use on the ham radio bands, the EQ200. He made this available as a DIY kit, after an article he wrote on it for QST Magazine set the ham community aflame. “Voice communication absolutely needs articulation,” he wrote. His equalizer helped to roll off all the frequencies below 100 hz, which only muddied things up and were a waste of RF energy.

From Phased Array Antennas to Microphones

After he had the equalizer Heil realized there was still a problem with microphones used by hams. “They're bassy, they're tubby, they have no rear rejection,” as he put it. So Heil got into the microphone business.  He worked with Icom and Yaesu on the microphones for their radios, and then went on to make his own microphones for ham radio, first the HC series, and later the Gold Line.

Heil’s friend Joe Walsh was a big fan of Heil’s microphones for ham radio, so much that he thought they should be reworked for the stage with the professional musician in mind. In 2006 Walsh asked him to adapt his Gold Line ham microphone for him. Working closely with Walsh, he came up with the Gold Line Pro for his fellow musicians. Because he learned how to take it out of phase, it is the only microphone to have 40 db of rear sound.

The success of his microphone came on top of all his previous experience and knowledge in radio and music. For the microphones he got an insight from his phased array antenna systems he used as a ham. Antenna phasing is used for ham radio beamforming, or pointing a signal in specific direction a person wants to transmit towards. In shortwave broadcasting, for instance, it is used to aim a signal at certain parts of the globe. Hams use it for making contacts in countries and states they want to work. Generally they are a set of different antennas combined to work as one.

To beamform on the shortwave and HF ham frequencies different lengths of coaxial cable are used and attached to antennas that different create radiation patterns depending on selection. Another way is to hook them up into an RF matching network that provides -90° and +90° delays and relays for the configuration of each element. This enables a station to listen to other stations using the same-frequency in different locations.

Heil took this knowledge of taking antennas in and out of phase to pick up particular stations, and used it in the microphone which he realized could also be made to out of phase and give it a huge amount of gain in the rear side of the mic, something uncommon. His design proved to be as popular with musicians as it was with hams.

At the time of this writing Heil is eighty years old, and continues to get on the air every day with his various ham rigs and talk on his phased array antenna system. He was honored by the Rock and Roll Hall of Fame with a display on Heil Sound, the only display at the museum to feature an equipment producer. Heil remains a passionate organ player, and it is fitting that he is able to be heard playing live every week on shortwave radio at the time of this writing. International station WTWW out of Lebanon, Tennessee blasts his organ playing at 100,000 watts on 5085 kHz every Saturday at 8 PM Central Time.

Heil’s sound systems have rocked the world and they never would have been possible if he hadn’t been swept up into the hobby of ham radio.   

References:

Motes from presentation to OhKyIn Amateur Radio Society from a talk called “The Science of Audio” Bob Heil gave over Zoom on January 5, 2021.

Archived on YouTube: https://www.youtube.com/watch?v=RJiO_vFa2Tc

https://www.qsotoday.com/transcripts/k9eid

https://www.nutsvolts.com/magazine/article/how-phased-array-antennas-work

https://play.fallows.ca/wp/radio/ham-radio/ham-radio-beamforming-phased-arrays/

http://mosley-electronics.com/mosley_history.html

For more on Bob Cooper, this interview from Mother Earth News: https://www.motherearthnews.com/nature-and-environment/satellite-television-zmaz80mjzraw

http://abc.eznettools.net/byhigh/History/Fletcher/DrHarvey.html

http://play.fallows.ca/wp/radio/ham-radio/ham-radio-beamforming-phased-arrays/

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Read the rest of the Radiophonic Laboratory: Telecommunications, Electronic Music, and the Voice of the Ether.