During Jr. High and High School, this would be in the time frame from 1971 through 1977, friends and myself operated a number of bootleg radio stations.
Some of my friends were captured by the Federal Communications Commission. Somehow I was lucky and evaded capture but there was a couple of close calls.
The friends in question shall remain nameless, even though I am sure it is well past the statute of limitations and I am also pretty sure the FCC knew who and where all the players were and pretty much left us alone until we caused trouble.
I met several of my friends through our mutual involvement with pirate radio. One of them had connected a volt meter to the AGC line (this is a voltage in a radio used to control the gain to compensate for varying signal levels). By driving around until they got the strongest voltage they located my station. It’s obvious to me that if they could locate me with such primitive equipment, the FCC could have done so very easily.
The friend that chased me down had also operated a pirate radio station, he lived just a few blocks from the high school I went to. It was at a very low elevation and the ground was very damp. The excellent ground conductivity allowed his very low power station to get a pretty good range. His transmitter was essentially built from table radio parts, it used a 50C5, a common audio output tube in what was known as all American five tube table radios, in a simple power oscillator configuration. It probably had about a watt of output.
My station also started out as a converted table radio, initially operating on shortwave bands, then later the AM broadcast band at 1200 khz. When operating on the AM broadcast band I used a number of converted and home made transmitters. All except for the very last one was tube based.
A DX-40 Ham Transmitter
The first AM transmitter I can remember running was a very crudely converted DX40 HAM transmitter. I say crudely converted because the way I got the final Pi section to tune down into the AM band was to stuff the ferrite cores from AM radio antennas into the coil, and add some fixed capacitors to bring it down into the AM broadcast band range. The oscillator was a simple LC oscillator which had a lot to be desired in terms of frequency stability. I used an audio output transformer backwards driven by a tube audio amplifier backwards for modulation.
Friends and myself built a studio in my parents basement. It was not a bad setup actually. We first borrowed some broadcast turntables from the high school radio station, then when we needed to give those back, we bought some used. The ones we got used were pretty tacky by contrast but they worked. The microphone stand was a converted lamp, you know the ones with the spring loaded booms. We hung the RCA 77-DX microphone where the lamp socket and reflector would have been.
RCA 77-DX Microphone
I made regular trips to various broadcast stations in the area and got to know the engineers. We were able to obtain for free or very low prices used broadcast equipment, friends also helped obtain equipment through their connections.
From KGA, a station that was on 770Khz and was the only AM station to use a horizontal long wire antenna instead of a vertically polarized tower in the area, I obtained a Langevine compressor / limiter which we modified for asymmetrical limiting (so it would only limit on negative audio peaks but not positive) and a faster attack and release time so that it really squashed the audio good. We used an oscilloscope to set the modulation so the negative peaks would approach but not exceed 100% in order to avoid splatter. If you overmodulate an AM signal, the carrier can’t go less than zero so the audio signal is very abruptly clipped at that point generating high order harmonics that interfere with neighboring stations.
We tried very hard to keep the station operating technically very clean to avoid causing interference and avoid drawing the wrath of the FCC, we ran at this power level for nearly five years before a broken antenna mistuned the final state of the transmitter resulting in third harmonic interference to the 80 meter ham band, and that is what finally got the unwanted attention of the FCC.
Until that event we operated much of the time 24 hours a day with friends volunteering for various air shifts. We gave out our telephone number over the air so the FCC wouldn’t have even had to use directional locating if they wanted to bust us. They never did, in spite of playing Dave Clark Five’s “Catch Us If You Can” as a bit of a taunt. Initially we used to call letters “KFUN”, but then found out that there was a legitimate station with that call and so switched to “KDXS”.
As I mentioned, our first transmitter was a crudely modified DX-40. Later we refined that into a less crudely modified DX-40, actually calculating the proper values for the final Pi section, ordered a high quality 1200 Khz crystal with the tightest specification we could get without a crystal oven. One of my friends had access to a well calibrated frequency counter (it used a 10 Mhz reference oscillator which you could verify was accurate by zero-beating with WWV) so we were able to very accurately trim our transmitters output frequency. We designed the final Pi section to have a high-Q and used high quality silver plated components, some of which were purchased new and some scarfed from military surplus, so that harmonic suppression and stability of this new transmitter was good.
Then I built a new transmitter from scratch, making the chassis in metal shop at school. At this time I was in 9th grade, still going to Jane Adams Jr. High but also went across the street to the high school for the radio class. So I enjoyed having access to metal shop and electronics classes at the same time. The new transmitter used much healthier tubes for the output and modulation. Although it ran with a similar power input as old transmitter, the audio section was far more powerful, we had about twice the audio power as plate input power so the transmitter was capable of very high levels of modulation. The modulation transformer was actually designed for the purpose so the audio quality of this transmitter was much superior. I also obtained an equipment rack and we had the whole works rack mounted.
I nearly electrocuted myself during the construction of this beast. The power supply was external and the plate voltage for the audio section (811B’s) was 1200 volts, 600 volts for the finals (807B’s), (and yes I do realize this is above the rated maximum plate voltages for these tubes but they ran fine this way). The connector for power I wired incorrectly swapping the pins for ground and +1200 volts resulting in a 1200 volt potential between the transmitter chassis and the power supply chassis. The power supply used solid state rectifiers so it was instantly on when turned on and had a metal on/off toggle switch.
I was building this in radio class at school. While leaning on the transmitter chassis with my left hand, and with a pair of wire cutters in my right hand, I switched the power supply on with my right hand. Instantly I had 1200 volts surging from my left to right hand, exactly the worst situation to be in with electricity since it puts the current right through the heart. The rapid contraction of the muscles in my arm launched the wire cutters into the overhead fluorescent lamps which then rained down pieces of glass. Somehow my heart kept beating through it all. I got chewed out by the instructor and got a small burn on the finger operating the toggle switch, but otherwise survived.
This transmitter in combination with the modified limiter that allowed audio peak excursions to go where they will and only limited negative peaks, resulted in a very loud but still clean sounding signal. It made the signal listenable at distances that otherwise would have been more marginal. With this transmitter we were able to cover from approximately where the old Rainier Brewery used to be in Seattle up to downtown Everett, the signal was very marginal at those extremes, not a signal that the average radio would pick up but a good communications receiver could still make it out.
We constructed a huge outdoor long wire antenna by running a wire from the corner of my house to a high spot in a pine tree nearly a block away with the permission of the neighbors inbetween. In the tree we put a pully and attached the wire via an egg insulator to flexible steel wire that went through the pully and then was weighted by a cinder block. This way as the tree moved in the wind, the pully / weight system would keep a constant tension on the wire.
Then I obtained surplus this massive KARR marine transmitter that was originally in service for the Alaska Marine Operator, a service allowing marine customers to talk to land based telephones. It used 3 4-400A’s in the final and two 4-400A’s in the modulator section.
In my opinion this was kind of backwards since the modulators operated in class AB and thus dissipated far more heat than the finals operating in class C mode. Class AB is a mode where the tubes are always conducting somewhat, it is push-pull and each tube is essentially responsible for half of the audio wave form. It is not very efficient. Class C is a mode where the tubes only conduct for a small portion of the RF cycle and they are essentially either not conducting or conducting hard so there is little power dissipation and high efficiency.
This transmitter might have been capable of several kilowatts if we could actually get power to it but probably wouldn’t have been able to fully modulate at that power level. It was designed for 208 volt three phase operation, but since we didn’t have three phase power we wired the plate transformer using just two sections of the core instead of three and fed it with a 220 volt 20 AMP circuit. We had Murry magnetic breakers which have a tweakable trip threshold and we were able to crank it up to about 25 AMPS. The modulation transformer was designed only for voice 300 Hz – 3 Khz voice operation and because of this it didn’t have enough turns for bass and when hit with heavy bass it would cause the modulator tubes to draw large amounts of current and trip the breaker. Between the modulation transformer being inadequate and not being able to get more power to it we were limited to about a kilowatt in practical terms.
We didn’t normally run this transmitter because I thought we’d have the FCC at our door very soon if we did. It intended to induce such a strong RF signal in things that anything with an audio amplifier would only get our station. I had a loop antenna with a seven watt Christmas lamp on it that I could carry around and it would light up the lamp. So it was a transmitter we mainly fired up for special occasions.
When it was running our signal instead of being marginal at the Rainier brewery and downtown Everett was actually fairly listenable.
This transmitter was technically a pretty clean transmitter with high quality LARGE silver plated coils and capacitors in the final, all of which was in an RF cage inside of another RF cage to minimize signal leakage directly from the transmitter. But at that power level any non-linear surface generated harmonics, and poorly shielded consumer equipment was just completely overwhelmed. When we’d fire this puppy up we were guaranteed an audience because anyone in the immediate vicinity couldn’t get anything else. So obviously operating at that power level in a densely populated residential neighborhood was not practical for any length of time, normally we operated with the smaller transmitter at about 100 watts.
At the time, this was before Washington State passed the inventory tax, nearly all the major record labels distributed out of Seattle, and we were able to get record support from almost all of them. Jerry Morris who distributed Capital records I believe, he was just the coolest. MCA was the stingiest. This was before they were part of Warner / Elektra / Atlantic (who were also pretty good to us). We also got records from the high school station when they retired them, and from some of the broadcast stations in the area when they retired them. In addition one friendly engineer of a popular Seattle Top-40 station allowed us to tape music in one of the stations production rooms.
Initially we operated at 1200 Khz which at the time was a clear channel and the only other station in the country using it was WOAI in San Antonio, TX. But another friend that ran a pirate station about four miles away also used this frequency using the call letters KLK. For a while we shared the frequency scheduling our transmissions to avoid colliding but later we ended up moving our station to 1210 Khz to avoid interference.
We mostly played music though we also did comedy skits and sometimes we’d put callers on the air randomly. At one point we made silly prank calls on the air, dialing numbers at random and asking people if their (name the appliance) was running and if so they better go catch it. One lady we called answered the phone not with hello but with “I use a carpet sweeper”. Which for some reason we found amusing so we would call her periodically and air the conversation. And then there was fun things you could do with a telephone back then. Sears used to have this old mechanical Centrex, and any non-assigned numbers would be routed to a recording and would not give answer supervision (off-hook indication) thus it would allow you to call from anywhere in the world and not get charged. The recording would die periodically and this was well known to the phone phreakers. There was not good isolation between the channels so people calling could take to each other. Phone Phreakers would call from all over and we’d put it on the air.
I narrowly escaped trouble twice. On one occasion the FCC came to my house but the transmitter was not on and I was not home. My sister answered the door and they asked her how big the transmitter was. She assumed the big one, about the side of a large refrigerator, was the one we normally used and described it. Apparently the FCC engineers made a funny expression after this. But oddly enough we never received any notice from them at that point or verbal warning.
What did finally get the F.C.C’s attention in a negative way was an incident in which the antenna broke. I went in and noticed the plate current was way high and re-dipped it and didn’t think much of it, just figured someone bumped the knob or something, but it turned out that the antenna had broken and when I returned the transmitter it was playing tripler and broadcasting on the third harmonic which fell smack in the middle of the 80 meter ham band. I received a letter from R.C. Dietch who was the chief FCC engineer at the Seattle field office advising me that the FCC had received not one but three complaints of interference to the 80 meter ham band and that if we did not immediately correct the interference we would be liable for a $20,000 fine and/or two years imprisonment. Oddly enough the letter did not say anything about illegal broadcasting or order us to cease and desist, it just said stop the interference.
But, I had my first class radio operators license (had just obtained it) and knew that if I was apprehended the punishment would have been particular severe because I couldn’t claim ignorance. That was before the days of Ron Bailey and similar broadcast schools, back then you actually had to understand the material to pass the test. I wasn’t overly concerned about imprisonment because I was a minor at the time, and I didn’t have any money for them to take, but because I would likely lose my license if caught I decided to terminate illegal broadcast operations at that time. It was a long run, a fun run, but the illegal aspect was over at that time.
I mentioned other friends involved in pirate radio. One of them operated a station in Bothell Washington on the FM broadcast band. Prior to operating that station he lived in a different location and ran a bootleg AM station using a military surplus transmitter. He operated the station on 1570 Khz and there was a legitimate station, KUUU at the time, on 1590 Khz. The engineer of KUUU lived in the same area and his station was interfered with by the station my friend ran there. He had climbed up a steel power line tower and ran a wire down to his window for an antenna. The FCC visited him in response to the engineers complaint and informed him that he could not operate an AM broadcast station without a license. This all happened before I met him.
I met him in much the same way the other friend that tracked our station found me. I was tuning around in the FM broadcast band with a Sony Earth Orbiter radio and ran across his signal. It did not read on the S-meter but did achieve full quieting.
The sound quality was horrid, that was the first clue that it wasn’t a legal station. I listened for a while and like us he gave out his phone number over the air. He also had a group of friends volunteering to do shifts and ran the station long hours.
I called and after some discussion he agreed to allow us to visit and we went out and met and saw his operation.
It was all operated out of a very jammed bedroom. In his bedroom, in addition to his bed, he had a radio studio setup, the transmitter, another military surplus unit with a welding rod stuck in the antenna jack, and he was also an artist with an easel, and numerous drawing supplies. There were clothes and records and paper strewn all over. He would sleep in his bed with the lights on while someone else did a night shift on the station. There were half-eaten cheeseburgers and spilled milkshakes and God only knows what all else on the floor with various fungus specimens growing out of the pile.
He and his group of friends were quite creative and good at production, so the programming on his station was quite entertaining. He had little technical knowledge however and so the transmitter, in addition to being designed for narrow band voice modulation instead of wide band high fidelity with preemphasis, was also in a bad state of disrepair.
So myself and a friend of mine who was technically sharp modified his transmitter for him rebuilding the oscillator / modulator section to accommodate wide-band modulation. The final was a push-pull final using an 829B tube. This is a tube with dual power tetrodes I think, in one envelope. A grid resistor had failed and opened up on one side so the final was only operating on one section, essentially at half-power and higher harmonic output (push pull finals cancel the even order harmonics). We fixed the grid resistor as well. Then we built him a dipole antenna with a coaxial balun, that we put up on his roof. I also lent him a gates limiter I had borrowed from the high school, we had obtained the Langevine so didn’t need the Gates. The Gates wasn’t ideal as it was designed for AM and thus didn’t make allowances for preemphasis, but it was better than nothing.
After these modifications, his signal which previously didn’t read on my S-meter now pegged it seven miles away. And the audio sounded good. It was monaural but otherwise sounded good.
All went well until a kid at school heard about it. This particular individual was mentally handicapped, I don’t know exactly what was wrong with him but he’d do things like smoke three cigarettes at the same time because he thought it was cool. He was not a complete idiot but he was slow and socially awkward. He wanted to be involved in the station and the rest of us didn’t want to be so someone told him the station was down in Auburn, about 40 miles south of where it really was. Angry, he called the FCC and informed them of the operation. They apparently chased it down all the way from Auburn out to Bothell where it was located.
The engineer was the same person that had busted him running the AM station. They told him when we said you needed a license to operate an AM station it didn’t mean you could operate an FM station without a license. The engineer then did a weird thing and smashed the 829B final tube. This wasn’t a hugely expensive item, a replacement could have been easily obtained, but by this time my friend had his third class license and didn’t want to lose it. So he wrote a very apologetic letter to the FCC and ceased operating. They never replied or contacted him again.
And the friend that operated the pirate station also on 1200 Khz, he also operated a shortwave station on two frequencies twice a day. They called it the RX4M The Voice of Clipperton. Clipperton Island (pictured above) is a little atoll a couple hundred feet long and maybe 50 feet wide and about a foot above sea level at the highest point. Nobody lived there except some birds nesting. It was occasionally visited by scientists. He got QSL reports from all over the globe with this operation but also eventually got a visit from the FCC. It’s unfortunate that he was captured, amounts the lot of us, his operation was undoubtably the most well known and for good reason, in spite of primative equipment, the production was great. Unlike the rest of us who only received warnings, he was fined $750 at the time (counting for inflation that’s probably equivalent to about $2000 today).
After the interference warning I got from the FCC, we decided to try to do things within the letter of the law but totally skirt the intent of limiting coverage to about 300 feet. Part 15 rules allowed a couple of options, you could either limit power to 100 mw and not use an antenna longer than 10 feet (including the ground lead) or you could meet field strength limits. I questioned the FCC about whether final input power was measured with our without modulation. They told me that was the input power without modulation.
Ok, damn here was an opportunity. First, we shifted to 660 khz for this. That channel was quieter than 1200 / 1210 Khz and for some reason the lower frequencies tended to propagate better at the time. First we went to a type of antenna known as a British joystick. This is basically a an insulted form wound with a coil of wire and a capacitive hat at the top. This allowed the antenna to be resonant at 660 khz in spite of only being ten feet long. This had the effect of making it much more efficient than a simple ten foot piece of wire would be. With this antenna we could actually receive our signal several miles away with a transmitter using 100 mw dc input to the RF final.
But there was room for improvement. We designed a solid state final that when the modulation approached 100% on the negative swing the final power would increase to contain the negative swing essentially. In other words, there was a positive increase in power level as modulation approached 100% such that modulation would not increase above 100% as audio level increased but power would go up. This only scaled to a couple of watts though owing to the selection of RF output transistor and components. With very squashed audio from our modified compressor / limiter, it would essentially keep the transmitter at max output of several watts with modulation but lacking modulation it would be 100 mw. There was nothing in the part 15 specification that dealt with carrier shift so we made a transmitter intentionally with lots.
But this didn’t really buy us much and besides the funky way it would interact with AGC on AM radios made it sound crappy. At some point I had also heard of carrier current, where an AM signal is put into the power lines of a building so that radios within the building can pick it up. Normally such an arrangement is limited to the building because the pole transformers won’t pass the higher RF frequency. However, City Light, the power company in this region, has a funky arrangement where they tie the secondaries of the pole transformers together. That is, in addition to running the 2200 volt or whatever it is that feeds the primary of the pole pigs, they also ran three additional wires, ground and the two 117 volt opposite phases so the secondaries of all the transformers were paralleled. That way, if one had a particularly heavy load, it would spread the load to it’s neighbors to some degree, or if one failed, the houses served would still get AC power via the neighboring transformers.
So, I thought here is an opportunity to use carrier current in a way it was never intended. Carrier current also has power limits, I think around one watt but I do not remember the specifics, or field strength limitations. It occurred to me that we could use the power lines like a balanced transmission line, feeding opposite polarities of RF signal into the two 117 volt lines relative to ground, and that, being out of phase, the radiated signals would largely cancel. So we measured the impedance of the lines to ground at 660 Khz, and built a torroidal RF transformer to match the 52 ohms output of the transmitter to the power line.
This indeed did work to a degree. Using the earth orbiter radio as a primitive field strength meter, I found that the signal levels were actually higher about a block away from the house in either direction than right at the house. Apparently the lines tended to become increasingly unbalanced at that frequency with distance. We experimented with a the big kilowatt transmitter this way but when we operated it into the power lines, the lights in our house and the neighbors house (incandescent) would be blue-white bright and flash with the modulation. The stove sang loudly, the TV didn’t have recognizable video just black-n-white diagonal lines, anything with an audio amplifier in it only got our station. In fact most of the appliances sang, you could hear the high frequencies of the audio come from them. And just about anything metallic, if you touched it lightly with your finger you would get an RF burn.
Now we knew we weren’t anywhere near the legal field strength limits at this power level, however, since the fields were actually HIGHER outside a block away and there was no external antenna or other visible signs of the operation I figured that we were pretty safe but complaints from my mother, sister, and neighbors forced the shutdown of the big transmitter. We operated the lower power transmitter for a while, with less negative effects, the lights only mildly flickered with the modulation, the TV was watchable though it still had some bars through it, and you could still here our station in anything with an audio amplifier but at that power level it was in the background instead of the foreground.
With that setup we really found two major problems, for one thing we didn’t get good range because most of the RF power was eaten up heating light bulb filaments and the like rather than being radiated, and there are so many non-linear devices on the powerline that would cause intermodulation between the RF signal and the 60 Hz power, that at many locations there would be bad hum / buzz in the received audio. So this was a relatively short-lived experiment.
We also experimented with something called a ghost line. Apparently during world war I, enemies would cut telegraph lines, so a method was devised to send telegraph signals through the earth. At both ends, a couple of stakes would be driven into the ground several hundred yards apart with the line connecting them perpendicular to the direction the other station was in. Then a large power supply or battery bank would be keyed into the resistance between the stakes via a large but sufficiently fast relay.
At the receiving end, a sensitive relay would be able to get a portion of that current because the earth basically acted like a resistive network dividing the voltage. And so Morse code could be sent through the earth without the benefit of wires that could be cut by the enemy.
I thought it would be interesting to try this at audio frequencies, so I put two stakes about 100 feet apart in my yard, east-west, and used a PA line transformer to match the output of my Radio Shack STA-2000 stereo into the ground stakes.
Then I took a portable cassette recorder and connected a couple of wires with small stakes into the microphone input and walked north. With the stakes at the receiving end feeding the microphone jack of the cassette recorder only about six feet apart when I’d stick them in the ground, I was able to hear the audio up to two miles away. At two miles there was a lot of AC buzz competing with the audio. I had ideas that maybe I could get around the buzz and achieve longer distances by using an FM carrier at around 50 Khz or so. I figured between the noise reducing effects of limiting, and getting away from the 60 Hz area where the noise concentrated it might be workable. I attempted to build circuitry to do this but was never successful at getting it to work.
This was an era before PC’s existed, maybe just after the Altair computer kits and Commodore Pet hit the market. No Internet back at that time. I wanted to broadcast, but I couldn’t seem to find an effective way to do it legally. And nothing was the same as the old AM bootleg station.
There is something magical about AM, as if your voice not only goes out into space, but as if it’s actually transversing dimensions. It’s hard to explain, it’s something you have to feel. It’s organic. FM transmissions, today’s digital systems, technically they are superior but they are sterile, inorganic, the magic that is in AM is not there with these systems. The way you can receive AM stations from all over and even outside the country at night and one would fade in and out, you never knew, especially at night, where your voice was going.
And music… Not the same sound quality as FM, but again, it’s organic via AM, sterile via FM. Hard to describe what I mean by that, you’d have to have been there and done it.
And really that was a magic era in radio, radio is crap now, automated syndicated crap. The magic is gone. I’d kill for real shot at an opportunity to bring it back, well maybe not kill, but I can’t think of anything I’d rather do.