Bart and Bert used to go to Professor Ventura's lab quite often, staying there until very late at night, centred in a new project, or simply discussing current technology, mechatronics, computer science, nanotechnology, or just the "old" electronics.
At a specific night, that also happened, but an unforeseen event took our heroes to another exciting adventure. It was past 9 o'clock when Bart and Professor Ventura were working on setting up a new panel of logic circuits to use in mechatronic classes. Bert, who had already done his part, was getting distracted by "going through" the radio frequency spectrum with Professor Ventura's scanner.
The "scanner" was actually one of the lab's biggest attractions, or rather Professor Ventura’s. He had purchased the device on a trip abroad.
The "scanner" is a radio receiver which, as the name says, "explores" the radio spectrum, and when it finds a signal, it tunes in, and if we want, it "hangs" on the frequency, with a digital indication of what it is. Professor Ventura's ranged from 30 MHz to 900 MHz, almost continuously, which allowed him to hear practically everything that goes on in the ether.
From playing with the device, Bart, Bert and Professor Ventura already knew most of the transmissions and frequencies that could be received in Lemon city: the police station, the road station, the small airport, the local and nearby radio amateurs, some farms , old cordless phones, etc.
If there were some "different" transmissions, they would certainly recognize it immediately, even though Professor kept a detailed record, especially if the signal had something to differentiate it from all that is known, and that was just what happened a few minutes later!
- But... what is this? - Opening the volume, Bert drew attention to a strange signal he was listening to: it was an unrecognizable sound, something like a shuffled voice, similar to what happens with the scramblers, that is, devices which shuffle the voice in the confidential telephone systems .
- It really sounds like a "scrambler", but here in our town, no one has this kind of "thing"! Who could be using it? - The Professor stopped working and listened to the strange signal.
- For me it's a German trying to speak Russian, with a potato in his mouth!" - Bart's opinion gave an approximate view of what was being played on the small speaker of the scanner.
- What’s the frequency, Bert?"
- 42.625 MHz!
The Professor then wondered even more what was being picked up.
- This frequency is used by cordless phones, but in the types I know, that's not how the signal gets scrambled. You know, many of the most modern cordless phones have scramblers to ensure privacy. In fact, modern types are digital.
- Really, many people who use ordinary cordless phones and even analog phones forget that these devices are transmitters and therefore radiate their signals to anyone who wants to capture. I have heard of many problems created because of this.
Bert remembered a case that had occurred in that same city not long ago:
- I remember the case of that lady from the local high society who was talking about what she should and should not do on her cordless phone by the pool, and by coincidence, her neighbor also had a cordless phone that operated on the same frequency! Accidentally discovering this, the "other" began listening everything she said and in most of the conversations were opinions not very favorable about the "neighbor", that is, the one who heard everything!
- I also remember! - Bart confirmed - The case went to the police! While one alleged insults of all forms, the other claimed invasion of privacy!
Professor Ventura was the one who completed:
- I liked the opinion of the judge at the end of everything: if the signal from my neighbor's phone is irradiated and enter without my permission in my house and I capture it, I can do whatever I want with it! It would be characterized invasion of privacy if I were to get the signal in the neighbor's house, installing some type of interception device, for example, on the phone line ... Let this be an alert to those who say what they want, and without care, on cordless phones and cell phones ... There is always the possibility of someone listening!
But the strange sign still worried all the three of them: it was too strong to come from a cordless phone, and it was not like a dialogue where we have someone talking on one side with interruptions so that someone talks about the other.
It was a different broadcast!
Even exchanging ideas, they had time to tap the little old-fashioned tape recorder that was always in the lab and record a good part of this strange signal. Shortly afterwards, without any kind of warning, the strange transmission disappeared.
- I'm curious to know what that is. It deserves an investigation, doesn’t it? - The Professor winked at the boys.
In fact, the last few weeks had been very boring, both in terms of projects and of "trouble" in which they always got into, and there was the opportunity to get distracted.
- We can imagine that it is a "fox hunting", with the difference that we must also discover the content of the message! - Bart even imagined a kind of game, but what he did not know is that this strange transmission had a much more important content than a simple joke...
On the following day, Bart and Bert went to Professor Ventura's lab, excited about the challenge of discovering the origin of the strange transmission. The first step in figuring out anything about it was checking whether the transmission occurred frequently. Thus, by setting the scanner on that frequency, they took advantage of the squelch circuit to trigger the recorder, which would then record any signal at any time of the day or night.
The squelch is a feature that most telecommunication receivers have; it simply shuts off the audio section, cutting the nasty buzz between stations when no signal is being received.
Another interesting feature was added to the "electromagnetic surveillance" system, as they called it. Bert had an electronic watch which spoke up the time whenever a button was pressed.
The talking watch was initially a curiosity, but after his enthusiasm for its behavior had passed, he had made it an "accessory" to the lab's special electronic resources. He connected the button to a relay, and threw the audio output to a small amplifier that could either be used to drive a loudspeaker or an external circuit.
One of the applications which was given to this circuit was to demonstrate it in a science fair: the relay was in the exit of a VOX, that is to say, a circuit driven by voice or sounds.
It was very interesting to see the astonishment of the people who, clapping their hands or snapping their fingers in front of the Technical School booth, heard as an answer the right time! Even the "preboste" Saturn Spendthrift, who visited the fair, was impressed by Professor Ventura's ingenuity and suggested:
- I will propose the installation of a "thing" like this on our square!
(For those who do not know, the title of preboste was attributed to the local mayor - See the first adventure of Prof. Ventura on this site)
An advisor immediately wrote it down.
But in the case of the strange transmissions, what they did was to connect the scanner's monitoring circuit to the relay, and the output to a small mixer which connected the audio signal of the clock to the audio signal of the receiver. An intermediate timer on the clock relay allowed it to be triggered only for the period needed to the time warning once. This meant that by "entering" any signal on the scanner, the recorder was triggered, and at the same time a small beep was recorded with the time that this occurred.
- The surveillance system is ready. - commented Bart. - Now, while it does its service for a day or two we will review the contents of yesterday's recording!
The content of the tape a few minutes long was strange.
First they connected the output of the recorder to an oscilloscope to analyze the general pattern of the signal, since, as there was a constant variation of frequency and amplitude, it was not possible to speak about waveform.
Nothing different which could reveal a coding, but it was not a "noise" in which there is no definite pattern: a digital pulse, a repeating tone, or something. Afterwards they played the tape at several speeds, as it could have been an "accelerated" transmission. When Professor Ventura spoke about this possibility, Bert did not understand very well. The Professor explained:
- In espionage this technique of transmission is well known.
The secret agent records the message on a tape at normal speed, and then with a special recorder connected to a transmitter, it plays the tape at a much higher speed.
This way, not only listeners do not understand anything, but the transmission time is reduced, thus reducing the possibility of the transmitter being located. A message of 1 minute, for example, can be transmitted in 10 seconds!
- And then, to retrieve the message, just record it on an accelerated recorder and play the tape at a normal speed. Right? - Bart had understood well how it "worked".
But that tape was a mystery.
On the following day, checking to see if there was anything on the tape recorder, the three of them found the same broadcast exactly at the same time of the previous day! Waiting to arrive at the same hour, they verified the transmission of the strange sounds always occurred after 9am., on the same frequency and had approximately the same duration!
- The next step is to know where this signal comes from, since we still cannot decipher its content! - That said, the Professor went to his locker and returned with a directional antenna for the scanner.
- That will help a lot!
Just before 9 o'clock, when the signal should be received, Bart and Bert were already prepared with the scanner and the directional antenna. Professor Ventura's car was ready to follow the signal, no matter where it came from. All the three os them waited anxiously.
Exactly on schedule, the strange transmissions began: unintelligible sounds, without any interruption that characterized a dialogue or telephone conversation, but which reminded someone speaking ... Immediately Professor Ventura got into the car and started it. Bart and Bert settled in with the receiver and the scanner, moving the antenna they immediately found the direction from which the signal came.
Driving the vehicle and careful not to lose the signal, they traveled several streets of the city until they reached the uphill which passed in front of the cemetery and down the other side ended in Newville, a neighborhood far away from downtown.
- The cemetery! ... Not this one! Are these signs of the other world? - Bert did not like the idea of ??going to the graveyard, especially at that time of night.
- We aren’t going through with this, are we?
- Really? Are you that scary? Nothing indicates this sign comes "from" the graveyard, but rather "from its direction"! It can come from somewhere "behind" or even "beyond" the cemetery, on the other side of the hill for example, from Newville!
- Yes, but it may come from the other side of the graveyard itself or from the “beyond" itself and to make sure we have to cross it!
The two boys made a face like they were going to start whining.
Going up the slope, however, the signal got louder and louder.
But what frightened the three was the peak, which occurred just as they passed the graveyard gate, with the antenna facing it! The Professor stopped the car!
Bart and Professor Ventura looked at Bert and did not say anything. After some time it was the Professor who said:
- Very well! Who is going to go down and explore the signal inside?
- I will not!
- Not me!
The Professor was not cheerful, and getting out of the car, he studied the inside of the graveyard carefully, looking for something different. Then, he returned and starting the car he muttered:
- You cowards!
Bart and Bert did not say anything.
Back in the laboratory, Bart decided to ask the Professor about his excuse:
- If we are cowards, why didn’t you Sir enter the cemetery alone when you got out of the car?
Professor Ventura swallowed, trying to disguise his fear a little, but he had a good way out of the embarrassing situation:
- I did not go in because I was without proper equipment. I came back so we can get better prepared. Tomorrow we will have everything: lanterns, boots, and everything else the exploration of an adverse environment demands!
- Including a crucifix to ward off vampires and an anti-ghost spray! - Bart joked.
Bert, who was more afraid, tried to laugh, but he was, in fact, terrified of the idea of ??"invading" the cemetery the following night, even if only to go after a radio signal!
The following night, just before nine o'clock, everyone was prepared to follow the signal, but this time in a slightly different way. All three looked like they were going on a hunt into the wild in Africa, that’s how much equipment they had! After all, "invading" a graveyard at night was a task for Indiana Jones and they were simple "mortals": they needed to be properly equipped!
At the scheduled time the transmissions began, and all three were already in the vehicle with the engine warmed. This time, it was not necessary to go around very close to the graveyard where the signal was once again stronger. Bart commented as they were passing by:
- Let's walk! The noise of the car can alert those operating the transmitter!
- It's time to walk on eggshells - was Bert's way of showing he needed to be careful and was afraid.
- Let’s go! - said Professor Ventura, already with his equipment on his back. Bart held the scanner at a reduced volume, while Bert wielded the antenna.
Bart advanced, but Bert was reluctant.
- What's the matter? Are you scared? - Bart asked his friend.
- I am not! It's just my legs… they want to go home!
Bert did not find it very funny, especially because he was in no position to make fun of his friend, since he was as afraid as Bart.
- Let's go! - insisted the Professor. The three advanced cautiously ...
Opening with a threatening squeaking, the heavy gate of the cemetery, which was never locked by order of Saturn Spendthrift, the mayor, (after all, he said, whoever is inside cannot leave and whoever is outside doesn’t feel like entering!). The three entered.
There was a moon, but a few black clouds capped its light, leaving the place dark. In the distance, some clouds were illuminated by lightning, from a storm not far away, making the environment even more menacing. There was no doubt the three were afraid, but they still tried not to show it!
Bart, for greater security, lowered the volume of the scanner and placed it close to his ear. Whispering he would guide his friends to where they should go, depending on the strength of the signal.
- Over there, but be careful! It is getting stronger!
Advancing very cautiously, stumbling over some graves and loose stones, the signal grew louder until Professor Ventura abruptly stopped and advised silence:
- Listen! Aren’t you hearing anything from there? - and pointed to the direction of a large chapel-shaped tomb.
It seemed that there was a dim light from inside and the door was open. Bert began to tremble. Bart, shortly commented:
- I can not hear anything, and I cannot see it. Are you afraid of what?
Bert still had time to make jokes:
- My friend, if you had seen something, it would be very good! In a place like this, I'm afraid of what I can’t see and what I can’t hear!
- Shh! Listen ... - he motioned with his hands, as soon as the two boys understood, Professor Ventura got down. Bart and Bert, too.
From the spot pointed by the Professor came a diffused light and, paying attention in silence, they could hear a certain noise.
- What is that noise? - asked Bert, startled.
- It must be your heart beating with fear! - commented Bart.
The Professor interfered:
- Silence boys! Let's get closer!
Very carefully, putting out the flashlight, and with the scanner turned off they approached the place and what they saw was interesting; they were not ghosts, not skulls, but very "living" people. Two figures left the tomb, one carrying a box and the other a flashlight. After carefully closing the door of the tomb, the two of them headed toward an opening in the wall of the cemetery where they disappeared.
A few seconds after that, Professor Ventura, Bart, and Bert could hear the muffled sound of a car moving away quickly. There was a trail behind the graveyard on the highway. The signal had already completely disappeared when this occurred.
- Well, look! This is stinking more than it should! - commented Professor Ventura.
- It is! - Commented Bart - Let's see this up close!
Although Bert did not like the idea, the three of them approached the tomb door carefully.
- It's locked! We need to open it!
The Professor then opened his utility bag and taking out a "clamp" forced the padlock. Opening the door he ordered:
- Let’s get in!
- You are crazy! - cried Bert, trembling.
- Okay! So, you keep watching out here and I'll get in with the Professor!
The idea of ??being alone out there and in the dark was worse than entering! Bert did not even let his friend finish:
- No! I will go together!
Slowly, and very carefully, the three of them entered the dark tomb!
It was a parlor, indeed a chapel, and there was, at the bottom, a door in which the compartments with the coffins would surely be, and before which the three of them stopped.
- Open it! - commanded Professor Ventura.
- Not even if I were dead! - Bert protested once more.
- It's ok! - Bart, braver but still afraid, went to the door and carefully opened it. Illuminating the interior with the light the three of them had a huge surprise!
No, it was not a ghost, a mummy, or some otherworldly thing, but several boxes packed with words in English and some oriental language on the corner of a little table with a transmitting radio! From the transmitter they could see the wire coming out of an opening, and it would certainly lead to an antenna hidden somewhere!
On the corner, there was a 12V battery of the type used in cars, and that certainly was to power the device. Certainly, every time it was discharged, those responsible for all this replaced it with another loaded!
- What the hell are these packages?
Professor Ventura then examined one of them very carefully and discovered:
- Electronic components! "Chips" of computers, memories, CPUs, micro-controllers, development boards! ...
- This is a gold mine!
For those who are in electronics "to the bones" like them, it was certainly a gold mine.
- No! Smuggling! - exclaimed Professor Ventura. - Let's get out of here and tell the police, we can arrest all of them!
The three of them hurried out of the compartment and wanted to move quickly away from the place, even though the individuals who had been seen leaving the tomb could return at any moment. However, it was at that moment that, with a scary noise, a crate (which looked more like a skiff) which was misplaced, when it was touched by Bert, collapsed and a skeleton practically "hugged" the boy!
It was a "natural" fluorescent plastic skeleton that one of the smugglers had brought "to scare off intruders," but it was not used, for it would certainly serve more to attract attention!
The boy, terrified, ran out and shouted towards the car with the "skeleton" hanging, for it got caught on his clothes, and as he left the graveyard "at speed," an even bigger problem:
Coming back from another performance of the band which played in the bandstand until 10 o'clock, there was Tubald, walking quietly, but not without fear, especially as he passed the cemetery, holding his gleaming tuba! It was the point where he stopped whistling Sousa's marches, hurried on his steps and was afraid, clutching his instrument! What kind of protection a tuba could give someone, we do not know, but this gesture worked as a kind of "psychological support."
Tubald lived in Newville and wanted to get to his house quickly as it threatened to rain! Some thunder was heard in the distance. Passing through the terrified gate, Bert had a minimal chance of bumping into someone at that time, and especially with a tuba, but according to Murphy's law, if something wrong can happen, it happens ... Bert came right into the arms of Tubald, who gave a terrified shout.
- Aww!
As he was also surprised, Bert gave his terrified cry:
- Ohh! ...
We do not know if what frightened Tubald was the sacarry look on Bert’s face or the skeleton that in the impact was released and "grabbed" the musician’s tuba, stuck in the gleaming instrument! At that moment Tubald was still astonished at the audacity of that "fleshless creature" which was trying to snatch him from his precious tuba! For a moment he doubted whether he would let his tuba go and run or ask the squalid "haunt" to retrieve his precious instrument being grabbed by a ... "soul of the other world"!
However, in the unusual situation the short and chubby musician did both: he did not give up his precious tuba and also ran! And off he went... It would be very difficult to describe the dreadful look on Tubald’s face as he went down the hill, clutching his tuba, swinging all his bones and snapping the fluorescent skeleton sounding like a chestnut being cracked!
The fact is that when Bart and Professor Ventura arrived at the gate, Bert ran far down the hill towards the city and the poor Tubald with his tuba and the skeleton made the curve of the slope in the opposite direction towards Newville, in total despair!
- We're going to have to go to the police early in the morning, because Tubald will certainly “spill the beans” - Said the Professor, getting into the car.
- And he has a reason to know it was us! My car is very visible nearby! Not to mention the poor Bert! - said the Professor.
Bart went to Bert's house, finding his friend still half panicked and panting.
- Are you all right?
- Yes! Just a little frightened - commented Bert
- A little? If you always ran like this, our school would win gold in all high school games!
- It's ok! I was tense, and that "thing" scared me!
Bert did not want to pronounce the word "skeleton" because someone in his house could find out where he had been!
- It was in fluorescent plastic, didn’t you see how it glowed in the dark?
- Was it? Really? And only now you tell me?
- I told you right away, but you were about five miles away! You couldn’t hear me!
Calmer, Bert changed the subject and decided to comment on the finding:
- Wow! If we can decipher those recordings we can find out a lot of interesting things!
- Wait! Did you try to pass that tape backwards but slowly?
- No? Why?
- That's the only thing we didn’t do, and it's going to be the first thing we'll do tomorrow morning! I have a hunch I discovered a way to know the content of that recording.
Bart was right!
The next morning, early on, Bart and Bert were at the door of Professor Ventura's house, already preparing to leave for the police station. Bart quickly explained his idea of playing the tape "in reverse."
- Wow, that could be it! - commented the Professor - Let's see now!
In the lab what they did was simple, as the tape recorder was of the old "roll" type, they swapped the rolls of magnetic tape and played them with changed speed and what was heard was very interesting:
- ... and in the next shipment send more memories of 256 GB, and processors of 512 GB. I have a customer that needs them! Send at least 1,000 of each ... - and the clear conversation indicated contact with a supplier somewhere, "on the other side of the fountain" ...
- Let's take this tape… to the police station! The Delegate will like to hear this!
At the police station, Chief Marins, who knew the professor very well, since his son was also a student at the Technical School and had even asked for help in previous "technical problems", received it very well, actually better than he should:
- Hi, Professor, how was your ride last night?
The Professor swallowed dryly with Bart and Bert and thought to himself:
- Devil, Tubald has already been here and the Chief knows everything!
- All right, we came here to tell you everything that happened last night! We have a great explanation for everything, and more than that, things you should know!
The chief of the police station, half sarcastically told them to sit down and commented:
- You sure do, Professor Ventura! You sure do! ...
The Professor said everything that had happened, the capture of the strange signal, the investigation that led them to the cemetery, what they saw in the tomb, the skeleton “hugging” in Bert and the "bump" with Tubald! Finally they showed the recordings, which included contacts of "orders" from several days.
- And the "electronics" gang! - exclaimed the chief in surprise. - We had already been warned that there was a smuggling route here, but no one has ever discovered anything! I think that with the help of you we can catch them!
- We can get them! - warned the investigator Sampaio who was next to them!
- Let's go! - the Chief went further and, standing up, invited everyone to accompany him.
The group then went to the cemetery where Professor, Bart and Bert were to show the Chief the place of the "tomb" used as a hiding place!
- So this is where you guys go "strolling" at the late hours at night! - the Chief said, as the investigator carefully opened the door to the tomb.
The Chief and the investigator examined everything carefully. They decided to set up a "trap" to catch the smugglers that night.
- Then they broadcast every day at the same time! We can get them in action! - commented the Chief.
The Professor confirmed:
- Yes that's right!
- But, tell me Professor, how, that they made such a "codification" of the message so that nobody understood what they talked about?
The Professor, now more at ease explained:
- They previously recorded the message on a tape and then to transmit, they used a recorder that turned it "upside down" and at high speed, which allowed to "contract" the transmission time and still obtain an inintelligible sound if someone intercepted.
- Ingenious! - commented the Chief, who liked technical things, especially when linked "to crime"! - Continue!
- Well, at the reception site, it was enough to record the sounds that became incomprehensible and then pass the tape "in reverse", but at a slower speed. That's what we did and the message became clear!
- You guys are too smart! How did you suspect that this was the kind of "coding" used?
Trying to value the work of the group, the Professor concluded:
- For "experts" like us, signal analysis has revealed this easily!
The Chief thanked him and said he would come back with new information about the bad guys.
In fact, the next day, the movement in Lemon city was above normal, especially at the door of the police station where several vehicles coming from neighboring cities brought "police reinforcement".
A federal police vehicle called attention, because it was within its competence the crime of smuggling.
At night nobody knew anything, but the few people who wanted to pass before the cemetery were cordially invited to change course, by some policemen without uniform placed in strategic points. The next day the whole city learned of what had happened, and even more so, Professor Ventura, Bart and Bert who were called to the police station:
- We got the smugglers! With his information we surround the group of the tomb and from it we intend to reach the others! They used the tomb as a point to transfer goods and contacts! The fixed transmitter facilitated the orders, since they did not worry about suspicious equipment nor transmitted from an easily locateable place!
- Wow! They didn’t count on our skills! - commented Professor Ventura proudly.
- Great skills, no doubt! - commented the Chief.
The Professor, Bart and Bert were about to leave when the Delegate prevented them:
- Hold on! The "thing" is not over for you!
Worried, the three of them looked at each other and soon thought that they would have to hear a nice "scolding" for the "walk" in the cemetery, but that was not quite it:
- You owe a compensation to a person "injured" in this business of yours! ...
- Compensation? - The Professor did not know what he was about.
- Yes, you owe two new "doors"!
The Professor scratched his chin and said,
- But what doors? We didn’t break the graveyard door or the graveyard gate!
Bart, without disconnecting himself from the electronics, still thought about the possibility of having "damaged" some logical "ports" of integrated circuits or computers, when they moved the merchandise hidden in the tomb:
- Serial or parallel? - the boy asked, still confused.
- Not at all! I do not know what that is, but I'll explain!
The Chief then gave the complete information:
- You didn’t break anything! But Tubald ...
The Professor then put his hand on his head in oblivion and said,
- Wow! I completely forgot about the "poor guy"! Let's immediately apologize for the situation!
The Chief again insisted:
- Not excuses, two doors!
-?
In order for the readers to have a better idea of ??what the Chief was saying, it is interesting to go back a bit in time, and describe what happened to the "poor" musician and his tuba from the moment the skeleton curled up on his tuba :
Tubald was so terrified of the skeleton twisted on his tuba that he entered his house without opening the door, simply "crossed it" and, likewise, went to the room, where again without opening the door, crossing it, he "stuck" himself under the bed.
Mrs. Wheathercock, due to the noise and the confusion "armed" herself with a broom and went to the after whatever it was that scared her husband!
After three brooms bronked on the skeleton, two on the tuba and one on Tubald’s head, she managed to "dominate" the situation! Even taking some painkillers, the poor man still could not sleep and the next day, very early, went to the police station where, more yellow than his tuba, told a "confused" story of a boy who seemed to be Bert, desperately running away from a “flaming” skeleton. The skeleton, however, instead of grabbing the boy, had opted for his tuba.
In the face of the fact, he would never abandon his faithful tuba, and then he ran! This was the "story" that the Chief also told the Professor. Professor Ventura, Bart and Bert could not help themselves and started laughing out loud.
It was the Professor who spoke first:
- It's ok! It's ok! Let's go to Tubald’s house to tell him the whole story and let's "pay" two new doors!
- But what about the skeleton? - Bart asked interested about it.
Lifting the strange object behind the table, the Chief presented it triumphantly to the three of them.
- This one?
Apologizing, the Professor then asked:
- What do you intend to do with it, Sir?
The Chief, staring at the "eyes" of the squalid creature, replied thoughtfully:
- I have nothing in my mind!
Professor Ventura then suggested that it would be donated to the anatomy department of the Technical School, as it could be used for studies, even if it was artificial.
The Chief, giving the object to the Professor, established a condition for this:
- Yes, it may be, but in one condition: that you do not think of taking it for a walk in the cemetery, especially at night and even so when Tubald returns from his performances!
Everyone laughed…