HackerBox 0130: Shortwave

Welcome to HackerBox 0130. Get ready to explore shortwave radio and related matters such as skywave propagation, band plans, operation schedules, and numbers stations. Leverage a highly-integrated, mixed-signal, single-chip receiver capable of operating on four different radio bands, including 6-18 MHz shortwave frequencies. Understand the advances in RF-CMOS technology that enable the high levels of integration necessary for compact modern wireless equipment including mobile smartphones and satellite radios. Explore the relationship between frequency and wavelength of radio waves as well as antenna geometries. Discover the history of HF band radio communications, the significance of the amateur radio hobby, and how to become a licensed amateur radio operator. Modify the quad-band receiver to operate with an external antenna. Prepare a field antenna accessory kit with items useful for assembling and connecting improvised antennas during field operations. Implement a long-wire dipole antenna and assemble a popular end-fed, half-wave antenna kit. Test a simple tiny passive donut antenna and assemble an exclusive, actively-amplified magnetic loop antenna. Understand how all microcontrollers just might be radios in disguise and how that notion relates to electromagnetic interference. Leverage advanced hardware timer trickery on an EPS32-C3 microcontroller to bang out pseudo-RF signals despite the MCU's lack of digital to analog converters. Discover the fundamentals of RF Black Magic including the development and use of the Smith Chart. Explore free educational resources found all across the Internet.

The various antenna implementations presented in this HackerBox guide can be used with other radio receivers, including increasingly common software defined radio (SDR) receivers. A novel example of which just might be encountered in an upcoming monthly HackerBox - no spoilers!

There is a wealth of information for current and prospective members in the HackerBoxes FAQ. Almost all of the non-technical support emails that we receive are already answered there, so we'd really appreciate it if you can take a few minutes to read the FAQ.

This Instructable contains information for getting started with HackerBox 0130. The full box contents are listed on the product page for HackerBox 0130 where the box is also available for purchase while supplies last. If you would like to automatically receive a HackerBox like this right in your mailbox each month, you can subscribe at HackerBoxes.com and join the party. Subscription members save at least $15 every month and automatically receive each new HackerBox shipped immediately off the production line.

A soldering iron, solder, and basic assembly tools are generally needed to work on the monthly HackerBox. A computer for running software tools is also required. Have a look at the HackerBox Workshops for tools and supplies along with a wide array of introductory activities and experiments.

The most import thing you will need is a sense of adventure, hacker spirit, patience, and curiosity. Building and experimenting with electronics, while very rewarding, can be tricky, challenging, and even frustrating at times. The goal is progress, not perfection. When you persist and enjoy the adventure, a great deal of satisfaction can be derived from this hobby. Take each step slowly, mind the details, and don't be afraid to ask for help.

WEAR SAFETY GLASSES WHEN SOLDERING, WHEN TRIMMING WIRE LEADS, OR WHEN CUTTING, DRILLING, ETC.

The Radiodog video embedded above addresses the question of WHAT IS SHORTWAVE RADIO?

The follow up video addresses the question of WHAT'S ON SHORTWAVE RADIO?

Shortwave Radio (Wikipedia) refers to radio signals found in the shortwave bands (SW). There is no official definition of the SW band frequency range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (approximately 100 to 10 meters in wavelength). It lies between the medium frequency band (MF) and the bottom of the VHF band.

Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" propagation. Thus shortwave radio can be used for communication over very long distances, in contrast to radio waves of higher frequency, which travel in straight lines (line-of-sight propagation) and are generally limited by the visual horizon, about 64 km (40 miles).

Shortwave Listening (Wikipedia) is also known as SWL. It is the hobby of listening to shortwave radio broadcasts located on frequencies between 1700 kHz and 30 MHz. Listeners range from casual users seeking international news and entertainment programming, to hobbyists immersed in the technical aspects of long-distance radio reception and sending and collecting official confirmations (QSL cards) that document their reception of remote broadcasts (DXing). In some developing countries, shortwave listening enables remote communities to obtain regional programming traditionally provided by local medium wave AM broadcasters. In 2002, the number of households that were capable of shortwave listening was estimated to be in the hundreds of millions. As of 2025, it is estimated there are at least 600 million shortwave radio sets worldwide.

The What's on Shortwave video touches on some useful and interesting topics including Shortwave Schedules as well as Shortwave Bands.

Numbers Stations (Wikipedia) are also mentioned. A numbers station is a shortwave radio station broadcasting formatted numbers, which are addressed to intelligence officers operating in foreign countries. Numbers stations have been documented since at least World War I and reached peak activity during the Cold War. Messages are typically encrypted using a one-time pad, a method considered theoretically unbreakable when applied correctly. Since shortwave signals can propagate over intercontinental distances by reflecting off the ionosphere, a single transmitter can reach agents worldwide. The receiving agent requires only an ordinary consumer shortwave radio, possession of which carries a degree of plausible deniability. These properties, combined with independence from satellite and internet infrastructure, have led analysts to argue that numbers stations retain operational relevance even in the 21st century. For example, watch the video below about the US-Iran War.

Numbers Station Videos:

1. Secret Numbers Stations and How To Listen
2. The Mysterious Phenomenon of Numbers Stations
3. Mysterious Radio Signal From Day One Of US-Iran War

Owning a shortwave radio in Russia may once again be a subversive activity.

This quad-band receiver is based almost solely on the KT0936MB9 single-chip radio receiver. The datasheet for the KT0936MB9 integrated circuit chip is attached below.

As shown in the schematic above, four selection resistors configure the receiver to operate on four bands:

1. FM: 87 - 108.5 MHz (configured by R1 = 63.4 Ohm)
2. MW: 513 - 1629 KHz (configured by R4 = 787 Ohm) - traditional broadcast AM radio
3. SW1: : 5.75 - 12.15 MHz (configured by R6 = 15.4K Ohm)
4. SW2: 12.95 - 18.05 MHz (configured by R5 = 169K Ohm)

The KT0936MB9 single-chip receiver can operate with no external filters or frequency adjustment circuits. The architecture includes an on-chip microcontroller, a fully integrated low noise amplifier, automatic gain control (AGC), a series of high performance analog to digital converters (ADC), high performance analog and digital filters, an on-chip low noise automatic tuning voltage controlled oscillator (VCO), and an accurate and automatic antenna tuner operating over a wide frequency range. The KT0936MB9 also features a built-in Class AB audio amplifier.

OPERATION

There are two switches, both are 2P3T. A 2P3T switch is short for 2 Pole, 3 Throw, which means that the switch controls two separate paths and lets each path connects to one of three different pairs or positions.

The switch on the left has three states: OFF, FM, and AM. The second switch only matters when the first switch is set to AM (amplitude modulation, not to be confused with the traditional broadcast AM radio band). The second switch then selects between the three amplitude modulated bands: MW (traditional broadcast AM radio frequencies), SW1, and SW2.

TRULY NEXT-LEVEL INTEGRATION

The KT0936MB9 single-chip receiver is a mixed-signal integrated circuit, which means that it features both analog circuits and digital circuits on a single semiconductor die. Amazing advancements in these RF CMOS (Radio Frequency Complementary Metal Oxide Semiconductor) chips have come about thanks to enormous modern demand for cell phones, telecommunications, portable electronics, and automobiles with electronics and digital sensors.

This video very nicely documents the impressive advancement and quizzical future of RF CMOS. Silicon's rapid rise in Radio Frequency (RF) applications is a lesson in the power of Moore's Law. Over twenty years ago, all the parts of a radio's RF front end module were made separately and integrated into a bulky enclosure. Highly integrated silicon solutions have changed that making possible today’s slick and thin cellphones and other mobile wireless communication devices.

Radio Bands (Wikipedia) are sections of the electromagnetic spectrum used for wireless communication, spanning from 3 kHz to 300 GHz. They are categorized by frequency and wavelength:

1. VLF & LF (Very Low & Low Frequency): 3 kHz – 300 kHz; used for submarines, time signals, and navigation.
2. MF (Medium Frequency): 300 kHz – 3 MHz; used for AM broadcast radio (535 kHz – 1.7 MHz).
3. HF (High Frequency): 3 MHz – 30 MHz; known as SHORTWAVE RADIO, used for global and amateur (ham) radio.
4. VHF (Very High Frequency): 30 MHz – 300 MHz; used for FM radio (88–108 MHz), aircraft communication, and weather radio.
5. UHF (Ultra High Frequency): 300 MHz – 3 GHz; used for TV broadcasts, GPS, Wi-Fi, Bluetooth, and cellular phones.
6. SHF & EHF (Super & Extremely High Frequency): 3 GHz – 300 GHz; used for satellite communications, 5G data, and advanced radar.
7. LHF (Ludicrous High Frequency): Spaceballs.

The blue highlighted section in the image above shows how the frequency and the wavelength of a radio wave always multiply together to equal a constant c (the speed of light). Accordingly, the higher the frequency, the shorter the wavelength. This will be presented visually in the RF Black Magic video that we'll be watching later. Note that wavelength is very often represented by the lowercase greek letter LAMBDA.

From the wave speed equation, we can calculate that waves in the lower HF frequencies (3 MHz) are around 100 meters long. They are said to be in the 100 meter band. Waves in the higher HF frequencies (30 MHz) are around 10 meters long. They are said to be in the 10 meter band.

RADIO BANDS AND ANTENNA GEOMETRY

The HF/Shortwave bands cover 10-100 meters. Very generally speaking, a simple antenna that resonates with a particular radio wave will be half as long as that radio wavelength - or radio band. Thus a simple dipole antenna operating in the 10 m band will be roughly 5 m in length and a simple dipole operable in the 100 m band will be roughly 50 m long. Here's a handy calculator. Take a look at two wave animations for the dipole antenna and appreciate how these relate to vibrations on a guitar string.

HISTORY BREAK

The video entitled, Where Did All the Ham Radio Operators Go? tells the fascinating story of how the sinking of the Titanic exposed the dangers of uncoordinated radio traffic causing Congress to enact the Radio Act of 1912 as the first federal law to regulate the electromagnetic spectrum. The Radio Act, banned Amateur Radio Operators from the primary commercial and military wavelengths, exiling them to HF frequencies which were then considered useless for long range communication. Confined to those supposedly worthless frequencies, they experimented relentlessly. Within a decade, amateur operators discovered the phenomenon of ionospheric skip, proving that SHORTWAVE SIGNALS could bounce off the upper atmosphere (ionosphere) and travel thousands of miles. The frequencies the government had dismissed as garbage turned out to be the most powerful long range communication tool on the planet.

In 1914, an inventor named Hyram Percy Maxim realized that messages could be systematically passed over vast distances if relay stations were properly organized. He founded the American Radio Relay League (ARRL), an organization that rapidly became the institutional backbone of the amateur radio community. Over a century later, the ARRL remains instrumental to this day.

HAM RADIO LICENSING - THAT'S THE TICKET!

Are hackers the future of amateur radio? You may want to consider getting an amateur radio license. It's probably easier, and more fun, than you think!

In the US, the initial radio ticket is the Technician Class License. It is obtained by passing a 35 question exam that, while not trivial, is easy enough to prepare for. All of the possible test questions are available free online to study at your leisure. Then you can find an exam session in your local area or online. Unlike the "old days" you will not be tested on morse code.

FREE EXAM PREP RESOURCES

HamStudy.org: online study materials and practice tests

PDF copy of the No-Nonsense Technician Class License Study Guide

FREE VIDEO COURSES

Note that (as of August 2026) neither of these playlists have been updated for the July 2026 test pool changes, so you will want to also review the specifics of those changes...

ARRL Technician Course 2022-2026 Playlist (37 videos)

Ham Radio Crash Course Technician License Prep 2022-2026 Playlist (12 videos)

RADIO CLUBS

Ham Radio Village, K0HRV

Find a Club

Pulling in (receiving) shortwave radio signals is not always the easiest thing to do. This list of English-Language Shortwave Frequencies Audible In North America starts out with some quick shortwave listening tips.

The quad-band receiver uses whatever wire is plugged into the headphone jack as its FM band antenna but it has a small ferrite coil antenna for the three AM bands. The ferrite coil antenna is the black, rubbery cylinder/dumbbell located at the upper left corder of the receiver.

We can replace the small ferrite coil antenna with a coaxial connector to allow the connection of external antennas. We will be using an SMA-F Edge Launch Connector. Note that there are TWO of these SMA-F Edge Launch Connectors. One is used here, and one is used later for the Magnetic Loop Antenna Kit.

MOD THE QUAD:

1. Remove the two AA batteries.
2. Remove the two small black screws fixing the batter holder to the PCB.
3. Lift the coil antenna slightly away from the PCB.
4. From the back (green side) of the PCB, locate the two solder points for the coil.
5. Heat the two solder points while GENTLY pulling the antenna from the PCB.
6. Solder two short pieces of wire into the holes left behind by the coil removal.
7. Those wires should extend from the front (tan side) of the PCB, not the rear side.
8. Note how the SMA-F connector has four rectangular outer posts and one round center conductor.
9. Snap off three of the four rectangular posts.
10. Working on the front (tan side) of the PCB, solder the wire closest to the PCB edge to the coaxial center pin as shown. Trim the wire as necessary - it should be VERY short.
11. Solder the other wire (closest to the trim pot) onto the one remaining rectangular post as shown. Trim the wire as necessary.
12. After testing the connection, cover the wires and base of the connector with hot glue, epoxy, or some other solid, non-conductive potting compound. This will act as a strain relief to protect the new SMA antenna connection while tightening an antenna or feed line to it.

While shortwave antennas can be used indoors, it's even better to make like Hacksquatch and get out into the field. Take a look at Field Day, SOTA (Summits on the Air), IOTA (Islands on the Air), LOTA (Lighthouses on the Air), COTA (Castles on the Air), BOTA, and Boy Scouts JOTA (Jamboree on the Air).

Our Field Antenna Accessory Kit includes some useful items for assembling, deploying, and connecting improvised antennas in the field...

1. BNC to Dual Binding Post Adapter
2. BNC-Female to SMA-Male Coaxial Adapter
3. BNC-Male to SMA-Female Coaxial Adapter
4. SMA RG174 One Meter Coaxial Cable
5. Two Large Red and Black Alligator Clips
6. Two Dual-Clip Insulator Carabiners

Among various other applications, the large alligator clips are useful for clipping onto the builtin antennas of commercial receivers where you might not want to rip out the factory antenna as we did with the quad-band receive.

DIY Shortwave Antennas (video)

Simple Shortwave Antenna Build (video)

A Look at the SpoolTena (video)

ADDITIONAL VIDEOS OF FIELD RADIO ACTIVITIES

Ham Radio Field Day Remains Relevant in 2026

Crashing Four Ham Radio Clubs For Field Day

JOTA - Get the Kids on the Air

Wolverines!

Loop Antennas (Wikipedia) consist of a loop or coil of wire, tubing, or other electrical conductor. In this case, the conductor is a PCB trace.

Small loop antennas, also called magnetic loops or tuned loops, have a perimeter smaller than half the operating wavelength. As with all antennas that are physically much smaller than the operating wavelength, small loop antennas have small radiation resistance which is dwarfed by ohmic losses, resulting in a poor antenna efficiency. They are thus mainly used as receiving antennas.

Small loops have advantages as receiving antennas at frequencies below 10 MHz. Although a small loop's losses can be high, the same loss applies to both the signal and the noise, so the receiving signal-to-noise ratio of a small loop may not suffer at these lower frequencies, where received noise is dominated by atmospheric noise and static rather than receiver-internal noise. The ability to more manageably rotate a smaller antenna may help to maximize the signal and reject interference.

Small loop antennas are popular for radio direction finding, in part due to their exceedingly sharp, clear "null" along the loop axis: When the loop axis is aimed directly at the transmitter, the target signal abruptly vanishes.

This Magnetic Loop Antenna incorporates a simple active amplifier circuit.

PARTS LIST:

1. Exclusive Black Magnetic Loop Shortwave Antenna PCB
2. NE592N8 DIP8 Amplifier Chip (datasheet)
3. DIP-8 Round Hole Chip Socket
4. SMA-F Edge Launch Connector
5. 1N4007 Axial Lead Diode
6. 5mm Red LED
7. 2K Ohm RV09 Potentiometer
8. 0.1 uF "104" MMCC Capacitor
9. MSK-22D18 6PIN Slide Switch
10. THREE 4.7 KOhm "4701" SMD-1206 Resistors (marked with ORANGE highlighter)
11. TWO 2 KOhm "202" SMD-1206 Resistors (marked with GREEN highlighter)
12. 9V Through Hole Battery Holder
13. Hardware (TWO M3 Machine Screws, TWO M3 Hex Nuts, and FOUR M3 Flat Washers)

ASSEMBLY:

1. Solder the TWO "202" 2K Resistors (marked GREEN) into positions R1 and R2
2. Solder the THREE "4701" 4.7K Resistors (marked ORANGE) into positions R3-R5
3. Solder the black axial lead diode at position D2 - be sure to line up the stripes
4. Solder the "104" 0.1uF MMCC Capacitor at position C1
5. Solder the DIP-8 Chip Socket at position U1 - match up the half-circle notch with the PCB marking
6. Solder the Red LED at position D1 - the short pin (cathode) goes into the hole with the square pad
7. Solder the power switch at position SW1
8. Solder the SMA connector - match the 3 central terminals to the 3 solder pads on the top of PCB
9. Solder the gain potentiometer at position R6
10. Solder the 9V battery holder onto the back side of the PCB
11. Carefully insert the NE592N8 amplifier chip into the chip socket matching up the notch
12. Cut about 60 inches of 12 or 14 gauge solid copper wire
13. Strip about one inch from each end of the wire
14. Form the wire into a large circle and form small end loops at each stripped end
15. Use the M3 hardware to tightly bolt the small end loops onto the top of the PCB

NOTES:

Using solid (not stranded) copper wire for the antenna allows the loop to keep its shape and rigidly stand up.

The wire can be bare copper, but there is higher chance of bare wire shorting against something, so wire with nonconductive insulation is a better choice.

Solid 12 and 14 AWG copper wire is commonly used in NEC compliant wiring, so it should be easy to find some lying around in scrap, or inexpensively purchased at any hardware store. Look for THHN/THWN solid wire or a scrap of white or yellow Romex (nonmetallic-sheathed NM) cable that you can pull the individual wires from.

Use needle nose pliers (or the bending hole of a wire stripper tool) to form the small loops at each end of the wire large enough so that an M3 bolt can fit into the small loop, but small enough that an M3 flat washer can capture the small loop against the PCB.

The design and operation of this antenna is similar to an Active Hula Loop Antenna.

The battery should last for 30-50 hours of operation.

This End-Fed Half-Wave Wire Antenna Kit was originally design by QRPGuys.

Prior to shutting down in 2026, QRPGuys were a well-known group of amateur radio operators and designers who created affordable, innovative low-power (QRP) radio kits and accessories.

When QRPGuys shut down, a full archive of their documentation was preserved at QRP Builder. You can find some pretty cool gear on that site as well as all of the Archived QRPGuys Assembly Manuals - including the manual for the original End-Fed Half-Wave Wire Antenna Kit, which is also attached below in PDF format.

Wait... Is that a HackerBoxes T-Shirt right in the front row of the audience?

Charles Lohr demonstrates how almost any microcontroller like an ATTiny85, ESP8266, CH32v203, or ESP32-S2 can be turned into a radio transmitter. He shows how to use the I2S bus on an ESP8266 to transmit NTSC color video to a TV and then how he was able to use an ESP32-S2 to transmit LoRa over 2.5 miles away. Finally, Charles shows how the CH32v203 microcontroller can also be used as a receiver. With some code he wrote, he is able to display the received signal on an FFT computed directly on the CH32v203, and even have a web interface to tune to specific frequencies and playback AM audio. (RTL-SDR.COM)

Not to be confused with... Electromagnetic Interference or EMI (Wikipedia) which is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction. The disturbance may degrade the performance of the circuit or even stop it from functioning. In the case of a data path, these effects can range from an increase in error rate to a total loss of the data. Both human-made and natural sources generate changing electrical currents and voltages that can cause EMI: ignition systems, cellular network of mobile phones, lightning, solar flares, and auroras (northern/southern lights). EMI frequently affects AM radios. It can also affect mobile phones, FM radios, and televisions, as well as observations for radio astronomy and atmospheric science. EMI can be used intentionally for radio jamming, as in electronic warfare.

The RISC-V ESP32-C3 is an interesting candidate to bang out some pseudo RF signals. While it is pretty speedy for a microcontroller, it does not have any digital to analog converters, so some advanced timing trickery will have to save the day.

The ESP32-C3 is a single-core Wi-Fi and Bluetooth 5 (BLE) microcontroller SoC, based on the open-source RISC-V architecture. It strikes a nice balance of power, I/O capabilities, and security, thus offering the optimal cost-effective solution for connected devices.

Before doing any soldering...

Let's power up the ESP32-C3 Supermini Development Board and verify the tool chain.

When power is first applied to the board using a USB-C cable, the Red Power LED (PWR in the image) will illuminate and the Blue Onboard LED (IO8 in the image) may blink.

Install the Arduino IDE, if necessary.

Within the IDE, use the Boards Manager to search for ESP32 (by Espressif Systems).

Select that board package and hit install.

Select: Tools > Board > ESP32 > Nologo ESP32C3 Super Mini

Open the example sketch:

File > Examples > Basics > Blink

Program the sketch to the board.

If the programming process has a connection error, force the development board into bootloader mode:

1. Hold down the BOOT button
2. Press the reset (RST) button
3. Release the RST button
4. Release the BOOT button
5. Try to program the sketch again

If everything is in order, the blue onboard LED (GPIO 8) will blink. If it was already blinking prior to this, experiment with changing the values in the delay() calls to alter the timing of the blink pattern.

After programming, you may need to reset the development board (press the RST button) to force a restart.

Some interesting thoughts on the CA-C03 ceramic chip antenna used on this development board.

NOW, CAREFULLY SOLDER THE PINS ONTO THE MCU BOARD

AND IT IS FINALLY RADIO FREQUENCY TRANSMITTER TIME...

To implement an AM transmitter on the ESP32-C3, we can leverage hardware timing by using the LEDC (LED Control) peripheral. We need to configure a high-frequency PWM carrier and rapidly update its duty cycle to match an audio signal. The ESP32_C3_AM_Transmit.ino sketch attached below sets up a 1,000 kHz (1 MHz) carrier wave on GPIO 4. Then, the sketch modulates the carrier using a pre-computed 1 kHz sine wave array to approximate a 1 KHz audio tone.

Connect the 10cm female-female DuPont jumper to the the pin corresponding to GPIO 4. Because the sketch generates a square wave directly to a digital pin, it produces strong harmonics. Keeping the wire short ensures it only propagates for a few inches, remaining safe and compliant with local radio frequency regulations.

Set the switches on the quad-band receiver to AM and MW. Turn the tuning knob to point around 1000. Remove the SMA antenna and position the GPIO 4 jumper wire very close the SMA antenna connector of the receiver. Make small moves on the tuning knob until you hear the 1 kHz audio buzz from the ESP32-C3 "transmitter" on 1 MHz. Momentarily hold down the RESET button on the ESP32 to note that the audio buzz ceases but then returns when you release the button.

If 1000 kHz (1 MHz) is crowded by a powerful local station in your area, change #define AM_CARRIER_FREQ to another blank frequency, such as 800000 (800 kHz) or 1200000 (1200 kHz) and try again. You should be able to pick up the 1 kHz audio hum on the quad-band receiver turned to the appropriate frequency.

Reference: Sections 6.4.2 and 6.4.3 from the book ESP32-C3 Wireless Adventure: A Comprehensive Guide to IoT cover operation of theESP32 LED PWM Controller (LEDC).

Watch this video! If possible, watch it again. Peruse the three links in the next paragraph. Build and operate a few pieces of radio equipment. Revisit every 3-24 months until it almost makes you crazy. Step back from the edge and close your eyes to the octopus ride. On that day, possibly decades from now, you will be a true RF wizard - Master of Black Magic.

The Smith Chart (Wikipedia) is a circular plot used in radio frequency (RF) engineering to solve transmission line and impedance-matching problems. It plots a complex reflection coefficient on a grid of normalized electrical impedance. Although paper charts have mostly been replaced by software for calculations, the display format remains standard across RF simulation software and vector network analyzers to visualize how parameters change with frequency.

Recap some of the fun we got up to in Las Vegas at DEF CON 34 including a few teasers likely to appear in upcoming HackerBoxes. Also, get some additional details on your open invitation to COME SAIL WITH US on a glorious cruise ship to Cozumel, Mexico in February 2027.

The graphic above outlines 18 interesting AI courses that are currently available for free.

Similarly, here five free cybersecurity courses from premier universities and major tech platforms:

1. CS50's Introduction to Cybersecurity from Harvard University - Learn to protect devices and understand risks at home or work.
2. Cisco Networking Academy - Self-paced introductory courses on threat defense and foundational cybersecurity.
3. Google Cybersecurity Certificate path via Coursera (audit for free) to learn Linux, SQL, and security tasks.
4. CISA Learning Portal - Free, on-demand online training ranging from beginner to advanced skill levels.
5. SANS CyberAces from SANS Institute for free virtual workshops and foundational tutorials on operating systems, networks, and system administration.

Beyond AI and Cybersecurity, there are many other free online educational resources:

1. OpenCulture - Free cultural & educational media online
2. Class Central - Search for the best courses, wherever they exist
3. digitaldefynd - Curated lists of the best online courses
4. Odin Project - Free full stack web development curriculum
5. Alison - 6,000+ Free online courses with certificates & diplomas

We hope you are enjoying this month's HackerBox adventures into electronics, computer technology, and hacker culture. We aim to curate a challenging and rewarding experience of learning through experimentation and exploration. Thank you for joining us on this journey.

Reach out and share your success in the comments below. Email support@hackerboxes.com anytime with questions or whenever you need some help.

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