Amateur Radio Technician Class license test study notes

I wanted to share some of my study notes from the Technician Class Amateur Radio license test. There is a lot of information that might be of interest to the geeks out there.

Today I was granted my license from the FCC and my call sign is KG5DMX.

Source: The No-Nonsense Technician-Class License Study Guide (for tests after July 1, 2014)

Note: The complete pool of multiple choice test questions can be found at NCVEC.org. I also used an Android App called Ham Test Prep to practice answering questions.

Q. What types of international communications are permitted by an FCC-licensed amateur station?

  A. Communications incidental to the purposes of the amateur service and remarks of a personal character

Q. What name is given to an amateur radio station that is used to connect other amateur stations to the Internet?
  A. Gateway

Q. What is the Internet Radio Linking Project (IRLP)?

  A. A technique to connect amateur radio systems, such as repeaters, via the Internet using Voice Over Internet Protocol For more reliable long-distance communications, amateurs use the HF frequencies.

For more reliable long-distance communications, amateurs use the HF frequencies. UHF signals are often more effective from inside buildings than VHF signals because the shorter wavelength allows them to more easily penetrate the structure of buildings. (T3A02)

horizontal antenna polarization is normally used for long-distance weak-signal CW and SSB contacts using the VHF and UHF bands. (T3A03)

The primary advantage of single sideband over FM for voice transmissions is that SSB signals have narrower bandwidth. (T8A07)

The approximate bandwidth of a single sideband voice signal is 3 kHz. (T8A08)

The approximate bandwidth of a VHF repeater FM phone signal is between 10 and 15 kHz. (T8A09)

Morse Code, or CW, is the type of emission that has the narrowest bandwidth. (T8A05)

The approximate maximum bandwidth required to transmit a CW signal is 150 Hz. (T8A11)

International Morse is the code used when sending CW in the amateur bands. (T8D09)

All of these choices are correct when talking about instruments used to transmit CW in the amateur bands (T8D10):

Straight Key
  Electronic Keyer
Computer Keyboard

Some modes have very wide bandwidths. The typical bandwidth of analog fast-scan TV transmissions on the 70 cm band, for example, is about 6 MHz. (T8A10)

The type of transmission indicated by the term NTSC is an analog fast scan color TV signal. (T8D04)

Digital modes: packet, PSK31 When hams talk about “digital modes,” we are talking about modes that send digital data rather than voice or other types of analog signals, such as television. Usually, we connect our transceivers to a computer to modulate and demodulate the digital signals, but some newer transceivers can do this internally.

All of these choices are correct (examples of a digital communications method) (T8D01):

Packet
PSK31
MFSK

Packet radio was one of the first digital modes. It is called packet radio because the data to be sent from station to station is separated into a number of packets which are then sent separately by the transmitting station and received and re-assembled by the receiving station.

All of these choices are correct when talking about what may be included in a packet transmission (T8D08):

  A check sum which permits error detection
  A header which contains the call sign of the station to which the information is being sent Automatic repeat request in case of error

Some amateur radio digital communications systems use protocols which ensure error-free communications. One such system is called an automatic repeat request, or ARQ, transmission system. An ARQ transmission system is a digital scheme whereby the receiving station detects errors and sends a request to the sending station to retransmit the information. (T8D11)

APRS is one service that uses packet radio. The term APRS means Automatic Packet Reporting System. (T8D02)

A Global Positioning System receiver is normally used when sending automatic location reports via amateur radio. (T8D03)

Providing real time tactical digital communications in conjunction with a map showing the locations of stations is an application of APRS (Automatic Packet Reporting System). (T8D05)

A popular digital mode on the HF bands is PSK. The abbreviation PSK means Phase Shift Keying. (T8D06)
PSK31 is a low-rate data transmission mode. (T8D07)

The “31” in PSK31 comes from the fact that data is transmitted and received at about 31 baud and that the bandwidth of a PSK31 signal is only about 31 Hz.

Separate eight-foot long ground rods for each tower leg, bonded to the tower and each other is considered to be a proper grounding method for a tower. (T0B08)

When installing devices for lightning protection in a coaxial cable feedline, ground all of the protectors to a common plate which is in turn connected to an external ground. (T0A07)

The maximum power level that an amateur radio station may use at VHF frequencies before an RF exposure evaluation is required is 50 watts PEP at the antenna. (T0C03)

the human body absorbs more RF energy at some frequencies than at others. (T0C05)

The 50 MHz band has the lowest Maximum Permissible Exposure limit. (T0C02)

To reduce RF current flowing on the shield of an audio cable (or in a power supply cable), you would use a ferrite choke. (T4A09)

Flat strap is the type of conductor that is best to use for RF grounding. (T4A08)

One thing that would reduce ignition interference to a receiver is to turn on the noise blanker. (T4B05)

Another common setting on VHF/ UHF transceivers is the offset frequency. This is especially important when operating repeaters. The common meaning of the term “repeater offset” is the difference between the repeater’s transmit and receive frequencies. (T4B11)

Many, if not most, new amateurs buy a hand-held transceiver, usally called an “HT,” as their first transceiver. One disadvantage of using a hand-held transceiver is that the maximum output power is generally only 5 W, and because of this, they have limited range. To increase the low-power output of a handheld transceiver, and therefore its, range, you can use an RF power amplifier. (T7A10)

Operating Procedures FM Operation Once they get their licenses, most Technicians purchase a VHF/ UHF FM transceiver. This type of radio allows them to use repeaters and participate in public-service events. A repeater station is the type of amateur station that simultaneously retransmits the signal of another amateur station on a different channel or channels. (T1F09)

Auxiliary, repeater, or space stations amateur stations can automatically retransmit the signals of other amateur stations. (T1D07)

To use repeaters, you need to know how to set up your radio. Repeaters receive on one frequency and transmit on another. You program your radio so that it receives on the repeater’s transmit frequency and transmits on the repeater’s receive frequency. The difference between the transmit frequency and receive frequency is called the repeater frequency offset. Plus or minus 600 kHz is the most common repeater frequency offset in the 2 meter band. (T2A01)

Plus or minus 5 MHz is a common repeater frequency offset in the 70 cm band. (T2A03)

Repeater operation is called duplex operation because you’re transmitting and receiving on two different frequencies. When the stations can communicate directly without using a repeater, you should consider communicating via simplex rather than a repeater. (T2B12)

Simplex communication is the term used to describe an amateur station that is transmitting and receiving on the same frequency. (T2B01)

To help amateurs operating simplex find one another, frequencies on each band have been set aside as “national calling frequencies.” 446.000 MHz is the national calling frequency for FM simplex operations in the 70 cm band. (T2A02)

146.52 MHz is the national calling frequency for FM simplex operation in the 2 m band.

Because repeaters often operate in environments where there is a lot of interference they are programmed not to operate unless the station they are receiving is also transmitting a sub- audible tone of a specific frequency. These tones are sometimes called PL (short for “private line”) tones or CTCSS (short for “continuous tone-coded squelch system”) tones. CTCSS is the term used to describe the use of a sub-audible tone transmitted with normal voice audio to open the squelch of a receiver. (T2B02)

If your radio has not been programmed to transmit the proper sub-audible tone when you transmit, the repeater will not repeat your transmission.

All of these choices are correct when talking about common problems that might cause you to be able to hear but not access a repeater even when transmitting with the proper offset: (T2B04)
  • The repeater receiver requires audio tone burst for access
  • The repeater receiver requires a CTCSS tone for access
  • The repeater receiver may require a DCS tone sequence for access

One of the controls on a VHF/ UHF transceiver is the squelch control. Carrier squelch is the term that describes the muting of receiver audio controlled solely by the presence or absence of an RF signal. (T2B03)

Google Boosts Secure Sites in Search Results

This is great news! Google adjusted their ranking algorithms to favor (ever so slightly) sites that support HTTPS.

Source: Google via Electronic Frontier Foundation

"... we’d like to encourage all website owners to switch from HTTP to HTTPS to keep everyone safe on the web."

Rosetta arrives at comet destination

Source: ESA via Space Fellowship

NavCam animation 6 August. Copyright ESA/Rosetta/Navcam

“After ten years, five months and four days travelling towards our destination, looping around the Sun five times and clocking up 6.4 billion kilometres, we are delighted to announce finally ‘we are here’,” says Jean-Jacques Dordain, ESA’s Director General.

“Europe’s Rosetta is now the first spacecraft in history to rendezvous with a comet, a major highlight in exploring our origins. Discoveries can start.”
...
“Over the next few months, in addition to characterising the comet nucleus and setting the bar for the rest of the mission, we will begin final preparations for another space history first: landing on a comet,” says Matt.
...
“Arriving at the comet is really only just the beginning of an even bigger adventure, with greater challenges still to come as we learn how to operate in this unchartered environment, start to orbit and, eventually, land,” says Sylvain Lodiot, ESA’s Rosetta spacecraft operations manager.
...
“After landing, Rosetta will continue to accompany the comet until its closest approach to the Sun in August 2015 and beyond, watching its behaviour from close quarters to give us a unique insight and realtime experience of how a comet works as it hurtles around the Sun.”
...

A tiny technical change in iOS 8 could stop marketers spying on you

The original source of this article appears to be WWDC session 715, "User Privacy on iOS and OS X," presented by Apple Product Security and Privacy representatives David Stites and Katie Skinner.

Source: Quartz

Whenever you walk around a major Western city with your phone’s Wi-Fi turned on, you are broadcasting your location to government agencies, marketing companies and location analytics firms.
...
At the core of such tracking is the MAC address, a unique identification number tied to each device. Devices looking for a Wi-Fi network send out their MAC address to identify themselves. 
...
Apple’s solution, as discovered by a programmer, is for iOS 8, the new operating system for iPhones which will be out later this year, to generate a random MAC addresses while scanning for networks. 

We Are Now In Command of the ISEE-3 Spacecraft

Hooray for the nerds who made contact with a NASA probe that has survived well beyond its planned mission!
The International Sun-Earth Explorer (ISEE-3) is a spacecraft that was launched in 1978 to study Earth's magnetosphere and repurposed in 1983 to study two comets. Since 1983 the ICEE-3 probe has been traveling in a heliocentric orbit slightly faster than Earth and it will return close to Earth in August.  NASA has insufficient funding to communicate with ICEE-3 and therefore gave a private project team permission to communicate and control the probe.
Donations helped fund the project and the Arecibo Observatory in Puerto Rico was updated with a Software Defined Radio and a custom-made amplifier. Today the team was successful in communicating with the probe and they believe that they can order the probe to burn a thruster and move into orbit near earth until it can later be directed to observe a comet.

Source: Space College

By Keith Cowing on May 29, 2014 4:07 PM

The ISEE-3 Reboot Project is pleased to announce that our team has established two-way communication with the ISEE-3 spacecraft and has begun commanding it to perform specific functions. Over the coming days and weeks our team will make an assessment of the spacecraft's overall health and refine the techniques required to fire its engines and bring it back to an orbit near Earth.

First Contact with ISEE-3 was achieved at the Arecibo Radio Observatory in Puerto Rico. We would not have been able to achieve this effort without the gracious assistance provided by the entire staff at Arecibo. In addition to the staff at Arecibo, our team included simultaneous listening and analysis support by AMSAT-DL at the Bochum Observatory in Germany, the Space Science Center at Morehead State University in Kentucky, and the SETI Institute's Allen Telescope Array in California.

Of course this effort would not have been possible without the assistance of NASA and the Space Act Agreement crafted by NASA Headquarters, NASA Ames Research center, and the System Solar System Exploration Research Virtual Institute (SSERVI).

Why China is fixated on the Moon

Source: BBC News

I asked him if the idea of a Chinese moonbase extracting minerals was remotely plausible.

"It's perfectly plausible from the technical point of view, absolutely plausible from the finance point of view because they have great buying power, so I think, yes, there's nothing at all to stop them doing that probably within something like 10 years."

So a great deal is riding on the Chang'e 3 launch - national prestige, the quest for technological prowess and the desire to harness all available natural resources.

If all goes according to plan, the spacecraft will take six days to reach the Moon and then face the challenge of a soft landing.

How to Hack the Backbone of the Internet

Source: The Motherboard blog at Vice Magazine

The highlight of the NSA’s Powerpoint presentation is a hand-drawn slide of two circles that shows where the public internet meets Google's private cloud. That meeting point is a prime spot for the NSA to intercept traffic,  encryption is “added and removed here!” as the slide states, with a smiley face no less.