Because the question pool committee combined sections G6A and G6B from the 2011 question pool into a single section, the 2011 section G6C becomes G6B in this year’s pool. Aside from that, only two questions changed, and they were very minor changes. Question G6B07 now asks what is one advantage of an LED over an incandescent indicator instead of asking what is the disadvantage of an incandescent indicator when compared to an LED.
Question G6B12 is unchanged, but the answer was corrected. In the 2011 pool, the correct answer was “DB-9,” but the technically correct answer is “DE-9.” According to NullModem.Com, “The DE-9 D-sub 9-pin connector is often mistakenly referred to as the “DB-9” connector. The “E” refers to the shell size. A “DB-25” connector has a “B” size shell, but the common nine-pin connector is smaller and has an “E” size shell. ” You learn something new every day.
Analog and digital integrated circuits (IC’s); microprocessors; memory; I/O devices; microwave IC’s (MMIC’s ); display devices
Most amateur radio devices today contain integrated circuits (ICs). On a single piece of silicon, manufacturers can put thousands of transistors, implementing very complex circuit functions.
ICs may contain analog circuits, digital circuits, or a combination of both. A simple example is the linear voltage regulator, which is an analog integrated circuit (G6B01). Analog is also the term that describes an integrated circuit operational amplifier. (G6B06)
A more sophisticated analog IC is the MMIC. The term MMIC means Monolithlic Microwave Integrated Circuit. (G6B02)
Digital ICs are often described by the technology used to create the transistors. One type, or “family,” of digital IC uses complementary, metal-oxide semiconductor, or CMOS, transistors. CMOS has several advantages over other IC technologies, such as transistor-transistor logic (TTL). Low power consumption is an advantage of CMOS integrated circuits compared to TTL integrated circuits. (G6B03)
Memories are an important type of digital IC. One type of memory is the read-only memory, or ROM, which is often used to store programs or data that never changes. The term ROM means Read Only Memory. (G6B04) ROM is characterized as “non-volatile,” meaning the stored information is maintained even if power is removed. (G6B05)
ROMs are often used to store programs that run microprocessors. A microprocessor is a computer on a single integrated circuit. (G6B11) Modern amateur radio transceivers usually have one or more microprocessors to control their operation.
Modern transceivers use light-emitting diodes (LEDs) or liquid crystal displays (LCDs) to display operating status, such as frequency. An LED is forward biased when emitting light. (G6B08) Older radios often used incandescent bulbs instead of LEDs. Lower power consumption is one advantage of an LED when compared to an incandescent indicator. (G6B07)
LCDs do not emit light. Therefore, one of the characteristics of a liquid crystal display is that it requires ambient or back lighting. (G6B09)
Most modern transceivers can now be controlled by a computer. A common way to connect a computer to a transceiver is with a USB interface. A computer and transceiver are two devices in an amateur radio station that might be connected using a USB interface. (G6B10)
To connect all of the devices we typically have in an amateur radio station, we use many different types of connecters. For example, a DE-9 connector would be a good choice for a serial data port. (G6B12) An RCA Phono connector is commonly used for audio signals in Amateur Radio stations. (G6B14)
Many connectors were designed specifically to connect RF signals. A PL-259 connector is commonly used for RF service at frequencies up to 150 MHz. (G6B13) The type-N connector is a moisture-resistant RF connector useful to 10 GHz. (G6B16) The SMA connector is a small threaded connector suitable for signals up to several GHz. (G6B18)
To help users make sure they make the right connections, some connectors are keyed. The main reason to use keyed connectors instead of non-keyed types is reduced chance of incorrect mating. (G6B15) DIN connectors are one type of keyed connector. The general description of a DIN type connector is a family of multiple circuit connectors suitable for audio and control signals. (G6B17)