Chapter 3Electricity, Components and

Circuits

Fundamentals of Electricity• When dealing with electricity, what we are

referring to is the flow of electrons through a conductor.• Electrons are negatively charged atomic

particles.• A conductor is a material that allows electrons

to move with relative freedom within the material.

• An insulator is a material that does not allow electrons to move freely within the material.

Fundamentals of Electricity• In electronics and radio, we control the flow

of electrons to make things happen.• You need to have a basic understanding of

how and why we control the flow of electrons so that you can better operate your radio.

Basic Characteristics of Electricity

• There are three characteristics of electricity:• Voltage• Current• Resistance

Basic Characteristics of Electricity• Voltage

• Electromotive force (EMF) causing electrons to flow• a.k.a. – Electric potential

• Positive voltage attracts electrons• Negative voltage repels electrons• Measured in Volts (V)

Basic Characteristics of Electricity

• Current• a.k.a. – Amperage• Rate (quantity, not speed) at which electrons flow• Measured in Amperes (A)

• Often shortened to “Amps”• 1 Amp = 6.25 x 1018 electrons per second

• 6,250,000,000,000,000,000

Basic Characteristics of Electricity

• Resistance• Opposition to flow of electrons• Measured in Ohms (Ω)

Basic Characteristics of Electricity• The flow of water through a hose is a good

analogy to understand the three characteristics of electricity and how they are related.

Characteristics of Electricity are Inter-related

• Just like water flowing through a hose, changes in voltage, current and resistance affect each other.

• That effect is mathematically expressed in Ohm’s Law.

Ohm’s Law

• First published in 1827 by Georg Ohm in his book “Die galvanische Kette, mathematisch bearbeitet ”• Mathematically describes the relationship

between voltage, current, and resistance.• Most basic formula in electricity and

electronics.

Ohm’s Law• E = Electromotive Force

• Force causing electrons to flow

• I = Current Intensity• Number of electrons

flowing past a point in a given period of time

• R = Resistance• Opposition to flow of

electrons

E = I x RI = E/RR = E/I

T5A01 -- Electrical current is measured in which of the following units?

A. VoltsB. WattsC. OhmsD. Amperes

T5A03 -- What is the name for the flow of electrons in an electric circuit?

A. VoltageB. ResistanceC. CapacitanceD. Current

T5A05 -- What is the electrical term for the electromotive force (EMF) that causes electron flow?

A. VoltageB. Ampere-hoursC. CapacitanceD. Inductance

T5A07 -- Which of the following is a good electrical conductor?

A. GlassB. WoodC. CopperD. Rubber

T5A08 -- Which of the following is a good electrical insulator?

A. CopperB. GlassC. AluminumD. Mercury

T5A11 -- What is the basic unit of electromotive force?

A. The voltB. The wattC. The ampereD. The ohm

T5D01 -- What formula is used to calculate current in a circuit?

A. Current (I) equals voltage (E) multiplied by resistance (R)B. Current (I) equals voltage (E) divided by resistance (R)C. Current (I) equals voltage (E) added to resistance (R)D. Current (I) equals voltage (E) minus resistance (R)

T5D02 -- What formula is used to calculate voltage in a circuit?

A. Voltage (E) equals current (I) multiplied by resistance (R)

B. Voltage (E) equals current (I) divided by resistance (R)

C. Voltage (E) equals current (I) added to resistance (R)

D. Voltage (E) equals current (I) minus resistance (R)

T5D03 -- What formula is used to calculate resistance in a circuit?

A. Resistance (R) equals voltage (E) multiplied by current (I) B. Resistance (R) equals voltage (E) divided by current (I)C. Resistance (R) equals voltage (E) added to current (I)D. Resistance (R) equals voltage (E) minus current (I)

The Electric Circuit:An Electronic Roadmap

• For current to flow, there must be a path from one side of the source of the current to the other side of the source – this path is called a circuit.• There must be a hose (conductive path) through

which the water (current) can flow.

Types of Circuits• Series Circuit.

• Provides one and only one path for current flow.

Types of Circuits• Parallel Circuit

• Provides alternative paths for current flow.

Types of Circuits• Short Circuit

• Direct connection between 2 points in a circuit• Often unintentional

• Open Circuit• No path from one side of the source of the

current to the other side of the source• Often unintentional

Measuring Electricity• Voltage is measured with a voltmeter.

• Connected in parallel with circuit.• Current is measured with an ammeter.

• Connected in series with circuit.

Measuring Electricity

• Resistance is measured with an ohmmeter.• Measurement is accomplished by applying a

known voltage, measuring the current, & using Ohm’s Law to calculate the resistance.

• Power MUST be removed from circuit before measuring!

• Component should be removed from circuit, if possible.

The Multimeter• The most common test instrument is the

Volt-Ohm-Milliammmeter (VOM) or Multimeter.• Measures voltage, current, or resistance.• May have other functions.

The Multimeter Digital multimeter (DVM)

Very inexpensive. Often has extra features in

addition to measuring volts, amps, & ohms.

The Multimeter

The Multimeter If resistance reading is initially very low but

slowly increases to a higher value, it indicates the presence of a large capacitance in the circuit.

NEVER attempt to measure resistance with power applied to the circuit. You WILL damage your multimeter.

NEVER attempt to measure voltage with the resistance setting. You WILL damage your multimeter.

T7D01 -- Which instrument would you use to measure electric potential or electromotive force?

A. An ammeterB. A voltmeterC. A wavemeterD. An ohmmeter

T7D02 -- What is the correct way to connect a voltmeter to a circuit?

A. In series with the circuitB. In parallel with the circuitC. In quadrature with the circuitD. In phase with the circuit

T7D03 -- How is an ammeter usually connected to a circuit?

A. In series with the circuitB. In parallel with the circuitC. In quadrature with the circuitD. In phase with the circuit

T7D04 -- Which instrument is used to measure electric current?

A. An ohmmeterB. A wavemeterC. A voltmeterD. An ammeter

T7D05 -- What instrument is used to measure resistance?

A. An oscilloscopeB. A spectrum analyzerC. A noise bridgeD. An ohmmeter

T7D06 -- Which of the following might damage a multimeter?

A. Measuring a voltage too small for the chosen scaleB. Leaving the meter in the milliamps position overnightC. Attempting to measure voltage when using the resistance settingD. Not allowing it to warm up properly

T7D07 -- Which of the following measurements are commonly made using a multimeter?

A. SWR and RF powerB. Signal strength and noiseC. Impedance and reactanceD. Voltage and resistance

T7D10 -- What is probably happening when an ohmmeter, connected across an unpowered circuit, initially indicates a low resistance and then shows increasing resistance with time?

A. The ohmmeter is defectiveB. The circuit contains a large capacitorC. The circuit contains a large inductorD. The circuit is a relaxation oscillator

T7D11 -- Which of the following precautions should be taken when measuring circuit resistance with an ohmmeter?

A. Ensure that the applied voltages are correctB. Ensure that the circuit is not poweredC. Ensure that the circuit is groundedD. Ensure that the circuit is operating at the

correct frequency

T7D12 -- Which of the following precautions should be taken when measuring high voltages with a voltmeter?

A. Ensure that the voltmeter has very low impedanceB. Ensure that the voltmeter and leads are rated for use at the voltages to be measuredC. Ensure that the circuit is grounded through the voltmeterD. Ensure that the voltmeter is set to the correct frequency

Moving Electrons Doing Something Useful

• Any time energy is expended to do something, work is performed.

• When moving electrons do some work, power is consumed.• Unit of measurement of power is the Watt

(W).

Power

• Power is defined as the rate at which energy is used to do work.• It takes 10x more power to expend a given

amount of energy in 1 minute than it does to expend the same amount of energy in 10 minutes.

Power Formula

I = P / E

P

E IWatts

Volts Amps

E = P / IP = E x I

• P = Power• Rate at which energy

is expended.• E = Voltage• I = Current

Two Basic Kinds of Current• When current flows in only one direction, it

is called direct current (DC).• Batteries are a common source of DC.• Most electronic devices are powered by DC.

• When current flows alternatively in one direction then in the opposite direction, it is called alternating current (AC).• Rate at which direction changes is called the

frequency.• Your household current is AC.

T5A02 -- Electrical power is measured in which of the following units?

A. VoltsB. WattsC. OhmsD. Amperes

T5A04 -- What is the name for a current that flows only in one direction?

A. Alternating currentB. Direct currentC. Normal currentD. Smooth current

T5A09 -- What is the name for a current that reverses direction on a regular basis?

A. Alternating currentB. Direct currentC. Circular currentD. Vertical current

T5A10 -- Which term describes the rate at which electrical energy is used?

A. ResistanceB. CurrentC. PowerD. Voltage

T5C08 -- What is the formula used to calculate electrical power in a DC circuit?

A. Power (P) equals voltage (E) multiplied by current (I)B. Power (P) equals voltage (E) divided by current (I)C. Power (P) equals voltage (E) minus current (I)D. Power (P) equals voltage (E) plus current (I)

T5C09 -- How much power is being used in a circuit when the applied voltage is 13.8 volts DC and the current is 10 amperes?

A. 138 wattsB. 0.7 wattsC. 23.8 wattsD. 3.8 watts

T5C10 -- How much power is being used in a circuit when the applied voltage is 12 volts DC and the current is 2.5 amperes?

A. 4.8 wattsB. 30 wattsC. 14.5 wattsD. 0.208 watts

T5C11 -- How many amperes are flowing in a circuit when the applied voltage is 12 volts DC and the load is 120 watts?

A. 0.1 amperesB. 10 amperesC. 12 amperesD. 132 amperes

T5A12 -- What term describes the number of times per second that an alternating current reverses direction?

A. Pulse rateB. SpeedC. WavelengthD. Frequency

Basic Electronic Components There are 3 basic types of components:

Resistor Unit of measurement of resistance is the ohm (Ω).

Capacitor Unit of measurement of capacitance is the farad

(F). Inductor

Unit of measurement of inductance is the henry (H).

The Resistor• The function of the resistor is to reduce

(limit) the flow of current through it.• Potentiometer.• Volume Control

The Resistor

• A fixed amount of partially conductive material.• Ratings

• Resistance• Ohms (Ω), kilohms (kΩ), megohms (MΩ)• Values from <1 Ω to >10 MΩ.

• Maximum power in watts (W).• Values from a fraction of a watt to a couple to >100

W.

Capacitance

• Capacitance is the ability to store energy in an electric field.• The unit of measurement of capacitance is the

Farad (F).• 1F is a very large value.• Capacitors are commonly available in values ranging

from 1pF to a few hundred thousand microfarads.

The Capacitor• The function of the capacitor is to

temporarily store electrical energy in an electric field.• Like a very temporary storage battery.

• Two conductive surfaces separated by an insulator.

• Ratings• Capacitance in picofarads (pF), microfarads

(μF), or farads (F)• Values from 1 pF to 1 F.

• Maximum voltage in volts (V), or kilovolts (kV)• Values from a few volts to several kilovolts.

The Capacitor

Inductance

• Inductance is the ability to store energy in a magnetic field.• The unit of measurement of inductance is the

Henry (H).• Inductors are commonly available in values ranging

from 1µH to a few Henries.

The Inductor

• The function of the inductor is to temporarily store electrical energy in a magnetic field.• Basically a coil of wire.

The Transformer

• One function of the transformer is to change AC voltage levels.

Components

• Color Code.• Component values often marked on

component by colored stripes or dots.• Very common with resistors• Less common with capacitors and inductors.

• Axial-lead cases.

Components

Components

• Color Code. • Bad Beer Rots Out Your Guts But

Veggies Go Well.• Get Some Now (tolerance)

T5C01 -- What is the ability to store energy in an electric field called?

A. InductanceB. ResistanceC. ToleranceD. Capacitance

T5C02 -- What is the basic unit of capacitance?

A. The faradB. The ohmC. The voltD. The henry

T5C03 -- What is the ability to store energy in a magnetic field called?

A. AdmittanceB. CapacitanceC. ResistanceD. Inductance

T5C04 -- What is the basic unit of inductance?

A. The coulombB. The faradC. The henryD. The ohm

T6A01 -- What electrical component is used to oppose the flow of current in a DC circuit?

A. InductorB. ResistorC. VoltmeterD. Transformer

T6A02 -- What type of component is often used as an adjustable volume control?

A. Fixed resistorB. Power resistorC. PotentiometerD. Transformer

T6A03 -- What electrical parameter is controlled by a potentiometer?

A. InductanceB. ResistanceC. CapacitanceD. Field strength

T6A04 -- What electrical component stores energy in an electric field?

A. ResistorB. CapacitorC. InductorD. Diode

T6A05 -- What type of electrical component consists of two or more conductive surfaces separated by an insulator?

A. ResistorB. PotentiometerC. OscillatorD. Capacitor

T6A06 -- What type of electrical component stores energy in a magnetic field?

A. ResistorB. CapacitorC. InductorD. Diode

T6A07 -- What electrical component is usually composed of a coil of wire?

A. SwitchB. CapacitorC. DiodeD. Inductor

T6D06 -- What component is commonly used to change 120V AC house current to a lower AC voltage for other uses?

A. Variable capacitorB. TransformerC. TransistorD. Diode

Reactance & Impedance• In circuits containing only resistors, voltage

& current are always “in phase”.• Current flow changes at the same time and in

the same direction as the voltage change.

• Special kind of resistance to the flow of AC called reactance (X).• Reactance also measured in Ohms (Ω).

Reactance & Impedance• In circuits containing capacitors or

inductors, voltage & current are “out of phase”.• Current flow changes before the voltage

changes in a capacitor.• Current “leads” voltage.

• Current flow changes after the voltage changes in an inductor.• Current “lags” voltage.ELI the ICEman

Reactance & Impedance

• Opposition to AC current flow in capacitors or inductors is called reactance (X, XC, or XL).• Reactance is also measured in Ohms (Ω).

Reactance & Impedance

• Combination of resistance and reactance is called impedance (Z).• Impedance also measured in Ohms (Ω).

Resonance

• Because current leads voltage in a capacitor & lags voltage in an inductor, a combination exists where the lead time & lag time cancel, resulting in the current & voltage being in phase.

Resonance

• This condition is called resonance.• Resonant circuit.• Tuned circuit.• Impedance of a resonant circuit is purely

resistive.• Reactance = 0Ω

T5C12 -- What is meant by the term impedance?

A. It is a measure of the opposition to AC current flow in a circuitB. It is the inverse of resistanceC. It is a measure of the Q or Quality Factor of a componentD. It is a measure of the power handling capability of a component

T5C13 -- What are the units of impedance?

A. VoltsB. AmperesC. CoulombsD. Ohms

T6D08 -- Which of the following is used together with an inductor to make a tuned circuit?

A. ResistorB. Zener diodeC. PotentiometerD. Capacitor

T6D11 -- What is a simple resonant or tuned circuit?

A. An inductor and a capacitor connected in series or parallel to form a filterB. A type of voltage regulatorC. A resistor circuit used for reducing standing wave ratioD. A circuit designed to provide high fidelity audio

Break

Protective Components – Intentional Open Circuits

• Fuses and circuit breakers are designed to interrupt the flow of current if the current becomes to large• Fuses blow – one time protection• Circuit breakers trip – can be reset and

reused

The Switch• The function of the switch is to turn on or off

or to redirect the flow of current.

The Relay• A relay is an electrically-controlled switch.

• A set of switch contacts connected to an electromagnet.

The Meter• A meter displays an electrical value on a

numeric scale.• All analog meters are ammeters.

• A voltmeter is an ammeter with a series resistor.

T6A09 -- What electrical component is used to protect other circuit components from current overloads?

A. FuseB. CapacitorC. InductorD. All of these choices are correct

T0A04 -- What is the purpose of a fuse in an electrical circuit?

A. To prevent power supply ripple from damaging a circuit

B. To interrupt power in case of overloadC. To limit current to prevent shocksD. All of these choices are correct

T0A05 -- Why is it unwise to install a 20-ampere fuse in the place of a 5-ampere fuse?

A. The larger fuse would be likely to blow because it is rated for higher currentB. The power supply ripple would greatly increaseC. Excessive current could cause a fireD. All of these choices are correct

T6A08 -- What electrical component is used to connect or disconnect electrical circuits?

A. MagnetronB. SwitchC. ThermistorD. All of these choices are correct

T6D02 -- Which best describes a relay?

A. A switch controlled by an electromagnetB. A current controlled amplifierC. An optical sensorD. A pass transistor

T6D04 -- Which of the following can be used to display signal strength on a numeric scale?

A. PotentiometerB. TransistorC. MeterD. Relay

The Diode• The function of the diode is to allow the

flow of current in only one direction.• An analogy, a check valve in a water system.

The Diode• One use of a diode is as a rectifier in a

power supply circuit to convert an AC voltage into a varying DC voltage.

The Diode• Light-Emitting Diode (LED).

• Emits light when forward-biased.

The Transistor• The function of the transistor is to variably

control the flow of current.• Much like an electronically controlled valve.• An analogy, the faucet in your sink.

NPN PNP

The Transistor• Bipolar Transistors.• Small change in base current results in large

change in emitter current.• Low input & output impedances.

The Transistor• Field-Effect Transistors (FET).• Small change in gate voltage results in large

change in drain current.• High input impedance & low output impedance.

The Integrated Circuit• The integrated circuit is a collection of

components contained in one device that accomplishes a specific task.• Acts like a “black-box”

T6B01 -- What class of electronic components is capable of using a voltage or current signal to control current flow?

A. CapacitorsB. InductorsC. ResistorsD. Transistors

T6B02 -- What electronic component allows current to flow in only one direction?

A. ResistorB. FuseC. DiodeD. Driven element

T6B03 -- Which of these components can be used as an electronic switch or amplifier?

A. OscillatorB. PotentiometerC. TransistorD. Voltmeter

T6B04 -- Which of the following components can be made of three layers of semiconductor material?

A. AlternatorB. TransistorC. TriodeD. Pentagrid converter

T6B05 -- Which of the following electronic components can amplify signals?

A. TransistorB. Variable resistorC. Electrolytic capacitorD. Multi-cell battery

T6B06 -- How is the cathode lead of a semiconductor diode usually identified?

A. With the word cathodeB. With a stripeC. With the letter CD. All of these choices are correct

T6B07 -- What does the abbreviation LED stand for?

A. Low Emission DiodeB. Light Emitting DiodeC. Liquid Emission DetectorD. Long Echo Delay

T6B08 -- What does the abbreviation FET stand for?

A. Field Effect TransistorB. Fast Electron TransistorC. Free Electron TransitionD. Field Emission Thickness

T6B09 -- What are the names of the two electrodes of a diode?

A. Plus and minusB. Source and drainC. Anode and cathodeD. Gate and base

T6B10 -- What are the three electrodes of a PNP or NPN transistor?

A. Emitter, base, and collectorB. Source, gate, and drainC. Cathode, grid, and plateD. Cathode, drift cavity, and collector

T6B11 -- What at are the three electrodes of a field effect transistor?

A. Emitter, base, and collectorB. Source, gate, and drainC. Cathode, grid, and plateD. Cathode, gate, and anode

T6B12 -- What is the term that describes a transistor’s ability to amplify a signal?

A. GainB. Forward resistanceC. Forward voltage dropD. On resistance

T6D01 -- Which of the following devices or circuits changes an alternating current into a varying direct current signal?

A. TransformerB. RectifierC. AmplifierD. Reflector

T6D07 -- Which of the following is commonly used as a visual indicator?

A. LEDB. FETC. Zener diodeD. Bipolar transistor

T6D09 -- What is the name of a device that combines several semiconductors and other components into one package?

A. TransducerB. Multi-pole relayC. Integrated circuitD. Transformer

Other Circuit Symbols

Putting It All Together in a Circuit Diagram

T6D10 -- What is the function of component 2 in Figure T1?

A. Give off light when current flows through itB. Supply electrical energyC. Control the flow of currentD. Convert electrical energy into radio waves

T6C01 -- What is the name for standardized representations of components in an electrical wiring diagram?

A. Electrical depictionsB. Grey sketchC. Schematic symbolsD. Component callouts

T6C13 -- Which of the following is accurately represented in electrical circuit schematic diagrams?

A. Wire lengthsB. Physical appearance of componentsC. The way components are interconnectedD. All of these choices are correct

The Basic Radio Station

Circuits Used in Radios

• Transmit/Receive (TR) Switch • If the station antenna is shared between the

transmitter and receiver, the TR switch allows the antenna to be switched to the transmitter when sending and to the receiver when receiving.• In a transceiver, the TR switch is inside the unit and

requires no attention from the operator.

Circuits Used in Radios

• Oscillators• An oscillator produces a steady AC voltage on a

single frequency.• Used in both receivers & transmitters to determine

operating frequency.• Variable-frequency oscillator (VFO).

Circuits Used in Radios • Amplifiers

• An amplifier increases the strength of a signal.• Increase voltage, current, or power.• Amount of increase is called “gain”.

• Numeric value – For example, a gain of 10 means the output signal is 10 times bigger than input signal.

• dB – For example, a power gain of 3 dB means the output signal has twice the power than the input signal.

Simple CW Transmitter Block Diagram

Circuits Used in Radios

• Filters• Filters reject (attenuate) unwanted signals.

• Passive filters.• Capacitors, inductors, & resistors.• Tuned circuits are common examples of passive filters.

• Active filters• Amplifiers with circuits to reject unwanted signals.• Can have gain.

Circuits Used in Radios • Filter classifications.

• Low pass.• High pass.• Band pass.• Band reject (notch).

Circuits Used in Radios

• Mixers.• Mixes 2 different frequency signals together to

produce 4 output frequencies.• f1 x f2 f1, f2, f1-f2, & f1+f2.• Usually only one output frequency wanted, so filters

remove other 3 frequencies.• Used in both transmitters & receivers.

Circuits Used in Radios

• Modulators• Encode information (voice, data, etc.) onto an RF

signal (carrier)• Can be as simple as on-off switch

• Telegraph key• Can be very complex

Circuits Used in Radios

• Demodulators• Extracts information (voice, data, etc.) from RF

signal (carrier)• Several different types of demodulators used in

amateur radio equipment depending on type of modulation being used

Circuits Used in Radios

• Simple detectors• Envelope detector used to demodulate AM

signals

• Product detectors• One application of a mixer circuit• Used to demodulate CW & SSB signals

• Frequency discriminators• Used to demodulate FM signals

Receivers • Types:

• Direct Conversion.• Local oscillator at (or near) frequency of signal to be

received. • Advantage: Very easy to filter at audio frequency.• Advantage: No image responses.• Disadvantage: High stability local oscillator required.• Most software-defined radios (including cell phones)

use direct-conversion.

Receivers • Types:

• Heterodyne.• RF & local oscillator fed into mixer to move signal to a

lower intermediate frequency (IF) for filtering & demodulation.

• Advantage: Easier to filter at lower frequency.• Disadvantage: Image responses.• Superheterodyne.

Superheterodyne Receiver Block Diagram

Superheterodyne Receiver • Single-conversion.

• One mixer.• One IF frequency.

• Double-conversion.• Two mixers.• Two IF frequencies.• 2nd IF frequency very low for easier filtering.

• 2nd IF typically 455 kHz.• Not used much any more.

FM Receiver Block Diagram

FilterMixer

Osc

Limiter

Frequency Discriminator Spkr

Receivers • Two primary characteristics:

• Sensitivity.• Ability to receive weak signals.• Sometimes a pre-amplifier (pre-amp) is added

between antenna & receiver to improve sensitivity.• Selectivity.

• Ability to reject unwanted signals.

Transverter • Converts a band of frequencies to a different

band of frequencies.• Both transmit and receive.• Usually used for VHF/UHF/SHF/EHF operation.• Driven by a low-power signal from an HF

transceiver (typically 28 MHz).• Amateur Satellites.

T7A01 – Which term describes the ability of a receiver to detect the presence of a signal?

A. LinearityB. SensitivityC. SelectivityD. Total Harmonic Distortion

T7A03 -- Which of the following is used to convert a radio signal from one frequency to another?

A. Phase splitterB. MixerC. InverterD. Amplifier

T7A04 – Which terms describes the ability of a receiver to discriminate between multiple signals?

A. Discrimination ratioB. SensitivityC. SelectivityD. Harmonic Distortion

T7A05 -- What is the name of a circuit that generates a signal of a desired frequency?

A. Reactance modulatorB. Product detectorC. Low-pass filterD. Oscillator

T7A08 -- Which of the following describes combining speech with an RF carrier signal?

A. Impedance matchingB. OscillationC. ModulationD. Low-pass filtering

T7A06 -- What device takes the output of a low-powered 28 MHz SSB exciter and produces a 222 MHz output signal?

A. High-pass filterB. Low-pass filterC. TransverterD. Phase converter

T7A11 -- Where is an RF preamplifier installed?

A. Between the antenna and receiverB. At the output of the transmitter’s power

amplifierC. Between a transmitter and antenna tunerD. At the receiver’s audio output

Questions?