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Serious ‘XM (That’s W2XM) presents. Exam-prep Jepperdee : Extra-class Edition. Announcements Introduction of presenter. - PowerPoint PPT Presentation
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Serious ‘XM(That’s W2XM)
presents
Exam-prep Jepperdee:
Extra-class Edition
Announcements
Introduction of presenter
Operation of the game is almost intuitive, and you can make up your own rules. Each numeric point value on either game board is a hyperlink which reveals a question. Advancing the game one slide past the question (by clicking the screen) displays the answer. “Back” on the answer slide returns you to the game board. “SFJ” stands for “semi-final jepperdee” and “FJ” means “final jepperdee;” proceed from SFJ or FJ by clicking screen until you see the next hyperlink. There is one daily double on each board; click on “Here’s the question.”
For most fun, appropriate hardware (lights, push-buttons, sounder, lockout circuitry) should be used. A diagram is available from the author.
OPERATING PRACTICES
RULES AND REGULATIONS
ELECTRICAL PRINCIPALS
COMPONENTS & BLDG BLOCKS
100 100 100 100
200 200 200 200
300 300 300 300
400 400 400 400
500 500 500 500 SFJ
Electronic Circuits
Radio Sigs. & Msrmnts
Modes & Equipment
Antennas/ Propagation
100 100 100 100
200 200 200 200
300 300 300 300
400 400 400 400
500 500 500 500 FJ
E2C06 During a VHF-UHF contest, in which band segment would you expect to find the
highest level of activity?
The weak-signal segment of the
band, with most of the activity near the
calling frequencyback
E2C07
What is the Cabrillo format?
A standard for submission of
electronic contest logs
back
E2D07 Which digital protocol is used by
APRS: PACTOR, 802.11, AX.25, or
AMTOR?
AX.25
back
E2A02 What is the direction of a
descending pass for an amateur
satellite?
From north to south
back
E2A09 What do the terms L band and S band specify with regard to satellite communications?
The 23-cm and 13-cm bands
back
E1A05 What is the maximum power output permitted on the 60 meter
band?
100 watts PEP effective radiated power relative to the gain of a half-
wave dipole back
E1C01 What is a remotely
controlled station?
A station controlled indirectly through a
control linkback
E1D08 Which VHF amateur-service
bands have frequencies available
for space stations?
2 meters
back
E1F14 When/why might the FCC issue "Special Temporary Authority" (STA) to
an amateur station?
To provide for experimental
amateur communications
back
E1B05 What is the maximum
bandwidth for a data emission on
60 meters?
2.8 kHz
back
E6D08 Why use powdered-iron
toroids rather than ferrite ones in an
inductor?
Powdered-iron toroids generally
maintain their characteristics at higher currents back
E5B04 What is the time constant of a circuit having two 220-μF caps and two 1-MΩ res., all in parallel?
220 seconds
back
E5A08 What is the phase between the I through and the v across a series resonant circuit?
The voltage and current are in
phaseback
E5C04 Expressed in polar, what is the z of
a 400-Ω reactance cap in series with a
300-Ω resistor?
500 ohms at an angle of -53.1
degreesback
E5D12 How many watts are consumed in a
circuit having a p.f. of 0.2 if the input is 100-V AC at 4 A?
80 watts
back
E6A08 What do we call the freq. at which the grounded-base cur-
rent gain of a transis-tor is .7 X the gain at
1 kHz?
alpha cutoff frequency
back
E6E06 What charac-teristics of the MMIC
make it a good choice for VHF-
through-microwave circuits?
Controlled gain, low noise figure, &
constant in and out Z’s over a given frequency rangeback
E6D13 What type of CRT deflection is best
when high-frequency waveforms are to be
displayed?
Electrostatic
back
E6B04 What type of semiconductor
device is used as a voltage-controlled
capacitor?
Varactor diode
back
E6D06 What property of the core material determines the inductance of a
toroidal inductor?
Permeability
back
E7B12
What is this?
Figure E7-1
Common emitter amplifier
back
E6E10 What is the equivalent circuit
of a quartz crystal?
Motional C, motional L, and loss R all in
series; with a shunt C representing elect-rode and stray C back
E7H13 Define “capture range”
of a phase-locked loop circuit?
The frequency range over which
the circuit can lockback
E7C07 What kind of filter would attenuate an interfering signal as you are receiving an SSB transmission?
A notch filter
back
E7D13 Purpose of D1?
Figure E7- 3
C1 C3
+25 +12
R2R1
C2 D14000
4000 0.01
Q1
To provide a voltage reference
back
E8D15 What is the typ-ical nominal value for the RMS voltage at a standard household a.c. power outlet?
120V
back
E8A06 What is the approximate ratio of PEP-to-average power in a typical SSB phone signal?
2.5 to 1
back
E4A03 Which would a spectrum analyzer
display on the vertical axis: Amplitude,
Duration, SWR, or Q?
Amplitude
back
E8B08 What parameter is varied by the
modulating signal in a pulse-position
modulation system?
The time at which each pulse occurs
back
E4E07 How can you determine if line-
noise interference is being generated
within your home?
By turning off the AC-power main
breaker and listen-ing on a battery operated radio back
E2D12 How does JT65 improve EME
communications?
It can decode signals many dB below the noise floor using FEC
back
E8C05 What is the necessary bandwidth
of a 13-WPM international Morse code transmission?
Approximately 52 Hz
back
E2B09 What hardware, besides a receiver & computer, is needed to decode SSTV using
Digital Radio Mondiale
(DRM)?
No other hardware is
needed
back
E4C04 What is the definition of the “noise figure” of
a receiver?
The ratio of the noise generated by the receiver to the theoretical mini-mum noise (in dB)
back
E6E05 What noise figure value might
be typical of a low-noise UHF
preamplifier?
2 dB
back
E9A09 What is meant by antenna bandwidth?
The frequency range over which
an antenna satisfies a performance requirement
back
E9D13 What happens to Z at the feed point of a fixed-length ant. as
the frequency of operation is lowered?
The radiation resis-tance decreases &
the capacitive reactance increases. back
E9F06 What is the approx. length of an air-insulated parallel conductor xmission
line that is λ/2 long at 14.1 MHz?
10 meters
back
E3B02 What is the approx. maximum range for signals
using transequatorial propagation?
5000 miles
back
E0A07 How may dan-gerous levels of car-bon monoxide from
an emergency gener-ator be detected?
Only with a carbon monoxide detector
back
Semi-final Jepperdee
topic:A.C. waveform
For a sinusoidal voltage, how do
the peak and rms values compare?
peak voltage = 1.414 X rms voltage
ORVrms = .707 X Vpeak
(to second game board)
Final Jepperdee
topic:hazardous materials
E0A09 Which insulating material used as a
thermal conductor is extremely toxic if
broken or crushed and accidentally inhaled?
Beryllium Oxide
Thanks for playingExam-prep Jepperdee:Extra-class
Edition