The average daily sunspot numbers this week were about the same as last week, while the average daily solar flux declined a little more than eight points to 128.9. Geomagnetic indicators were quiet. The average daily sunspot numbers of 95.3 for the week is considerably below the average for the previous 90 days, which was 120.8. Sunspot numbers for December 15-21 were 44, 60, 95, 103, 133, 139 and 93, with a mean of 95.3. The 10.7 cm flux was 124.2, 121, 119.6, 127.4, 128.2, 137.4 and 144.5, with a mean of 128.9. The estimated planetary A indices were 0, 0, 0, 1, 4, 3 and 3, with a mean of 1.6. The estimated mid-latitude A indices were 2, 2, 2, 3, 6, 5 and 5, with a mean of 3.6.
The solar flux has been climbing over the past week, after a low of 119.6 on December 17. The predicted flux values for the near term are 145 on December 23, 140 on December 24-27, 145 on December 28-30, then dropping suddenly to 120 on December 31-January 2, 125 on January 3-4, 128 on January 5-8, and then peaking at 130 on January 9-17. The predicted planetary A index is 5 on December 23 through January 4, 8 on January 5-6, and 5 on January 7-21. This is from NOAA and the U.S. Air Force Space Weather Operations. There is another opinion, of course: Geophysical Institute Prague predicts quiet conditions December 23, quiet to unsettled December 24, active conditions December 25, unsettled to active December 26, quiet to unsettled December 27 and quiet again on December 28-29.
Active conditions are quite different from an A index of 5, although the NOAA/USAF outlook is at least eight hours newer than the Prague prediction. But looking back 24 hours earlier to the December 21 prediction, USAF/NOAA has nothing different on December 25, although they do show an A index of 8 on December 29. You can check here for the latest prediction, which is updated daily after 2100.
By H. Ward Silver, N0AX ARRL Contributing Editor n0ax@arrl.org Published Date Hits: 425
Category: ARRL
March 04, 2010
Even though you might be an inveterate tinkerer and builder, it's occasionally a good idea to put down those hot irons, sweep off the workbench and turn off the test equipment. This quiz is for you!
1) An Arduino is a type of ________________.
a. transistor array
b. microprocessor prototyping system
c. coax connector
d. Italian vacuum tube
2) Which is most likely to have a "bat handle?"
a. soldering iron
b. rack-mount enclosure
c. toggle switch
d. torque wrench
3) Which connector family is most closely associated with parallel data interfaces?
a. DB
b. USB
c. BNC
d. Centronics
4) What type of holes does a nibbling tool cut?
a. circles
b. squares
c. rectangles
d. irregular
5) What does DIP stand for?
a. Drill In Place
b. Dual Interconnection Pins
c. Dual In Line Package
d. Delta Insertion Point
6) What is the name for the solder composition with the lowest melting point?
a. Acid core
b. Eutectic
c. RoHS
d. Silver-bearing
7) A bipolar switching transistor's fully-saturated collector-to-emitter voltage is ___________.
a. 0.3 V or less
b. 0 V
c. 0.7 V
d. 5 V, +/- 10 percent
8) An op-amp's ability to change output voltage rapidly is called _____________.
a. beta
b. CMRR
c. slew rate
d. open-loop gain
9) What component is used to keep plate voltage out of an amplifier's output matching circuit?
a. Plate Choke
b. Neutralizing Capacitor
c. Bleeder Resistor
d. Blocking Capacitor
10) Which of these is a Germanium diode?
a. 1N28
b. 1N34A
c. 1N914
d. 1N4148
11) Which type of logic element's output is false when both inputs are true or both inputs are false?
a. NAND
b. NOR
c. XOR
d. D-type Flip-Flop
12) Winding parallel wires on a ferrite core is called _____________.
a. bifilar
b. trifilar
c. twisted-pair
d. scramble-wound
Bonus: An "orange drop" would be what type of component?
Answers
1. b -- www.arduino.cc
2. c -- Miniature toggle switches frequently have handles shaped like a baseball bat.
3. d -- Now mostly known as a "parallel port" connector, it was originally developed as a high-speed data interface by Centronics for its printers.
4. d -- A nibbling tool is used to cut irregularly-shaped holes in sheet metal in a series of small, rectangular bites.
5. c -- This is the most common package for through-hole components.
6. b -- Eutectic refers to the mix of metals that melts at the lowest temperature.
7. a -- The exact voltage depends on the circuit.
8. c -- Slew rate is measured in V/µsec.
9. d -- This component passes output RF, but not dc.
10. b -- Germanium is used for its special temperature coefficient and lower forward voltage drop.
11. c -- XOR stands for Exclusive-OR.
12. a -- Bifilar windings are used to balance multiple winding's electrical characteristics.
Bonus: Sprague's "orange drop" film capacitors have been around a long time.