1965 Ham License Answers

Novice:

1. Question #9: What method of frequency control is required to be used in the transmitter of a station licensed to the holder of a Novice Class License? The frequency must be crystal-controlled.
2. Question #13: What is the maximum permissible percentage of modulation of an amateur radiotelephone station? 100%
3. Question #17: What is the relationship between a fundamental frequency and its second harmonic; its third harmonic, etc.? The second harmonic is twice the frequency of the fundamental, the third harmonic is three times the fundamental frequency, and so on. A harmonic is always related to its fundamental frequency by an integral multiplier; i.e., 2, 3, 4, 5, 6, etc.
4. Question #23: How is the actual power input to the tube or tubes supplying energy to the antenna of an amateur transmitter determined? The input power is determined by measuring the direct-current plate oltage and the d.c. plate current to the tubes in the final stage in the transmitter. The power input is equal to the plate voltage multiplied by the plate current in amperes.
5. Question #27: What is meant by a "parasitic" oscillation? A parasitic oscillation is one not essential to the operation of the equipment and usually occurring on a frequency considerably removed from the operating frequency.

General:

1. Question #1: Name the basic units of:
   • electrical resistance - ohm
   • inductance - henry
   • capacitance - farad
   • current - ampere
   • electromotive force or potential difference - volt (electromotive force is a fancy term for "voltage")
   • power - watt
   • energy - joule
   • quantity - coulomb
   • magneto-motive force - gilbert
   • frequency - cycles-per-second, or cycles (nowadays known as "hertz")
    
2. Question #10: What is the principal reason for using a filter in a plate power-supply system? The principal reason for using a filter in a plate power-supply system is to smooth out the a.c. ripple component in the output and make it "pure d.c."
3. Question #19: What undesirable effects may result from operation of an unneutralized triode r.f. amplifier in a transmitter? Self-oscillation may result, with consequent radiation on undesired frequencies, possibly outside an amateur band.
4. Question #69: What is meant by a "doubler" stage? A vacuum-type circuit in which the output circuit is tuned to twice or doube the frequency of the input circuit.
5. Question #71: What is the reciprocal of resistance? Conductance, measured in mhos ("ohms" spelled backwards)
6. Question #106: What precaution should be taken to protect filter capacitors connected in series? Resistors having a value of approximately 100,000 ohms should be shunted across each capacitor to equalize the d.c. voltage drops and thus prevent breakdown of the individual capacitors.

Extra:

1. Question #4: What factors determine the core losses in a transformer? Core losses are one of two types, hysteresis and eddy-current losses. Hysteresis losses vary with the type and volume of iron or steel used in the core and with the operating frequency and magnetic flux density. Eddy-current losses vary with the volume and resistance of the core material, the thickness of the laminations, and frequency and the flux density.
2. Question #7: In a Class-C r.f. amplifier, what ratio of load impedance to dynamic plate impedance will give the greatest plate efficiency? The highest possible load impedance will give the greatest efficiency, since the ratio of the power in the load to power lost in the plate becomes larger as the ratio of load impedance is increased. However, under these conditions, the power output is relatively small.
3. Question #12: During 100 percent sinusoidal amplitude modulation, what percentage of the average output power is in the sidebands? 33 1/3% The average power output would increase 50% with such modulation; i.e., a 100-watt unmodulated carrier output would rise to 150 watts. Sidebands carry the excess of 50 watts, which is 1/3 the total.
4. Question #25: What are synchronizing pulses as used in television transmitters and receivers? Synchronizing pulses used in television transmitters and receivers are pulses of extremely short duration which ensure that trace lines across the face of the picture tube in the receiver are synchronized with the trace lines in the television camera.
5. Question #34: What determines the operating frequency of a magnetron oscillator? Its dimensions and the electric and magnetic field intensities; also, the associated circuit constants.
6. Question #46: If the conductors in a 2-wire r.f. transmission line are replaced by larger conductors, how is the surge impedance affected, assuming no change in the center-to-center spacing of the conductor? The surge impedance is lowered.
7. Question #63: What is the purpose of the mosaic plate in a television camera? To what item of photographic equipment is it similar in function? To store an electrical image corresponding to the visual image focused upon it, for later scanning by an electron beam to translate the electrical image into a television signal. Its function is similar to that of the film in a photographic camera, which similarly stores the image for later development.
8. Question #92: What are the "Baudot" and "Seven Unit" codes? How are they used? Both are used in teleprinter operation. Baudot used with synchronous printers, 7-unit with start-stop printers. Each transmitted character has assigned to it a fixed time interval divided into units, 5 for Baudot and 7 for 7-unit teletype. A particular character is distinguished by a unique combination of mark and space units in that particular codes being used in all cases.
9. Question #120: What is the meaning of the term "frequency swing" in reference to frequency-modulation transmitters? The peak difference between the maximum and minimum values of the instantaneous frequency.
10. Question #136: What is the ohms per volt of a voltmeter constructed of a 0-1 d.c. milliammeter and a suitable resistor which makes the full-scale reading of the meter 500 volts? 1000 ohms per volt.
11. Question #181: What is meant by low-level modulation? That applied to an early or intermediate stage of a transmitter (instead of to the final amplifier) i.e., at a point where the power level is comparatively low.
12. Question #204: State where antenna impedance is usually measured. At the point where the antenna is fed. The value so measured is frequently converted into an equivalent value at a current loop.
13. Question #219: Define a "back-wave" and explain what causes it. A signal emitted during key-up conditions. In make-break keying, it may be caused by energy from unkeyed exciter stages leaking through a keyed amplifier (because of improper neutralizations, etc.) or by parasitic oscillation. In frequency-shift keying the "space" signal in the back-wave.

Geminids meteor shower pretty active

I went outside Thursday night in the chilly weather around midnight and the Geminids meteor shower was in full swing. I witnessed a few dozen before having to go to bed.

I'm still trying to find a frequency I can listen to in order to "hear" the meteors as they come into Earth's atmosphere. I posted about my search some time ago and still haven't gotten any success in locating a good frequency to listen.

It was suggested I try an empty National Weather Service frequency for NOAA weather radio, but where I live all available NWS frequencies are in use, either from Morristown or Nashville, and my antennas pick up the ones off in the distance and so any NWS frequency I tune into I can hear something enough to where any attempt to listen is futile.

Since the FCC transition to digital, there are not major TV stations that I can tune in, and the low-power TV stations that remain I couldn't hear, but then again I don't see any listings for said low-power TV stations in adjacent cities.

I'll keep searching, but in the meantime here's a blurb about meteor scatter on boingboing.

Trip to Clingman's Dome, discovering SOTA

The view from Clingman's Dome at sunset

I hope everyone had a happy Memorial Day weekend. It's good to take pause and remember that many brave men and women paid the ultimate price for all of us Americans to freely express ourselves and enjoy the lives we live day in and day out.

I decided to take the family up into the mountains and watch a sunset from Clingman's Dome in the Great Smoky Mountains National Park Monday. We were supposed to go on Sunday but plans didn't work out (as they never do with me!). 

When we got I pulled out my trusty Wouxun 2m/220 radio and attempted to make some contacts on 6.52 simplex but, unlike 2 weeks ago when I went up to "the Dome", there was no one willing to talk. 

As I trekked up the steep path to the overlook I made a couple of quick QSOs with locals on a repeater, and stowed my radio for use from the observation tower. As we got to the base of the ramp leading up to the tower, I looked up and saw a rotatable dipole jutting out from the side of the dome. I quickly realized someone else on the tower had a ham ticket and was tearing it up on HF!

W3FF Buddipole

I got to the top and met up with Lynn, KJ4ERJ who was visiting from Florida. I asked about his operation and he told me he was working "SOTA", or "Summits on the Air". It was the first I've heard of such a program (even though I've been a ham for 18-1/2 years) but sounded very interesting.

I was offered a chance to operate but declined. I was having enough fun enjoying listening to the contacts coming in from New Mexico, New York, Florida, Arizona, and New Jersey on his Yaesu FT-817.

I tried simplex again and wasn't successful. I made a couple more repeater contacts and stayed long enough to realize that the sunset I had hoped to view was lost to the clouds off to the west.

Lynn and his son Paul, KJ4DXK were hammering out contact after contact on the rotatable dipole (set up for 20m meters) and I had to find out more about the antenna. I discovered it was a "buddipole" and watching it in action showed its value, as Paul and Lynn continued to rack up contact after contact on 2.5W, getting 5/9 reports from almost everyone.

KJ4ERJ working a contact on 20m

I tried to drum up a few contacts for them by sending a message to my Twitter account, but I forgot, I'm on TOP OF A MOUNTAIN, and cell phone coverage didn't exist. Unfortunately I couldn't raise anyone on the repeaters in order to spread the word about their operation. Talk about bad timing!

Summits on the Air (according to their web site) is "an award scheme for radio amateurs and shortwave listeners that encourages portable operation in mountainous areas. SOTA has been carefully designed to make participation possible for everyone...There are awards for activators (those who ascend to the summits) and chasers." It sounds like something I need to investigate at some point. This may soon become another pet project!

The weather atop Clingman's Dome is some of the most hostile and unpredictable I've ever encountered. I've been up to the Dome numerous times, typically to stargaze after dark and on occasion to take my ham gear up and work some contacts, though it's typically on VHF. I've been up to watch meteor showers, join an astronomy party, and of course, enjoy the view. But you do need to dress warm for the trip. Memorial Day it was 95 degrees at my house, but when we got to the Dome, it was 60. And as the sun went behind the clouds to the west, the constant wind at the tower added a chill to the air that made us beat a hasty retreat back to the car.

One evening my wife and I ventured up to the Dome's parking area to watch a meteor shower, and it was one of the clearest views I've ever had of the stars. Then we go back a week later, and the weather in Knoxville is clear and dry, but high up on the mountain, when we arrived at Newfound Gap, just before getting onto the 7-mile road to the Dome, a thunderstorm brewed up from nowhere and made for a treacherous retreat from the mountain...back to a clear and dry Knoxville. More often than not, it's clear everywhere BUT the Dome, and when I arrive in the parking area, it's nothing but fog.

Still, going up to Clingman's Dome is well worth the trip. Whether it's to stargaze, enjoy the view, or work a few radio contacts, it's guaranteed to be an adventure.

Heinrich Rudolf Hertz: Google Doodle for a guy who rode a wave

Google's doodle honoring Hertz

Google put up an animated doodle of their logo honoring the 155th birthday of Heinrich Hertz. The animated logo doodle was posted on Wednesday, February 22, 2012.

Here's more from the LA Times:

Heinrich Rudolf Hertz -- who, like Van Gogh and Mozart, was a rare genius not fully appreciated during his lifetime -- is honored with a Google Doodle today, his 155th birthday. And perhaps the reason the German physicist wasn't valued for his work was that no one at that point was smart enough to do so.

Even Hertz didn't get it.

The German physicist, who was the first to broadcast and receive radio waves, did not realize at the time the broader implications of his work -- which laid the groundwork for the invention of the wireless telegraph, radio and TV.

"I do not think that the wireless waves I have discovered will have any practical application," Hertz once wrote, according to Scotland's University of St. Andrews.

Hertz made his discoveries young -- he began exercising his smarts early and was beginning his groundbreaking work at age 28. But his life was short, likely depriving the world of a host of amazing efforts. 

Contemplating the accomplishments he did make is enough to give those with more average brains a headache.  

He was the first to broadcast and receive radio waves, and he established "beyond any doubt" that light and heat were electromagnetic radiations.

Read more here.