1. 1 Technician Licensing Class These Power Point presentations are available to individuals who register with The W5YI Group’s HamInstructor.com program. The presentations are provided by Master Publishing and The W5YI Group and include material that is covered by U.S. and International copyrights. They are intended solely for the use of Registered Instructors using the Gordon West, WB6NOA, Technician Class, General Class, and Extra Class study manuals to teach FCC Amateur Radio Licensing Classes. Registration through HamInstructor.com constitutes a Licensing Agreement between The W5YI Group and the registered instructor under which the instructor agrees not to copy or distribute the Power Point presentations to unauthorized users.

2. 2 Technician Licensing Class Run Some Interference Protection Valid July 1, 2014 Through June 30, 2018

3. 3 3 Amateur Radio Technician Class Element 2 Course Presentation  ELEMENT 2 SUB-ELEMENTS (Groupings) About Ham Radio Call Signs Control Mind the Rules Tech Frequencies Your First Radio Going On The Air! Repeaters Emergency! Weak Signal Propagation

4. 4 4 Amateur Radio Technician Class Element 2 Course Presentation  ELEMENT 2 SUB-ELEMENTS (Groupings) Talk to Outer Space! Your Computer Goes Ham Digital! Multi-Mode Radio Excitement  Run Some Interference Protection Electrons – Go With the Flow! It’s the Law, per Mr. Ohm! Go Picture These! Antennas Feed Me With Some Good Coax! Safety First!

5. 5 5 Run Some Interference Protection T7B10 This particular question about a poor signal report from your radio through a repeater has a correct answer showing all of the conditions that might lead to this bad reception. Likely, a bad location in one of those “not spots” could lead to a distorted or weak signal, so try moving to a slightly different location where the signal strength of the repeater shows greater on your handheld LCD graph, and that should probably be a better spot from which you can transmit through the repeater.

6. 6 6 Run Some Interference Protection T4B01 Some base station radios for weak signal VHF and UHF operation have a microphone gain control. Set the control at about half scale. Turning the control wide open will set the mic gain too high and cause the transmitted signal to become distorted. T7B01 If your set is over-deviating, it means that too much modulation is driving your signal beyond its normal bandwidth. If you talk farther away from the microphone, you will minimize or even eliminate the over-deviation.

7. 7 7 Run Some Interference Protection T2B07 Having your microphone gain set too high will cause excessive deviation and is the primary cause of an FM transmitter using up too much spectrum space. While most modern handheld and portable rigs have deviation limiters, these can get out of adjustment. If someone tells you that you are over-deviating, simply back off from the microphone an inch or two, which will reduce the modulation until you can get your radio fixed! Learning how to adjust your radio’s deviation is a technical skill every Technician should learn, as a bare minimum. (You ARE called a TECHNICIAN after all, aren’t you?)

8. 8 8 Run Some Interference Protection T4B05 On that multi-mode, weak-signal radio when you receive a weak single-sideband signal, turn on the noise blanker to minimize ignition noise. There is no noise blanker function on a common FM handheld or mobile radio, just on your bigger high-frequency, multi-mode transceiver. T4A10 You have that brand new mobile radio installed in that brand new car (you rewarded yourself for passing the test), but each time you goose the accelerator you hear a high-pitched whine coming out of your mobile radio speaker! This is most likely alternator whine, and can be minimized with DC filter chokes and alternator filters.

9. 9 9 Run Some Interference Protection T4A12 This is a common problem with a handheld plugged into the 12 volt accessory socket in your automobile. If your automobile has a hefty alternator charging system without filters on the leads, the AC from the alternator will put a high pitch whine on your transmit and receive signal. If you hear a singing noise that changes as you accelerate and then comes back down in pitch as you let off the gas, plan to buy some DC noise filters and put them on both the electrical system as well as on your handheld 12-volt DC input cord. Most car adaptor plugs for handhelds have built-in noise chokes to minimize this common problem.

10. 10 Run Some Interference Protection T4A09 RF (radio frequency) current flowing on the outside of microphone cables (and other conductors as well) is generally of the common mode sort, which is normally most effectively cured by the use of ferrite beads or cores surrounding the conductor, thus “choking” off the RF current. Sometimes reducing RF problems is a bit of an art form, but always start with the “standard” fixes first. If you plan to go digital with your new Technician Class privileges, load up on a handful of ferrite chokes. These are clamshell iron devices that simply snap on over the wiring coming from your handheld or mobile radio to your computer. The ferrite choke will minimize RF currents flowing on the shield of an audio cable. You want everything on the inside, not the outside!

11. 11 Run Some Interference Protection T7B12 In any interference case, you want to be sure you have a “clean house” to start with. Assuming you are transmitting a clean signal, this situation indicates cable leakage, which can result from any one of possibly dozens of improperly installed cable connectors in a cable TV installation.

12. 12 Run Some Interference Protection  T4A04 Now that television signals are digital, and the majority are now transmitted over-the-air on UHF frequencies, ham radio television interference (TVI) is a rarity. Your worldwide radio already has a low pass filter installed to remove harmonics. On the VHF and UHF ham bands, no filter should ever be added to your antenna system. But to answer this question correctly, if you decided to add a low pass filter on the antenna connection of your worldwide radio, it goes between the transmitter and the antenna.

13. 13 Run Some Interference Protection T7B03 You are outside sitting in your deck chair listening to your local repeater when, all of a sudden, your handheld picks up nothing but hash. Your buddy across the street (also a ham) is transmitting with a mobile radio and amplifier that he bought off a swap net that was advertised as “may need some tweaking.” That nearby transmitter is probably overloading your receiver with harmonics and spurious emissions, and all of this leads to radio frequency interference. Don’t buy questionable used gear – Marconi himself probably couldn’t fix it.

14. 14 Run Some Interference Protection T7B11 You are on 6 meters for the first time, and signal strength tests with hams a few miles away indicate you have a strong signal, but your modulation (your voice) is slightly garbled. This is most likely caused by RF feedback between your antenna system and the microphone. You have the antenna temporarily set on a tripod, just a few feet away from your operating station. Get some longer coax, move the antenna at least 15 feet away from your operating station, and likely your friends will tell you the distortion has cleared up. No more RF feedback!

15. 15 Run Some Interference Protection T6D12 All electrical conductors are capable of both radiating and receiving radio frequency energy. This is great in the case of an antenna; it’s not so great in most other applications. When you don’t want a conductor to radiate or receive radio signals (or other interference), the use of shielding is often an effective solution. The most familiar shielded wire is coaxial cable, but there are also variations on the theme. Some commercial shielded lines are known as Twinax, Triax, as well as a few others.

16. 16 Run Some Interference Protection T7B06 It’s unlikely that VHF and UHF signals will cause television interference to your neighbors on an outside antenna, or on the dish or on cable. However, if you go on the worldwide bands using your Morse code privileges, be aware that these frequencies could sneak into a television set and cause problems. First, double check that your equipment is well grounded and operating properly, and double check that your TV is working okay when you are transmitting over the air. If it is, chances are your neighbors may have some loose connections on their TV receivers, and this should be cured as a step toward reducing the interference from your station when transmitting on high frequency.

17. 17 Run Some Interference Protection T7B02 Interference between Amateur Radio and other radio services has always been a potential problem, though in many regards it’s not as severe as it once was. As broadcast TV signals changed from analog to digital, the “disappearance” of Channel 2 TV, for instance, has made full power 6-meter amateur radio a joy in recent years, where in the past it was almost certain to cause interference to nearby analog TVs on that channel. In any case, it behooves any amateur to understand some rudiments of preventing or curing various forms of RF interference as they might crop up. Often, however, the problem is design defects in the consumer electronic device. A small degree of wisdom (or a lot of experience) is often necessary to resolve these issues. Each case is a special case.

18. 18 Run Some Interference Protection T7B04 You can purchase snap-on ferrite chokes that act as an RF filter on the telephone equipment. Snap these filters over the telephone power cord, curly cord, and on the actual incoming telephone line cord. The more snap-on filters you add, the less likely your little handheld or base station will cause interference.

19. 19 Run Some Interference Protection T7B07 The best way to correct radio frequency interference from your ham radio to your mother-in-law’s hi-fi and ancient black and white analog TV is to use snap-on ferrite chokes, and rely on your own equipment’s band pass filters to keep your transmit signal clean. Hopefully, that old TV set has its own high pass filter built in. For the worldwide ham bands, newer ham rigs have low-pass filters built in and, in rare cases, you could actually build a “shorted stub” band reject filter for that old TV set. For the exam, all of these choices are correct, but in the real world of ham radio, the very best way of eliminating your lovely voice coming over you mom-in-law’s hair dryer and toaster would be snap-on ferrite chokes, especially useful on computer leads, telephone modems, hi-fi connections, and on incoming telephone lines and the telephone handset. A good ham has a 5 pound bag of ferrite chokes ready for any interference problem! But for the exam, go with all of the answers!

20. 20 Run Some Interference Protection

21. 21 Run Some Interference Protection T7B05 Unfortunately, a lot of consumer equipment is designed and built as if they were the only occupants of the radio spectrum. No matter how pristine and clean your amateur radio signal is, some types of interference, such as front end overload, can only be fixed at the consumer’s equipment. This is just one such case. Consult the ARRL Handbook or other reputable references for detailed information on how to apply filters to the consumer gear for this solution.

22. 22 Run Some Interference Protection T7B09 Part 15 devices are unlicensed devices that use low-power radio signals. They are prohibited from causing interference to other licensed devices (such as amateur radio) and must accept any interference from duly licensed transmitters, Amateur or otherwise. Fortunately, interference from Part 15 devices to amateur radio is relatively rare, but you need to know they’re out there!

23. 23 Run Some Interference Protection T7B08 A wireless anything is likely rated a Part 15 device, and this means the potential of ham radio interference. My neighbor’s wireless weather station sometimes clobbers my weak signal work on 432 MHz. And when I transmit moonbounce, another neighbor reports his wireless doorbell goes bing-bong. As more wireless Part 15 devices switch from analog to digital, our ham transmitters probably won’t disturb them anymore. However, it’s good to take stock of what you may have around the house that is a Part 15 device, and if you have a pesky weird sound on a certain 2 meter frequency, see if that particular device is causing it. Part 15 devices going digital is good for minimizing ham radio interference! All these choices are correct.

24. 24 Run Some Interference Protection Element 2 Technician Class Question Pool Valid July 1, 2014 Through June 30, 2018

25. 25 T7B10 What might be the problem if you receive a report that your audio signal through the repeater is distorted or unintelligible? A.Your transmitter may be slightly off frequency B.Your batteries may be running low C.You could be in a bad location D.All of these choices are correct

26. 26 T4B01 What may happen if a transmitter is operated with the microphone gain set too high? A.The output power might be too high B.The output signal might become distorted C.The frequency might vary D.The SWR might increase

27. 27 T7B01 What can you do if you are told your FM handheld or mobile transceiver is over- deviating? A.Talk louder into the microphone B.Let the transceiver cool off C.Change to a higher power level D.Talk farther away from the microphone

28. 28 T2B07 What could cause your FM signal to interfere with stations on nearby frequencies? A.Microphone gain too high, causing over-deviation B.SWR too high C.Incorrect CTCSS Tone D.All of these choices are correct

29. 29 T4B05 Which of the following would reduce ignition interference to a receiver? A.Change frequency slightly B.Decrease the squelch setting C.Turn on the noise blanker D.Use the RIT control

30. 30 T4A10 What is the source of a high-pitched whine that varies with engine speed in a mobile transceiver’s receive audio? A.The ignition system B.The alternator C.The electric fuel pump D.Anti-lock braking system controllers

31. 31 T4A12 What could be happening if another operator reports a variable high-pitched whine on the audio from your mobile transmitter? A.Your microphone is picking up noise from an open window B.You have the volume on your receiver set too high C.You need to adjust your squelch control D.Noise on the vehicle’s electrical system is being transmitted along with your speech audio

32. 32 T4A09 Which of the following could you use to cure distorted audio caused by RF current flowing on the shield of a microphone cable? A.Band-pass filter B.Low-pass filter C.Preamplifier D.Ferrite choke

33. 33 T7B12 What might be the first step to resolve cable TV interference from your ham radio transmission? A.Add a low pass filter to the TV antenna input B.Add a high pass filter to the TV antenna input C.Add a preamplifier to the TV antenna input D.Be sure all TV coaxial connectors are installed properly

34. 34 T4A04 Where must a filter be installed to reduce harmonic emissions from your station? A.Between the transmitter and the antenna B.Between the receiver and the transmitter C.At the station power supply D.At the microphone

35. 35 T7B03 Which of the following may be a cause of radio frequency interference? A.Fundamental overload B.Harmonics C.Spurious emissions D.All of these choices are correct

36. 36 T7B11 What is a symptom of RF feedback in a transmitter or transceiver? A.Excessive SWR at the antenna connection B.The transmitter will not stay on the desired frequency C.Reports of garbled, distorted, or unintelligible transmissions D.Frequent blowing of power supply fuses

37. 37 T6D12 Which of the following is a common reason to use shielded wire? A.To decrease the resistance of DC power connections B.To increase the current carrying capability of the wire C.To prevent coupling of unwanted signals to or from the wire D.To couple the wire to other signals

38. 38 T7B06 Which of the following actions should you take if a neighbor tells you that your station’s transmissions are interfering with their radio or TV reception? A.Make sure that your station is functioning properly and that it does not cause interference to your own radio or television when it is tuned to the same channel B.Immediately turn off your transmitter and contact the nearest FCC office for assistance C.Tell them that your license gives you the right to transmit and nothing can be done to reduce the interference D.Install a harmonic doubler on the output of your transmitter and tune it until the interference is eliminated

39. 39 T7B02 What would cause a broadcast AM or FM radio to receive an amateur radio transmission unintentionally ? A.The receiver is unable to reject strong signals outside the AM or FM band B.The microphone gain of the transmitter is turned up too high C.The audio amplifier of the transmitter is overloaded D.The deviation of an FM transmitter is set too low

40. 40 T7B04 Which of the following is a way to reduce or eliminate interference by an amateur transmitter to a nearby telephone? A.Put a filter on the amateur transmitter B.Reduce the microphone gain C.Reduce the SWR on the transmitter transmission line D.Put an RF filter on the telephone

41. 41 T7B07 Which of the following may be useful in correcting a radio frequency interference problem? A.Snap-on ferrite chokes B.Low-pass and high-pass filters C.band-reject and band-pass filters D.All of these choices are correct

42. 42 T7B05 How can overload of a non-amateur radio or TV receiver by an amateur signal be reduced or eliminated? A.Block the amateur signal with a filter at the antenna input of the affected receiver B.Block the interfering signal with a filter on the amateur transmitter C.Switch the transmitter from FM to SSB D.Switch the transmitter to a narrow-band mode

43. 43 T7B09 What is a Part 15 device? A.An unlicensed device that may emit low powered radio signals on frequencies used by a licensed service B.A type of amateur radio that can legally be used in the citizen’s band C.A device for long distance communications using special codes sanctioned by the International Amateur Radio Union D.A type of test set used to determine whether a transmitter is in compliance with FCC regulation 91.15

44. 44 T7B08 What should you do if something in a neighbor’s home is causing harmful interference to your amateur station? A.Work with your neighbor to identify the offending device B.Politely inform your neighbor about the rules that prohibit the use of devices which cause interference C.Check your station and make sure it meets the standards of good amateur practice D.All of these choices are correct