Texas A&M University W5AC The Texas A&M Amateur Radio Club, College Station, Texas
College Station, Texas, U.S.A. • Brazos County • EM10tp

W5AC - Texas A&M Amateur Radio Club
Advanced FAQ

This document answers more advanced questions, like a FAQ for new but already-licensed hams.

  1. Why does everyone call me Roger?
  2. Etiquette - when on ham radio, do as hams do.
  3. What's a handie-talkie? What's a QSO?! (useful definitions)

  4. Where's the volume knob? And other radio inputs.
  5. What does "phone" have to do with repeaters?
  6. What are some different antenna types?

  7. What about tones?
  8. Why is the most popular ham radio mode 2 meter repeater operation?
  9. What is the scale for a signal report?

  10. Is there a reason so many "project boxes" are metal?
  11. Can one really convert a CB radio into a 10 meter ham radio?
  12. Can one really convert a computer modem into a 1200 baud TNC?


  13. Where is that interfering signal coming from?
  14. How do I stop the interference I'm hearing on campus in the 70 cm band?
  15. How can I show up on APRS maps on the internet (without actually transmitting)?

Back to Frequently Asked Questions

1. Why does everyone call me Roger?

"Roger" means the same as "QSL" or "I acknowledge receipt". It doesn't mean you necessarily agree with what they said, but you heard it. It's nice to say "Roger" to start off your sentence so they know you heard them.

Another nice thing to say is "Over" when you're done with your sentence and ready for the other ham to start talking again. This is especially helpful on simplex frequencies (where there's no repeater beep to act as a "Roger") or on big linked repeater nets where many repeaters are tied together, and they stay "open" a few seconds extra so the next sentence doesn't get clipped off at the beginning. Either way, if you don't indicate "Over", everyone listening will hear a whole lot of nothing... every single time you end a sentence.

2. Etiquette - when on ham radio, do as hams do.

Through experience, you'll pick up on the general practices used on the amateur bands, but here's a head-start:

  • Don't overstep the band plan. The ARRL and local amateurs usually work out a plan for what frequencies are used for which modes - a "band plan". This is usually more specific than the FCC-mandated ranges for amateur bands. So, if the band plan says 144.39 MHz is the APRS frequency (packet radio), don't try and speak FM voice on that frequency.

  • Don't "kerchunk" the repeater (transmitting to make it ID itself, then not giving your own callsign). Do listen to see if there is a conversation or net in progress before you transmit on the repeater.

  • Autopatch - before using, give your callsign and say you're going to use the patch. Someone will probably let you know if a net or conversation is in progress, if you give them a heads-up. Don't try to use the patch if others are already talking.

    As with all amateur radio transmissions, phone patch conversations take place over the air. You may have to tell the person on the telephone to conduct themselves accordingly.

    Don't use the patch for frivolous uses like idle chit-chat, and remember that amateur radio MAY NOT BE USED FOR BUSINESS PURPOSES. The purpose of the patch (and the repeater itself) is to pass information useful to amateur radio; you can't just use it to get out of paying the telephone company.

    As with all amateur radio transmissions, give your callsign when you are finished with the patch or ending your conversation (and every 10 minutes if the conversation goes longer than 10 minutes). The custom is to say that you're clear from the patch, just like the custom of using "monitoring" or "clear" explained in the definitions above.

3. What's a handie-talkie? What's a QSO?! (useful definitions)

Here are some useful definitions, ones you'll pick up from talking to other hams.

  • Handie-talkie (HT): a portable radio, with the classic "walkie-talkie" look and relatively low output power
  • QSO: one of many Q codes, this one means "a communication". Q codes are abbreviations that make QSO's faster and easier, especially while using Morse code.

  • 73: "Best wishes", the standard way to end a conversation. For example, "... 73, KD5SYI; this is W5AC, clear".
  • APRS: Automatic Position Reporting System, a popular implementation of packet radio used to transmit location information (like latitude/longitude data from a Global Positioning System (GPS) unit) or short messages
  • Base station: a transceiver radio designed for lots of features and power but not so much for mobility, since it usually stays at the "base"
  • Can: in amateur radio, a type of duplexer found on repeaters
  • Clear: Ending a conversation with your callsign and "clear" means you're not expecting to be on the radio anymore. (see Monitoring)
  • Club: an optional part of an antenna (especially on an HT) that changes what bands the radio can transmit on when it is attached
  • CW: the mode where Morse code is used
  • Digipeater (or "Digi"): a packet radio setup that listens on a simplex frequency, and whenever it hears a packet, it retransmits that information a moment later on the same frequency.
  • Duplex: communication using a "send" frequency and a "receive" frequency, often using a repeater. This way, sending and receiving can be simultaneous. (see Simplex).
  • Duplexer: a device that connects two sources of RF at different frequencies to a single antenna.
  • Elmer: a ham acting as a mentor. Also a verb - "He Elmered the new hams so they could learn such-and-such."
  • EmComm: Emergency Communications.
  • Eyeball QSO: face-to-face communication, no radio required
  • Ground plane: part of an antenna installation that essentially sends the RF energy up, rather than uselessly down into the ground. Often required on vertical antennas to bring SWR down to a usable level.
  • "Health and Welfare" traffic: Comm traffic into a disaster area regarding important but non-urgent health matters and/or meant to enhance the welfare of disaster victims. Typically includes helping families make sure their loved ones in the area are safe.
  • Mobile rig: a transceiver radio designed for a car, usually with more output power than an HT and requiring a plug-in microphone
  • Monitoring: Ending a conversation with your callsign and "monitoring" means you're done with this conversation, but you'll keep listening to the frequency if someone else starts talking. (see Clear)
  • Project box: generic term for a little box housing some helpful little device made as a personal project; popular among ham hobbyists; often metal.
  • QRM: one of many Q codes, this one means "manmade interference". A "pileup" of many hams on one frequency can be considered QRM.
  • QRN: "natural interference (static)"
  • QRP: "low power", or the challenging mode of making QSO's using low power.
  • QRT: "I will stop sending."
  • QRZ?: "Who is calling me?"
  • QSB: "Your signals are fading."
  • QSK: "I can hear you between my signals; break in on my transmission."
  • QSL: "I acknowledge receipt of the message". A QSL card can be exchanged by hams to record a QSO - no two cards are quite the same, and they're fun to collect.
  • QTH: "Location".
  • RF: Radio Frequency, in other words radio waves/energy/modes.
  • Simplex: communication using the same frequency as the other ham, which usually means no repeater. Only one person can transmit at a time. (see Duplex).
  • Standing Wave Ratio (SWR): measure of the impedance match between your radio and antenna system. An SWR of 1:1 is perfect, 2:1 is pretty good, 5:1 or higher is bad. Ignore high SWR and you get two problems - transmission is inefficient, so people can't receive your signal as well, and the energy you lost to inefficiency is now funneled right back down into your radio, physically heating it up until the radio breaks!
  • TNC: Terminal Node Controller, takes digital data in and outputs to a radio; used in packet radio. It's a modem for the radio.
  • Wide-band FM (WFM): transmission mode used by public-broadcast FM radio stations
  • Working ___: Communicating with ___ (fill in the blank). "I am working the repeater right now."
  • XYL: abbreviation for "wife."

4. Where's the volume knob? And other radio inputs.

Audio volume on many radios is labelled "AF", like audio frequency. Here are some other hints to controlling your radio. For more information, always read your radio's manual!

  • "Tone" selects whether or not you want to encode a subaudible tone, often required to use a repeater. Sometimes there are both "encode" and "decode" or "squelch" options.
  • "Offset", another repeater-related button, helps you set up duplex operation - send on one frequency, receive on another. Repeaters almost always have a standard offset in one direction or the other (higher or lower frequency).
  • "ATT" or "Attenuate" limits the sensitivity of the receiver by some number of decibels; useful when there are strong RF emissions that are physically nearby or that are on a frequency close to what you're using; when using the shack HF rigs, USE this to prevent KANM transmissions from overloading the radio!
  • "VFO/M" usually switches between the Variable Frequency Oscillator (change frequencies up or down freely) and memorized frequencies stored in memory locations of the radio.
  • "Mic" lets you set the sensitivity of your microphone so you don't sound muffled or otherwise distorted over the air.
  • "RF PWR" or "Low" will let you vary how much power your radio is transmitting into your antenna cabling. Don't use more than you need, but if you can't be heard, maybe you should increase your power some.
  • "Squelch" lets you ignore static but still hear people when they transmit. The level of squelch decides how sensitive the radio is to static, and what you can hear out the speaker.

5. What does "phone" have to do with repeaters?

Most repeaters, like our 146.82 machine, are FM Phone mode repeaters. This refers to the use of a microphone.

Another type of repeater is a digipeater, or as we refer to ours, a "digi". These repeaters send and receive packet radio "packets" of data. Interesting fact - due to the small size of APRS packets, the digi doesn't need to be full-duplex like a voice repeater. It can use 1 frequency instead of 2, and can even modify the packets it re-transmits to take advantage of APRS wide-area relaying features.

A telephone line comes into play with the "autopatch." Also called a "phone patch," this allows an amateur radio operator using the repeater to make a phonecall. The phone line is connected to the repeater; therefore, don't expect to make a long-distance call. See etiquette for more.

6. What are some different antenna types?

Here are several of the more popular styles:

  • Vertical - basically a pole sticking straight up. They are omnidirectional, meaning they transmit/receive equally well in all directions. Magnet-mount verticals are often used on cars. HT's have a built-in vertical antenna, and base stations often include a vertical installed high on a pole or tower.
  • Vertical (or horizontal) Beam - also called a Yagi antenna
    • they are directional antennas (pointed in a particular compass direction; usually parallel to the ground). You can transmit/receive more power/gain in one direction, and less from other directions, compared to omnidirectional antennas.
    • they are made of one long piece with many short pieces running perpendicularly across the long piece (the short pieces point horizontally or vertically depending on which type it is; a horizontal beam is a vertical beam "on its side")
    • Rule of Thumb - Horizontal for Single Sideband, Vertical for everything else.

      If one party is mismatched from the other, i.e. the transmitter is vertically polarized and the receiver is horizontally, the signal strength drops by something like 20 decibels.
  • Cross-polarized Beam - just like the other kinds of beam but with an "X" pattern to the short pieces, making it both vertically and horizontally polarized. Good for working satellites.
  • "Barbecue Grill" Dish, which looks like a mesh of wire formed in a curved shape, like you could roast hot dogs on it. Used for really really high frequencies, like 2 GHz, where the small size of the dish is a significant fraction of the wavelength.
  • Dipole, which is simply a pair of wires stretched out from a "feed point", making it a simple, cheap, and reliable antenna. It is somewhat directional.
    • the G5RV - a special dipole
  • Discone, which has a vertical element pointing up and a "cone" of elements pointing about 60 degrees down from horizontal. Often used for scanning widely-separated frequencies.
  • TVRO satellite dish, for Television Receive Only. This is the old, large size dish, not the 18 inch kind.
Antenna design is a massive topic all by itself. Check out the ARRL books on the subject, or search online and you'll find a wide variety of antenna designs.

7. What about tones?

When a ham talks about "tone," it is generally a reference to subaudible tones. These are transmitted in the audio signal, but at low audio frequencies around 100 or 200 Hertz (the lower the frequency, the less likely to bother listening hams).

Tones go by several names - CTCSS (Continuous Tone Coded Squelch Systemn), the generic name; PL (Private Line), the trademarked name of Motorola's tone system for business radios; QC (Quiet Channel), RCA's name for it; and CG (Channel Guard), General Electric's name for it. They are all the same idea - a subaudible tone transmitted with the voice.

Why would anyone do such a thing? The answer is to differentiate between different users of the same frequency. The most common use for subaudible tones in amateur radio is for repeater access. A repeater will only allow a signal that includes the tone to be transmitted by that repeater. Therefore, random, noisy signals won't activate the repeater; neither will users of a distant repeater on the same frequency but with a different tone. "Open" repeaters (open to use by any ham) usually use tone just to keep out noise. "Closed" repeaters can limit repeater use to certain members by only letting members know the correct tone. The amateur operator is the one encoding the tone into the transmission.

On the other hand, the operator might decode a tone, too. In this case, the repeater encodes a tone; then whoever wants to receive the signal from this repeater - and not a signal from other repeaters - can set up "tone squelch" to ignore the frequency unless the receiver hears that tone. This "tone decoding" can also be used between multiple users of one simplex frequency, and as long as no one transmits at exactly the same time, separate parties can each use the frequency without bothering other parties.

Hint - if you have trouble transmitting into a repeater, and you're sure you ought to be able to, check your tone encode/decode settings. If you think you're encoding and decoding, try just encoding. This author has made the mistake of assuming that his radio can do both at the same time with different tones, when in fact it is an either encode/or decode/not both on his radio.

8. Why is the most popular ham radio mode 2 meter repeater operation?

The entry-level ham license includes 2 meter privileges (including building repeaters). The first radio transmission for many new hams is on a local 2 meter repeater. The most inexpensive radios seem to be handie-talkies on... 2 meters! Repeaters for this band seem to be everywhere. The 2 meter band works well for local communications and stays exciting when "tropo-ducting" conditions allow for longer range QSO's.

9. What is the scale for a signal report?

Signal reports are often exchanged during HF QSO's. They are given Readability of the audio followed by RF Signal Strength (optionally followed by decibels over the 9 rating), like: "Your signal report is 5 by 9 plus 20 decibels."

10. Is there a reason so many "project boxes" are metal?

Yes.

Besides being durable and common, metal as a box-building material offers RF shielding. When you take your project near a strong HF transmitter (like one finds during Field Day), RF may get into the electronics of the project if the box doesn't have some sort of shielding. A metal box has some inherent sheilding... induced current and such will flow _around_ the project rather than in it.

Do they have to be metal? Nope! Whatever works.

11. Can one really convert a CB radio into a 10 meter ham radio?

Maybe, but it's a messy project probably not worth it. Among other changes, you would have to make many tiny adjustments to potentiometers and such within the radio.

12. Can one really convert a computer modem into a 1200 baud TNC??

Maybe, but it's a messy project probably not worth it. Even if you do get the hardware to "talk" the talk of 1200 baud AX.25 protocol, a modem won't have the built-in software that a TNC does that, among other things, correctly transmits your callsign.

13. Where is that interfering signal coming from?

One of the more frequent sources of interference on the 2 meter band is part of a computer (a PC, a server, or something similar). You're monitoring the local repeater as you go to start the computer, and when you hit the computer power button, you hear noise on the radio. Or, you hear noise on the radio as you pass a certain room each day. This is called a "birdie", and though it's annoying, it is usually only noticeable when the antenna is very close to the offending computer, and nothing else is transmitting on the frequency.

14. How do I stop the interference I'm hearing on campus in the 70 cm band?

There is a powerful 70 cm repeater on campus. Sometimes other repeaters near that frequency become difficult to monitor, because something "mixes" with the frequency of the powerful repeater and opens the squelch of radios monitoring the other repeaters.

Most of the area repeaters not only use CTCSS subaudible tones for keying up the repeater, they also encode a tone into the repeater's transmission, so radios can be set to ignore signals that don't have that encoded tone (signals like mixing interference or static). This is called "tone squelch". Radios using this feature can scan through the repeater frequencies like normal, but only stop to open the squelch if the signal is actually coming from that repeater.

Attenuating the received signal helps, too. Many radios have "ATT" buttons for this, and there are also other ways to "muffle" the signal.

15. How can I show up on APRS maps on the internet (without actually transmitting)?

There are a couple of different ways to do this. One way is inputting positions through the popular findu website. Another is using APRS software, such as Xastir (for Linux) or WinAPRS, MacAPRS, UIView, etc. to connect to the APRS Internet servers. The latter way lets you choose what icon to display at your position on the map.

More questions and answers coming in the future.

© W5AC, The Texas A&M Amateur Radio Club