Facts Supporting the Extra Class License Exam

I’m studying for the Amateur Extra Class license exam. I want to pass, but I’m not seeking a perfect score. (Perfection is not an effective use of my time.) I’m willing to memorize facts but not answers. The difference is that a fact is something useful after the exam.

However, I will memorize an occasional answer or write-off a question if the amount of learning is enormous just to answer a few questions.

These are just the things I have to learn. I’m not capturing things I already know, such as Ohms law.

https://hamstudy.org/extra2012 (the “Read Questions” link) is very helpful. Many of the questions have explanations associated with the answers.

  • Reminder: micro and mega both deal with a million (106). Pico is million million (1012).
  • Circulator - a three- or four-port device, in which an RF signal entering any port is transmitted to the next port in rotation (only).
  • Receiver performance measures
    • MDS = Minimum Discernable Signal
    • Dynamic range = space between weakest signal radio can receive and strongest it can handle w/o excess distortion.
    • Desense (a.k.a. blocking) = close frequency at strong level drives RF amp to compression (non-linear behavior).
      • Narrowing receiver bandwidth reduces this because “close” means within the receiver passband.
    • Cross-modulation = modulation of a close frequency superimposes on desired frequency.
    • Phase noise in the local oscillator of a receiver can mix with nearby frequencies to interfere with the tuned frequency. (It creates a signal that mixes with the nearby frequency.)
    • Blocking Dynamic Range = dB between noise floor and incoming signal level which will cause 1 dB of gain compression. In effect, it is the signal strength range the receiver can handle.
  • Intermodulation
    • Intermodulation products are the emissions at frequencies generated by the combination of two or more frequencies in a non-linear device, such as the output stage of a transmitter, or the input stage of a receiver (or corroded connections). E.g. (f1 - 2*f2). Mixing often occurs in a non-linear RF amp.
    • A circulator reduces intermod by preventing signals received in the transmitting antenna going back into the transmitter amplifier and mixing.
  • 3rd order intercept
    • a 3rd order intercept of x db means that a pair of signals will theoretically generate a third-order intermodulation product with the same level as the input signals
    • 3rd order intermod products created within a receiver are of interest because the 3rd order product of two signals in the band of interest is also likely to be within the band
  • Resonance
    • At resonance, the L and C components of an RLC circuit go to zero, leaving only R.
    • In series, when L and C cancel, you have lower total RLC impedance, so more current flows. (This is like removing 2 of 3 resistors that are in a series. R goes down.)
    • In parallel, when L and C cancel, you have higher impedance between the two rails, so less current flows. (This is like removing 2 of 3 resistors that are in parallel. R goes up.)
    • L and/or C shift the phase between voltage and current in opposite directions. Ergo, at resonance, there is no shift because AC circuits that are resistive have no phase shift.
    • F = .159 / sqrt(LC)
      • Note: This is true when the units on L and C are similar. (e.g. Farads and henries, or micro-farads and micro-henries.) On the exam, they mix micro-henries with pico-farads, so you use: F = 1000 * .159 / sqrt(LC).
        • i.e. On the exam, calculate F = .159 / sqrt(LC) without regard for units, and then multiply by 1,000
  • Time constant
    • One time constant = all but 37%.
      • e.g. Discharging to 37% in one time constant.
      • e.g. Charging to all but 37% (meaning charged to 63%) in one time constant.
    • Calculating a time constant: T = RC
      • On the test, if you forget, pick the answer that is closest to the microfarad value (for all calculate-the-TC questions)
  • Q
    • Half_Power_Bandwidth = Frequency / Q. [B = F/Q]
      • e.g. If Q = 10, and Frequency = 10 MHz, then Bandwidth = 1MHz.
      • e.g. If Q = 95, and Frequency = 1.8 MHz, then Bandwidth = 1.8 / 95 = 0.0189 MHz = 18.9 KHz.
  • Gates
    • The symbol for the AND gate is rounded.
    • The symbol for the OR gate looks like AND with a pointy rounded end.
    • A triangle is a no-op.
    • The symbol for Nxxx is a little circle at the tip of AND / OR / no-op
    • XOR (and XNOR) have a double line at the input side. e.g.
  • Phase-locked Loop = An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator.
  • If no antenna reference is specified for gain, assume a dipole. (Otherwise, EIRP = Effective Isotropic Radiated Power.)
  • ERP:
    • Add up the dB gain and loss for total dB. Call that TDB.
    • TPO = Transmitter Power Output
    • ERP = InverseLog(TDB/10) * TPO
    • On a TI-36X Pro Calculator, Double-tap [ex 10x] for InverseLog
      • Double-tap “ex 10x”
      • Open paren, TDB / 10, close paren
      • x TPO
    • e.g.
      • If watts is 50 and gain is - 4 dB - 2 dB -1 dB + 6 dB = -1 dB
      • press InverseLog (-1 / 10) * 50
      • press Enter
  • On XY RLC charts, Resistance is to the right; inductance is up; capacitance is down. Pure L or C is way up/down; mixed is near mid-line.
  • A sawtooth wave is made up of a sine wave plus all its harmonics. A square wave is made up of a sine wave plus its odd harmonics.
  • -174 dBm/Hz = The theoretical noise at the input of a perfect receiver
  • Matches:
    • A delta match feeds at two places, each side of center.
    • A gamma match feeds at the center and off one side (like my Arrow VHF Yagi).
    • A stub match runs feed line and radiator in parallel near the feed point
  • P-type uses holes; n-type uses electrons. P = positive, so it has holes (which are anti-electrons); N = Negative, so it has electrons (which are negative).
  • VCC is supplied to MMIC (monolithic microwave integrated circuit) via resistor or a choke on the amplifier output.
  • Spurious emissions must be down 43 dB
  • A hot-carrier (Schottkey) diode is often used as a VHF/UHF detector/mixer.
  • Digital protocols
    • JT65 is designed for moon-bounce
    • PSK31 is narrowest bandwidth. 31 baud and 31 Hz bandwidth. It uses variable-length characters.
    • MFSK16 is FSK with 16 tones; about 300 Hz bandwidth.
  • 120V RMS is 170V peak-to-peak. It is 120V * sqrt(2).
  • An op-amp has high input impedance and low output impedance. (This is what you want. Low-drain input, and low-resistance output.)
  • A marker generator can be used to calibrate a receiver. (Send at a known frequency and see what frequency the receiver thinks it is.)
  • a FET has gate, drain, and source
  • A point-contact diode is a “cat’s whisker” diode.
  • P= IIR
    • This can be derived from P=EI and E=IR
  • Deviation Ratio:
    • Modulation index = DeltaCarrier / Modulation
    • Deviation ratio = MaxDeltaCarrier / MaxModulation
    • Highest allowed modulation index for angle modulation = 1
  • Space stations, Satellites, and Moon:
    • HF - not allowed on 30m (because that’s CW-only)
    • VHF - only allowed on 2 meters
    • UHF - allowed on 70, 23, and 13 cm
    • Mode x/y - uplink before downlink. (Must get TO the satellite before the signal comes FROM the satellite.)
    • Moonbounce at 144.0 to 144.1 (First 100 KHz of 2 meter band). Also at 432.0 to 432.1 (100 KHz, but not at bottom of 70 cm.)
    • Meteor from 10 to 2 meter (28 to 148 MHz).
    • Aurora and mEteor strike happens at the E-layer
  • PSK31 - (Phase Shift Keying, 31-baud) has data rate close to typing speed, and has extremely narrow bandwidth
  • Spread spectrum is permitted above 222 MHz
  • Line-A takes a chunk out of the BOTTOM of the 70 cm band (400 MHz)
    • (“A” is the beginning of the alphabet; Line-A loses the beginning of the band; 400 MHz is the only band in the answers with multiple, close answers.)
  • dB = 10 Log (x/y)
    • Log is base 10
    • e.g. 400x increase in power = 10 Log (400/1) = 26 dB
  • A noise blanker briefly switches off the receiver when a broadband spike occurs. (Not “broadband white noise” and not a narrowband spike.)
  • X,Y graphing of RLC:
    • R is to the Right of the vertical axis.
    • L is up
    • C is down
    • Reactance of an inductor is 2pi * FL
    • Reactance of a capacitor is 1/(2pi * FC)
  • Impurity atom that adds holes to a semiconductor = “Acceptor impurity”. (Mnemonic Atom and Acceptor.)
  • Filter types:
    • Jones Filter - a type of crystal lattice filter

Desktop Alerts for SOTA

If you are a SOTA Chaser, you might be familiar with SOTA Goat. One thing which SOTA Goat does nicely is to alert you when someone has been spotted.

If you want a similar notification on your Windows PC, try KU6J’s SOTA Spot Monitor. It will notify you whenever a SOTA activator gets spotted.

Reasons to Learn CW

CW Brings Certain Advantages to SOTA

You can be a fine SOTA operator using voice modes and you can achieve Mountain Goat or Shack Sloth status using SSB or FM. Shucks, you could succeed using RTTY or JT65 if you were determined, but SOTA has some powerful motivators for learning CW.


You can work CW-only activators.

As a chaser, you have all the equipment in your shack at your disposal. The activators have only what they carry. Many activators do not carry a microphone. (Some activators entire go-kit weighs less than 2 pounds!) You aren’t going to work these activators on SSB.

You can work some of them using your computer to recognize/send CW. (CW is just a digital mode which can be digitized by the operator.) Some decoders are pretty good, but when the activator’s signal is too weak for software decoding, you’ll miss out. Signal strength can be an issue, particularly for DX, but some lightweight trail radios send at about 3 watts.

If you’re working toward your Shack Sloth award, you’ll want to be able to work both CW and SSB activations, in order to get your award faster.

Activators and Spotting

One of the coolest pieces of software on Earth is RBNGate. RBNGate is available solely to CW operators. RBNGate will hear you calling CQ and it will post a spot to SOTAWatch on your behalf.

As a reminder, you do not have to be spotted in order to activate a summit. All you have to do to earn your points is to work 4 hams who are not on the hill with you. However, you can get your contacts easier and have the fun of working the pile-up if you get spotted.

RBNGate joins two other mavelous pieces of software – RBN and SOTAWatch. RBN (Reverse Beacon Network) is out there, day in and day out, spotting CW CQs. SOTA chasers are posting spots for SOTA activators to SOTAWatch. SOTA activators post alerts, stating when they intend to activate, to SOTAWatch. What RBNGate does is to take RBN spots, match them up with SOTA alerts, and when they match, it posts a spot to SOTAWatch.

What this means is that all you have to do once you are set up on a summit is to start calling CQ via CW, and about a minute later you have a pile-up.

There are other ways to get spotted.

But with RBNGate, you just sit down, start calling CQ using CW, and you get spotted.

Very cool.


I love my KX3. The Yaesu FT-817 has many fans. KD1JV’s Mountain Topper (a.k.a. Mountain Top Radio or MTR) series of radios are absolute brilliance. Roughly the size of an Altoid tin (some models are double-size), weighing approximately 1/4 pound, runnable from a single 9-volt battery, they are the paragon of what you want to carry when you’re hiking up the side of a mountain. (i.e. Almost nothing.)

If configured correctly, and your default frequency is free, all you do is plug in your battery, paddle, antenna and earbuds and start calling. Volume level is automatic. Most models don’t even have a power switch. Just plug and call.

Some hams adapt their MTR with a built-in touch paddle, for one less thing to carry and one less thing to plug in.

It only supports CW.

Shortly after I started activating, I bought one of these and put it on a shelf at eye level in my shack, to motivate me to practice CW.

LNR Precision Mountain Topper Radio

The Usual

As CW fans will tell you, CW gets through when voice can’t:

  • When the signal is faint, CW is more likely to get through.
  • When you’re operating next to a mountain-top cell tower and QRM is at S8, CW is more likely to get through.
  • CW doesn’t have a foreign accent you can’t understand.
  • When there’s an SSB contest and the voice frequencies are full, you can move down to CW and find a space to operate.

Crusty old CW operators from back when CW was required in order to get your license sometimes complain that the no-code license spoiled ham radio. SOTA is an example of how the no-code license works well. You get on the air with SSB; you are active with SSB; then you notice advantages of learning CW. Instead of learning it to get your ticket and forgetting it, you learn it because you want to, and you keep using it because it brings you benefits you want.

CW isn’t necessary for SOTA. There are many successful activators and chasers who don’t use it. There are Mountain Goats who got there without a single CW QSO. But CW brings some mighty fine advantages.

Disclaimer: I am not a CW hotshot. I can manage a slow exchange of call signs and RST from a summit… most of the time.

See you on the summits! 73 DE K4KPK / Kevin

Where can I find out more?

  • Official site: http://sotadata.org.uk/
  • Mailing list: https://groups.yahoo.com/groups/summits
  • K4KPK’s site: http://k4kpk.com/content/sota-menu
  • Email me (K4KPK). My email address is available via http://www.qrz.com/db/K4KPK.


K4KPK, Kevin Kleinfelter is Georgia’s first SOTA Mountain Goat. His first QSO (ever) was on a backpacking trip to a 5300’ summit. He has completed more than 140 activations.

This story is Copyright 2015 Kevin P. Kleinfelter. A non-exclusive right to redistribute in electronic or printed form is granted to amateur radio clubs operating in the metro Atlanta area. All other rights reserved.

How to Read a Repeater Listing

I do most of my operating on 20 and 40 meters. I have an HT that I use occasionally for simplex and for APRS. Whenever I try to use it on a repeater, I have to remember how to read a repeater listing.

Here’s a sample repeater listing:

Location Call Freq Offset PL
Ellijay W4HHH 145.170 - 100.0
Dalton N4BZJ 147.135 + 141.3
  • Frequency: The frequency the repeater transmits on.
  • Offset: The repeater listens for your HT a standard offset above/below its transmit frequency. For 2 meters, the offset is 600 kHz.
  • PL: Sometimes called CTCSS. Your HT must transmit this sub-audible tone continuously, while you transmit, in order to open the repeater squelch. It “unlocks” the repeater.

As a rule, if the output frequency (transmit) of the repeater is below 147 mHz, then the input frequency (listening) is 600 kilohertz lower. This is referred to as a negative offset. If the output is 147 Mhz or above, then the input is 600 kilohertz above. This is referred to as a positive offset. Most HTs handle this automatically, using the rule below. The only time you have to mess with this directly is when someone has an oddball repeater. Of the 255 repeaters near me, 9 of them do not follow the convention.

Announce your presence with: “This is K4xxx listening on 146.84” (using your call sign and the repeater frequency). If I were looking for SOTA contacts I might say, “This is K4KPK on the 146.84 repeater. I’m operating from the top of Mount Whatever. Is there anyone who could meet me for a simplex contact?”

W4T Beginner Summits

These are summits I recommend for beginners (or just when you want a low-effort activation) in Tennessee.

W4G Beginner Summits

These are summits I recommend for beginners (or just when you want a low-effort activation) in Georgia.

W4C/WM-042, Whiteside Mountain

Drive Guide - Whiteside Mtn FROM Yellow Mtn Gap

  • Duration: 0:20, 6 miles
  • Google Maps URL: http://goo.gl/maps/TBNCn
  • Seasonal/Limited Access:
  • Directions:
    • Head out (east) on dirt Ponderock Dr
    • R onto paved Ponderock Dr / Ponderosa / Jodytown Dr and go 1.4
    • R on Yellow Mtn Rd and go 400’
    • R on NC-1144 / Norton Rd and go 2.0
    • R on US-64 W and go 1.4
    • L on Whiteside Mtn Rd and go 1.0
    • Bear L on Deville Dr and go 0.1
    • Parking lot - $2 parking fee
  • Food: None

Drive Guide - Whiteside Mtn FROM Cole Gap

  • Duration: 0:15, 6 miles
  • Google Maps URL: http://goo.gl/maps/azU1v
  • Seasonal/Limited Access:
  • Directions:
    • S/W on Buck Creek Rd (as you exit the trail, turn L on the road) and go 2.2
    • L on US-64 E and go 2.8
    • R on Whiteside Mtn Rd and go 1.0
    • Bear L on Deville Dr and go 0.1
    • Parking lot - $2 parking fee
  • Food: None

Drive Guide - back to Highlands NC (where you briefly get 3G cell)

  • Bear R ond Whiteside Mtn Rd out of the lot and go 1
  • L on US-64 W and go 5.5

Trail Guide

  • Duration:
    • Up via flat route: 1.2 miles, 500’ climb, 0:50 hurrying, but tired.
    • Down via flat route: 0:30 running
  • Navigation
    • Head up the stairs near the sign-board
    • At the top of the stairs, turn L
    • After about 200’, there are some stairs on the R. You can take the stairs for the steep route, or continue on the road for the shallow, longer climb. I took the road both ways.
  • Trailhead altitude: ???
  • Summit altitude: ???
  • GPS tracks/waypoints:
    • Trailhead: 35.08044,-83.14419
    • Summit: 35.0813,-83.138

Summit Guide

  • Hang antenna from tree: Yes
  • Space to guy mast: Yes
  • Cell coverage: VZN fail; AT&T fail; APRS sent but unreliable ACK
  • Unique features: Nice views.

See Also

  • http://www.hikewnc.info/besthikes/nantahala-ranger-district/whiteside-mountain
  • http://www.hikewnc.info/trails/nantahala-ranger-district/whiteside-mountain

W4C Beginner Summits

These are summits I recommend for beginners (or just when you want a low-effort activation) in North Carolina.

Beginner Summits

Getting started is sometimes the hardest part. I’m collecting lists of beginner / low-effort SOTA summits here. Whether you are a tyro or just looking for an easy activation, you’ve come to the right place.

If you’re looking at a summit and wondering whether it is easy, look to see how many times it has been activated. If it has been activated more times than nearby summits with similar points, it is probably easy. If it has been activated once or twice by a crazy man, it may be only marginally do-able!

Note: My definition of a beginner summit is that it should:

  • Be reachable in most weather by a 2WD passenger sedan
  • Have a hike of a 1.5 miles or less on an apparent trail
  • Have no bushwhacking
  • Have no complicating factors on the summit.
  • Be on public land or have documented all-ham permission from the land owner.
  • Have well-documented drive/hike information.
  • Pass the ‘red face’ test – Would you send a first-timer up this hill?
  • Have some characteristic(s) which justify sending a beginner (e.g. particularly easy, something to see, all paved roads to the trailhead, VHF activity nearby, etc.)

This is a list of lists page. Click on any of the links below to find lists of beginner summits by association.