The tables, charts and cheat-sheets worth keeping close — band plans, codes, dosages, ratios. Browse by category, search for exactly what you need, and add the ones you use to your Digital Binder so they print together.
A list supposedly compiled by a person who survived the Bosnian War.
A list supposedly compiled by a person who survived the Bosnian War.
| Frequency | Tone | Mode | Description |
|---|---|---|---|
| 47.420 | 146.2 | FM | Primary (Nationwide) ARCTONE |
| 47.500 | 146.2 | FM | Secondary (Nationwide) ARC-3 |
Special frequencies licensed to the American Red Cross.
| Factor | Description |
|---|---|
| Match | Does the antenna provide a good impedance match to the feed line / transceiver. If not, then power is reflected back to the transceiver (SWR) and not radiated. This lessens performance as well as possibly damages the transceiver. |
| Gain | How well does the antenna convert the electrical signals into radio waves? Some are much more efficient than others. This is measured in dB of gain (where more is generally better). |
| Direction | And does it radiate in all directions equally or is it directional - both have their advantages in different situations. |
| Radiation Angle | Where does the antenna radiate? Unless doing NVIS, you generally want an antenna to radiate outward toward the horizon. |
The antenna is the single most important piece of equipment when performing radio communications.
| Band | Digital ¼ Wave | Digital ½ Wave | Voice ¼ Wave |
|---|---|---|---|
| GMRS | N/A | N/A | 0' 6.03" |
| 70cm | 0' 6.44" | 1' 0.89" | 0' 6.44" |
| 1.25m | 1' 0.54" | 2' 1.08" | 1' 0.54" |
| MURS | N/A | N/A | 1' 6.54" |
Calculated lengths for improvised wire antennas.
| 40 | 45 | 50 | |
|---|---|---|---|
| 1:16" | I | I | G |
| 1:14" | I | I | I |
| 1:12" | G | G | I |
| 1:10" | P | G | G |
Recommendations for different barrel twist rates on different weights of projectiles.
Where to lubricate an AR-15 — the key friction points that require regular lubrication.
Where to lubricate an AR-15 — the key friction points that require regular lubrication.
| 25 yds | 50 yds | 100 yds | |
|---|---|---|---|
| Bullet Trajectory | -0.7" | +0.8" | +3.1" |
There are a few common methods for sighting in an AR-15 rifle.
A reference list of North American telephone area codes and the regions they cover, organized numerically.
A reference list of North American telephone area codes and the regions they cover, organized numerically.
| Frequency | Mode | Description |
|---|---|---|
| 121.500 | AM | Aircraft Emergency and Distress (VHF Guard) |
| 121.775 | AM | Emergency Locator Transmitter (ELT) Training Beacons |
| 122.200 | AM | Flight Watch Weather |
| 122.750 | AM | Aircraft Air-to-Air |
Common frequencies used in private & commercial aviation.
| Band Name | Frequency Range | Description |
|---|---|---|
| 160 m | 1.800 - 2.000 MHz | Amateur radio band. |
| 80 m or 75 m | 3.525 - 4.000 MHz | Amateur radio band. |
| 60 m | 5.330 - 5.405 MHz | Amateur radio band. |
| 40 m | 7.025 - 7.300 MHz | Amateur radio band. |
Which band reaches how far — pick the band for the distance you need, then the radio. HF for long-haul, VHF/UHF for local.
| Item | Shelf Life<br>(@ 70° F) | Calories |
|---|---|---|
| Beans, Pinto | 10+ years | 1,440 per lb. |
| Beans, Kidney | 10+ years | 1,512 per lb. |
| Beans, Navy | 10+ years | 1,184 per lb. |
| Butter, Canned | 2 years | 220 per oz |
Bulk Food Shelf Life & Calories - a field reference.
| Channel | Frequency | Note |
|---|---|---|
| 1 | 156.625 | Red Dot |
| 2 | 151.955 | Purple Dot |
| 3 | 152.885 | |
| 4 | 152.915 |
Specific frequencies allocated for business communication.
| Channel | Frequency | Note |
|---|---|---|
| 1 | 26.965 | |
| 2 | 26.975 | |
| 3 | 26.985 | |
| 4 | 27.005 | Preppers |
Citizens Band (CB) — the license-free 27 MHz service: 40 channels, AM and SSB. Plus the illegal gap and extra channels some utilize.
The complete run of the Pentagon's congressionally-mandated annual assessment of China's armed forces — every edition from the first in 2000 through 2025, hosted here as PDFs.
The complete run of the Pentagon's congressionally-mandated annual assessment of China's armed forces — every edition from the first in 2000 through 2025, hosted here as PDFs.
The requirements for a conflict to be considered a civil war or revolution as per the book, Resort to Arms
The requirements for a conflict to be considered a civil war or revolution as per the book, Resort to Arms
| Type | Impedance<br>(Ω) | Outer<br>Diameter (in) | Dielectric<br>OD (in) |
|---|---|---|---|
| RG-178B, RG-196A | 50 | 0.072 | 0.034 |
| RG-188A, RG-316 | 50 | 0.102 | 0.060 |
| LMR-100A | 50 | 0.110 | 0.060 |
| **RG-174** | **50** | **0.110** | **0.060** |
Impedance and physical size of common coax cables — outer and dielectric diameter and center-conductor gauge, by type.
| Type | 1 MHz | 10 MHz | 30 MHz |
|---|---|---|---|
| RG-178B, RG-196A | 2.60 | 5.60 | 8.00 |
| RG-188A, RG-316 | 3.10 | 6.00 | 8.00 |
| LMR-100A | 1.00 | 1.50 | 3.90 |
| **RG-174** | **1.90** | **3.30** | **5.10** |
Losses for various cables at various frequencies.
| Type | 1 MHz | 10 MHz | 30 MHz |
|---|---|---|---|
| RG-178B, RG-196A | 1,300 | 640 | |
| RG-188A, RG-316 | 1,200 | 500 | 450 |
| LMR-100A | 1,000 | 350 | 230 |
| **RG-174** | **210** | **160** | **110** |
Power ratings for various coax cables at various frequencies.
There are various connectors that are commonly used in radio:
| Revolution | Timeframe |
|---|---|
| Political Reform | From a few years to many decades. |
| Insurgency / Civil War | Average timeframe of 10 years. |
| Color Revolutions | From a few weeks to a maximum of a few months. |
Color revolutions are a typically non-violent form of coup or revolution taken against a government.
| AWG | mm2 | Ø in | Ø mm |
|---|---|---|---|
| 30 | 0.05 | 0.010 | 0.25 |
| 28 | 0.08 | 0.013 | 0.32 |
| 26 | 0.13 | 0.016 | 0.40 |
| 24 | 0.21 | 0.020 | 0.51 |
60°C Insulation: TW, UF
Morse Code is a method of encoding letters, numbers and symbols into a series of 'dits' (short beeps) and 'dahs' (long beeps).
Morse Code is a method of encoding letters, numbers and symbols into a series of 'dits' (short beeps) and 'dahs' (long beeps).
| Mixture | Result |
|---|---|
| Bleach + Vinegar | Chlorine gas |
| Bleach + Ammonia | Chloramine gas |
| Bleach + Rubbing Alcohol | Chloroform |
| Hydrogen Peroxide + Vinegar | Peracetic / peroxyacetic acid |
Mixing certain common household chemicals can have dangerous results:
| Country | Population 2017 | Population 2025 | Population Change (%) |
|---|---|---|---|
| United States | 316,440,000 | 99,553,100 | -68.5 |
| France | 67,100,000 | 39,114,580 | -41.7 |
| Germany | 80,590,000 | 28,134,920 | -65.1 |
| Israel | 7,710,000 | 3,982,480 | -48.3 |
The website deagel.com once contained concerning projections for the year 2025 that many believed was predicting a massive population drop in countries like the United States.
| dBm | Watts |
|---|---|
| 0 | 0.001 |
| 10 | 0.010 |
| 20 | 0.100 |
| 23 | 0.200 |
Decibels (dB) is a common unit within the world of radio that's used to describe a ratio between two signal levels.
| Digital<br>Mode | Common Frequency<br>/ Modulation Used | Computer<br>Program | Description |
|---|---|---|---|
| APRS | VHF/UHF FM HF SSB | Stands for Automatic Packet Reporting System, and was designed to automatically update position over radio. However, it uses packets for transmission, which are very short bursts of data and can also send text message traffic. | |
| FT8 | HF SSB | WSJT-X | One of the most popular digital modes in amateur radio. But very limited in what data it can send. |
| Ion2G | HF SSB | Used for Automatic Link Establishment (ALE). In this, software finds the ideal band to connect two radios. Very new technology, that is still growing/improving. | |
| JS8 | HF SSB | JS8Call | Based on FT8, improvements were made… |
There are various digital modes that can be used to send data over radio.
Dipole antennas are considered the 'ideal' omnidirectional antenna. See the formulas so you can build your own.
| Carrier | Gateway 1 | Gateway 2 |
|---|---|---|
| Alltel | @alite/message.com | @message.alltel.com |
| AT&T | @txt.att.net | @mms.att.net |
| Bell Canada | @txt.be1J.ca | @txt.bellmobility.ca |
| Boost Mobile | @sms.myboostmobile.com | @myboostmobiJe.com |
E-mail to text gateways can be used to deliver text messages from an e-mail address.
| Magnitude | Earthquake Effects | World-Wide Occurrence |
|---|---|---|
| 2.5 or less | Usually not felt, but can be recorded by seismograph. | Millions per year |
| 2.5 to 4.9 | Often felt, but generally causes no damage. | 50,000+ per year |
| 5.0 to 5.9 | Felt by everyone. At most slight damage to well-designed buildings. Can cause major damage to poorly constructed buildings over small regions. | 350 per year |
| 6.0 to 6.9 | Can cause damage to poorly constructed buildings and other structures in areas up to about 100 kilometers across where people live. | 100-150 per year |
Earthquake magnitude is measured using a logarithmic scale.
| City & State | Station ID | Frequency |
|---|---|---|
| Baltimore, Maryland | WBAL | 1090 kHz |
| Birmingham, Alabama | WJOX | 690 kHz |
| Boston, Massachusetts | WBZ | 1030 kHz |
| Casper, Wyoming | KTWO | 1030 kHz |
This national system is one of the best ways to obtain information during a major emergency.
| Condition | Posture |
|---|---|
| 1 — Routine | Any and all transmissions authorized. Permissive environment. |
| 2 — Essential | Mission-critical & emergency only; emitters off except when in use. The default once it's gotten serious. |
| 3 — Silence | No voice — text / burst only, HF / NVIS ideal, short scheduled windows to limit direction-finding. |
| 4 — Blackout | Everything off, batteries out. Occupation or active enemy collection. |
Match how much you transmit to the threat. Every transmission announces "I am here" — four postures, from routine traffic to full radio blackout.
A working archive of 94 government and laboratory primary sources on the electromagnetic pulse — from the 1940s Los Alamos shock-physics work through the modern EMP Commission and DHS reports.
A working archive of 94 government and laboratory primary sources on the electromagnetic pulse — from the 1940s Los Alamos shock-physics work through the modern EMP Commission and DHS reports.
The end-fed half-wave (EFHW) antenna is a great choice for mobile operation.
| UK: FM Only | EU: AM, FM & SSB |
|---|---|
| 27.60125 - 27.99125 | 26.965 - 27.405 |
European band that's not allowed in the USA as it overlaps with our Citizens Band (CB) and various business/government uses.
The X-code markings search teams spray on buildings — how to read who searched, when, the hazards found and any casualties.
FEMA's annual survey of how American households actually prepare for disasters — every available year, 2017 through 2024, archived here as complete data files, codebooks, summaries and questionnaires you can download.
FEMA's annual survey of how American households actually prepare for disasters — every available year, 2017 through 2024, archived here as complete data files, codebooks, summaries and questionnaires you can download.
| Field | What to pass |
|---|---|
| Status | What's happening around you; are you injured or need help? |
| Location | Where you are now (designator, or landmark + distance/direction). |
| Heading | Where you're going next. |
| Method | How you're getting there — vehicle, on foot. |
When you contact someone, keep it brief and hit these points in order: status, location, heading, method, anything else.
| Method | What it does |
|---|---|
| A filter removes… | Sediment, protozoa (Giardia, Crypto), most bacteria — by physical size. |
| A filter usually misses… | Viruses — too small for a standard filter unless it's rated for them. |
| Purifying (boil / chemical / UV)… | Kills viruses too, but doesn't remove sediment or chemicals. |
| Best practice | Filter to clear it, then purify to kill viruses — the two are a pair. |
The distinction that gets people sick: most filters stop protozoa and bacteria but not viruses. Filtering and purifying are a pair, not a choice.
| Species | Green Weight<br>(lbs. / Cord) | Dry Weight<br>(lbs. / Cord) | Heat per Cord<br>(Million BTUs) |
|---|---|---|---|
| Apple | 4,850 | 3,888 | 27.0 |
| Ash, Green | 4,184 | 2,880 | 20.0 |
| Ash, White | 3,952 | 3,472 | 24.2 |
| Birch | 4,312 | 2,992 | 20.8 |
Heat value of firewood by species — green vs. dry weight, million BTU per cord, and BTU per pound.
To maximize shelf life, foods must be stored properly.
To maximize shelf life, foods must be stored properly.
| 1 Person | 4 People | 7 People | |
|---|---|---|---|
| Calories per Day: | 1,200 | 4,800 | 8,400 |
| Calories per Week: | 8,400 | 33,600 | 58,800 |
| Calories per Month: | 36,500 | 146,000 | 255,500 |
| Calories per Year: | 438,000 | 1,752,000 | 3,066,000 |
General food storage guidelines for calories per person.
Radio is characterized by the 'frequency' and 'modulation' of the transmission. Learn what these are.
| Use | Frequency | Notes |
|---|---|---|
| NOAA Weather | 162.400–162.550 MHz | Continuous forecasts & alerts (receive only). |
| 2m Nat'l Simplex Calling | 146.520 MHz | The VHF simplex "calling" channel. |
| CB Ch9 | 27.065 MHz | CB Radio emergency frequency. |
| HF Nat'l Emergency (voice) | 7.232 / 14.280 MHz | Common HF emergency-comms voice. |
A short list worth memorizing or keeping on a card — NOAA weather, the national simplex calling channel, and common HF emergency voice frequencies. Mostly for listening.
| Channel | Frequency | FRS Max Power | GMRS Max Power |
|---|---|---|---|
| 1 | 462.562.5 | 2W | 5W |
| 2 | 462.587.5 | 2W | 5W |
| 3 | 462.612.5 | 2W | 5W |
| 4 | 462.637.5 | 2W | 5W |
FRS and GMRS family-radio channels — the shared channel plan with FRS vs. GMRS power limits and the repeater channels.
| Vegetable | Calories<br>per Cup | Calories<br>per lb. | Calories<br>per 100 sq ft |
|---|---|---|---|
| Wheat | 651 | 1500 | 75,000 |
| Potatoes | 116 | 344 | 20,640 |
| Onions | 64 | 168 | 15,456 |
| Oats | 300 | 1500 | 15,000 |
The calories per cup, lb. and per 100 sq ft of garden space.
| Net | Day | Time | Frequency |
|---|---|---|---|
| North America | Thur. | 1900-1930 | 7.107 |
| North America | Thur. | 1930-2000 | 7.107 |
| North America | Thur. | 2000-2030 | 7.077 |
| North America | Thur. | 2030-2100 | 7.190 |
US and international weekly prepper communication nets.
| Harmonic | 160m | 80m | 60m |
|---|---|---|---|
| Primary | 1.90 | 3.76 | 5.37 |
| 2nd | 3.80 | 7.53 | 10.7 |
| 3rd | 5.70 | 11.3 | 16.1 |
| 4th | 7.60 | 15.1 | 21.5 |
Harmonics are simply multiples of a frequency.
| License | Data | Voice | Voice Mode |
|---|---|---|---|
| Technician | 28.000 - 28.300 | 28.300 - 28.500 | USB |
| General | 28.000 - 28.300 | 28.300 - 29.700 | USB |
| Advanced | 28.000 - 28.300 | 28.300 - 29.700 | USB |
| Extra | 28.000 - 28.300 | 28.300 - 29.700 | USB |
Worldwide long-distance and local communication, but is heavily dependent on solar activity and daytime ionospheric propagation.
| Data | Voice | Voice Mode |
|---|---|---|
| 24.890 - 24.930 | 24.930 - 24.990 | USB |
A contest-free "gentleman's band" that relies on solar activity for daytime long-distance communication.
| License | Data | Voice | Voice Mode |
|---|---|---|---|
| Technician | 21.025 - 21.200* | N/A | N/A |
| General | 21.025 - 21.200 | 21.275 - 21.450 | USB |
| Advanced | 21.025 - 21.200 | 21.225 - 21.450 | USB |
| Extra | 21.000 - 21.200 | 21.200 - 21.450 | USB |
A popular daytime band for long-distance communication that thrives during high solar activity.
| Data | Voice | Voice Mode |
|---|---|---|
| 1.800 - 1.843 | 1.843 - 2.000 | LSB |
The true wordwide band, but only at night.
| Data | Voice | Voice Mode |
|---|---|---|
| 18.068 - 18.110 | 18.110 - 18.168 | USB |
A contest-free WARC band that offers quiet, long-distance daytime propagation ideal for casual voice, CW, and digital conversations
| License | Data | Voice | Voice Mode |
|---|---|---|---|
| General | 14.025 - 14.150 | 14.225 - 14.350 | USB |
| Advanced | 14.025 - 14.150 | 14.175 - 14.350 | USB |
| Extra | 14.000 - 14.150 | 14.150 - 14.350 | USB |
The most popular high-frequency (HF) band for daytime international long-distance communication.
| Data | Voice | Voice Mode |
|---|---|---|
| 10.100 - 10.150 | N/A | N/A |
Contest-free, narrow band restricted to CW and digital modes only - no voice.
| License | Data | Voice | Voice Mode |
|---|---|---|---|
| General | 7.025 - 7.125 | 7.175 - 7.300 | LSB |
| Advanced | 7.025 - 7.125 | 7.125 - 7.300 | LSB |
| Extra | 7.000 - 7.125 | 7.125 - 7.300 | LSB |
The standard daytime long-distance band.
| Channel | Bottom Freq. | Center Freq. | Top Freq. |
|---|---|---|---|
| 1 | 5.330.6 | 5.332 | 5.333.4 |
| 2 | 5.346.6 | 5.348 | 5.349.4 |
| 3 | 5.357.1 | 5.358.5 | 5.359.9 |
| 4 | 5.371.6 | 5.373 | 5.374.4 |
A group of 5 channels that are shared with government use.
| License | Data | Voice | Voice Mode |
|---|---|---|---|
| General | 3.525 - 3.600 | 3.800 - 4.000 | LSB |
| Advanced | 3.525 - 3.600 | 3.700 - 4.000 | LSB |
| Extra | 3.500 - 3.600 | 3.600 - 4.000 | LSB |
Regional daytime communication, local evening chats, and medium- to long-distance nighttime communication
| Medication | Past the date? | Roughly how long |
|---|---|---|
| Sealed tablets & capsules (most) | Usually yes | Commonly years; military testing averaged ~5.5 years of extra shelf life, and sealed samples 28–40 years old were often still ≥90% potent |
| Ibuprofen, acetaminophen, most solid OTC pills | Usually yes | Years past the date if sealed and dry |
| Potassium iodide (KI) tablets | Usually yes | Very stable; extends well when sealed |
A quick reference: which medications keep well past their printed expiration date and roughly how long, and which ones you should never rely on past the date — and why.
| Core | AL | Tolerance (%) |
|---|---|---|
| FB-43-101 | 600.00 | 20 |
| FB-43-2401 | 400.00 | 20 |
| FB-73-2401 | 1600.00 | 20 |
| FB-43-4852 | 2500.00 | 20 |
Basic formulas for inductors with toroid cores.
The unclassified U.S. government assessments of Iran's military — the publicly-released DoD annual reports, the DIA's standalone volume, and the recurring missile, nuclear, and Congressional Research Service reports.
The unclassified U.S. government assessments of Iran's military — the publicly-released DoD annual reports, the DIA's standalone volume, and the recurring missile, nuclear, and Congressional Research Service reports.
J-Pole antennas are a type of omnidirectional vertical antenna that is popular for use on VHF/UHF frequencies.
| Data | Voice | Voice Mode |
|---|---|---|
| 156.0 - 174.0 | 156.0 - 174.0 | FM |
International band of frequencies for boats and other vessels.
| Meat | Calories<br>per lb. |
|---|---|
| Alligator | 440 |
| Beef, Ground | 944 |
| Beef, Rib Eye Steak | 1,094 |
| Beef, Roast | 590 |
The calories and yield for different animals.
| Data | Voice | Voice Mode |
|---|---|---|
| 902.0 - 928.0 | N/A | N/A |
Encrypted text communications using a low powered mesh network.
A Morse-code decoding chart — the dot-and-dash pattern for every letter and number, arranged to decode by ear.
| Ch | Frequency | Bandwidth | Name |
|---|---|---|---|
| 1 | 151.820 | 11.25 kHz | Calling |
| 2 | 151.880 | 11.25 kHz | Safety |
| 3 | 151.940 | 11.25 kHz | Emergency |
| 4 | 154.570 | 20 kHz | Blue Dot |
A set of 5 channels that fall under public radio - no license required.
The U.S. government's unclassified assessments of North Korea's military — the DoD's 2012–2017 Reports to Congress, the DIA's standalone volume, and the recurring missile and Congressional Research Service reports.
The U.S. government's unclassified assessments of North Korea's military — the DoD's 2012–2017 Reports to Congress, the DIA's standalone volume, and the recurring missile and Congressional Research Service reports.
What radiation does to the human body and how to protect against it.
Near-Vertical Incident Skywave (NVIS) is a unique propagation used with high-frequency (HF) modes to transmit to the distances that normal HF propagation won't allow (too far for groundwave,
Near-Vertical Incident Skywave (NVIS) is a unique propagation used with high-frequency (HF) modes to transmit to the distances that normal HF propagation won't allow (too far for groundwave,
| Food Type | 1 Quart | 1 Gallon | 5 Gallon |
|---|---|---|---|
| Beans, lentils, split peas | 125-150cc | 500-600cc | 2500-3000cc |
| Rice | 100cc | 400cc | 2000cc |
| Flour | 100cc | 400cc | 2000cc |
| Instant mixes and powders | 100cc | 400cc | 2000cc |
Oxygen absorbers may only be used with dry foods (10% moisture content or less).
To minimize miscommunication, it's common to use phonetic words instead of saying individual letters over radio.
To minimize miscommunication, it's common to use phonetic words instead of saying individual letters over radio.
| Code | Description |
|---|---|
| 10-1 | Unable Copy - Change Location |
| 10-2 | Signal Good |
| 10-3 | Stop Transmitting |
| 10-4 | Acknowledgment (OK) |
Police commonly use what are known as 10-codes to quickly describe various events.
| Word | Means |
|---|---|
| Over | Done with this statement — your turn. |
| Out | Done transmitting (no reply expected). |
| Roger | I understand / received. |
| Copy | I wrote that down. |
The handful of standard words that keep a radio exchange clean and unambiguous — when you're finished, when you want a repeat, when you'll comply.
The ground-plane vertical — a quarter-wave whip with sloped radials for mounting up high, with element-length formulas.
The quarter-wave vertical — the simplest resonant antenna: how to size the element, and why it needs radials.
| Term | Meaning |
|---|---|
| 73 | Best regards & goodbye |
| CQ | Is anyone there? |
| QRB | How far away are you? |
| QRG | What is my exact frequency? |
The meaning of various terms, acronyms and expressions commonly used in radio, especially amateur radio.
Like with most conversations, there is etiquette that should be observed when using radio.
Like with most conversations, there is etiquette that should be observed when using radio.
There are a few fundamental terms about radio that must be understood.
There are a few fundamental terms about radio that must be understood.
| Band | Frequencies | Offset |
|---|---|---|
| 10m | All | - 0.1 MHz |
| 6m | All | - 0.5 MHz |
| 2m | Below 147.00 MHz | - 0.6 MHz |
| 2m | Above 147.00 MHz | + 0.6 MHz |
Repeaters take in a message and 'repeat' it back out. Here are the common requirements for repeaters by band.
Capacitors and inductors naturally oscillate at a set frequency, and this interaction also generates an impedance (similar electrical effect to a resistor).
There are only four rules of gun safety:
There are only four rules of gun safety:
The authoritative unclassified U.S. government assessments of Russian military power — the DIA's standalone volume plus the recurring missile-threat and Congressional Research Service reports.
The authoritative unclassified U.S. government assessments of Russian military power — the DIA's standalone volume plus the recurring missile-threat and Congressional Research Service reports.
Meat can be preserved for long-term storage by using salt.
Meat can be preserved for long-term storage by using salt.
Within the military, SALUTE reports are the most common way to provide information like scout reports, etc.
Within the military, SALUTE reports are the most common way to provide information like scout reports, etc.
Visual signal that uses flags, lights, fires, etc.
| Readability | Meaning |
|---|---|
| 1 | Unreadable |
| 2 | Barely — occasional words |
| 3 | Readable with difficulty |
| 4 | Readable, almost no trouble |
Two numbers that tell the other station how well you're getting them: how readable, and how strong. "You're five by nine."
Diameter and length are measured center-to-center of the wire, not overall.
The Slim Jim is a variation of the popular J-Pole antenna. They are popular for mobile use on VHF/UHF frequencies.
| Angle | Multiplier |
|---|---|
| 0 (horizontal) | 1.00 |
| 15 | 0.99 |
| 22 | 0.98 |
| 30 | 0.97 |
Dipole antennas can be erected in non-standard ways to achieve different effects or to fit into smaller spaces.
| Season | Panel tilt |
|---|---|
| Spring / Fall | Set to your latitude (latitude 38° → panels at 38°). |
| Summer | Latitude minus 10–15° (38° → 23–28°). |
| Winter | Latitude plus 10–15° (38° → 48–53°). |
Siting and sizing solar panels — tilt and azimuth by season and latitude, daily-output math, and DC wiring.
The earlier of two disputed speeches attributed to Chi Haotian — 'War Is Approaching Us' — arguing that the era of 'peace and development' is over and that China's only path is modernization under the saber.
The earlier of two disputed speeches attributed to Chi Haotian — 'War Is Approaching Us' — arguing that the era of 'peace and development' is over and that China's only path is modernization under the saber.
A controversial and disturbing speech supposedly from a high-ranking member of the CCP.
A controversial and disturbing speech supposedly from a high-ranking member of the CCP.
On any given frequency, there's always a certain amount of noise present.
On any given frequency, there's always a certain amount of noise present.
Skin gets tight & ashen
Skin gets tight & ashen
When sending frequencies down a conductor, if there is any 'mismatch' in the line or between the line and the antenna, some of those frequencies (or a portion of them) will be reflected back
| Zulu /<br>UTC | Central<br>Daylight<br>(UTC−5) | Central<br>Standard<br>(UTC−6) | Hawaii<br>(UTC−10) |
|---|---|---|---|
| 0000 | 1900 | 1800 | 1400 |
| 0100 | 2000 | 1900 | 1500 |
| 0200 | 2100 | 2000 | 1600 |
| 0300 | 2200 | 2100 | 1700 |
Convert Zulu / UTC to Central and back, plus a handful of world zones — so a net time given in Zulu lands at the right hour wherever you are.
| Standard<br>Tones | Standard<br>Tones | Standard<br>Tones | Standard<br>Tones |
|---|---|---|---|
| 67.0 | 97.4 | 136.5 | 186.2 |
| 71.9 | 100.0 | 141.3 | 192.8 |
| 74.4 | 103.5 | 146.2 | 203.5 |
| 77.0 | 107.2 | 151.4 | 210.7 |
While tones are used to access repeaters, they can also serve purposes for simplex communication as well.
| Tornado<br>Rating | Wind<br>Speed | Damage |
|---|---|---|
| EF-0 | 65-85 mph | "Minor" damage. Shingles blown off or parts of a roof peeled off. Damage to gutters/siding. Branches broken off trees. Shallow rooted trees toppled. |
| EF-1 | 86-110 mph | "Moderate" damage. More significant roof damage. Windows broken, exterior doors damaged or lost. Mobile homes overturned or badly damaged. |
| EF-2 | 111-135 mph | "Considerable" damage. Roofs torn off well-constructed homes. Homes shifted off their foundation. Mobile homes completely destroyed. Large trees snapped or uprooted. Cars can be tossed. |
| EF-3 | 136-165 mph | "Severe" damage. Entire stories of well-constructed homes destroyed. Significant damage to large buildings. Homes with weak foundations can be blown away. Trees begin to lose their bark. |
Tornado and hurricane intensity scales — EF and Saffir-Simpson ratings by wind speed, and the damage each brings.
| Material<br>Code | Color<br>Code | Temp<br>Stability<br>(ppm / °C) | Usage<br>(Wideband) |
|---|---|---|---|
| 0 | Blue/Clear | 0 | 150 kHz - 3 MHz |
| 1 | Blue/Clear | 280 | 150 kHz - 3 MHz |
| 2 | Red/Clear | 95 | 250 kHz - 10 MHz |
| 2B | Red/Clear | 95 | 250 kHz - 10 MHz |
Ferrite and iron-powder toroid core mixes — color codes, frequency ranges and uses (wideband, power, RFI) by material.
Toroid core dimensions by model — outer/inner diameter, height, volume and max power for the common FT and T sizes.
| Data | Voice | Voice Mode |
|---|---|---|
| 1240 - 1300 | 1240 - 1300 | FM |
An amateur radio microwave frequency allocation used for experimental communication, satellite links, and weak-signal contesting.
| Data | Voice | Voice Mode |
|---|---|---|
| 902.0 - 928.0 | 902.0 - 928.0 | FM |
An ultra-high frequency (UHF) radio spectrum allocated to amateur radio on a secondary basis for local communication, experimentation, and digital data.
| Data | Voice | Voice Mode |
|---|---|---|
| 420.0 - 450.0 | 420.0 - 450.0 | FM |
UHF Amateur Radio band that sits very close to the public FRS/GMRS bands.
The US Army developed a process to determine if a plant, berry, etc.
The US Army developed a process to determine if a plant, berry, etc.
| Frequencies |
|---|
| 2300 - 2310 MHz |
| 2390 - 2450 MHz |
| 3300 - 3500 MHz |
| 5650 - 5925 MHz |
In addition to all the bands already outlined, amateur radio license holders (except Novice) are allowed to operate in any mode on any of these frequencies:
| Data | Voice | Voice Mode |
|---|---|---|
| 222.0 - 225.0 | 222.0 - 225.0 | FM |
A very unused band between 2m and 70cm.
| Data | Voice | Voice Mode |
|---|---|---|
| 144.0 - 148.0 | 144.1 - 148.0 | FM |
The most common ham band in use, especially for mobile communications.
| Data | Voice | Voice Mode |
|---|---|---|
| 50.100 - 54.000 | 50.100 - 54.000 | Various |
Called the 'magic band', it normally has characteristics of VHF (like 2M), but during large sunspot activity, world-wide communication is possible.
| Source | How to get it |
|---|---|
| Water heater | 40–50+ gallons. Kill power / gas first, then drain from the bottom valve. |
| Toilet TANK | Clean water (the tank, not the bowl) — if no chemical tablets are in it. |
| Pipes | Open the highest faucet to vent, drain from the lowest. |
| Ice, canned-food liquid | Melt ice; the liquid in canned vegetables is drinkable. |
Dozens of gallons are stored in your home right now — the water heater, the toilet tank, the pipes — if you know where to look and what to avoid.
| Water Volume | 5%-9% Sodium Hypochlorite |
|---|---|
| 1 quart/liter | 2 drops or 0.1ml |
| 1 gallon | 8 drop or 0.5ml |
| 5 gallons | 40 drops or 2.5ml or 0.5 teaspoon |
Making questionable water safe to drink — boiling, iodine, bleach and pool-shock dosing, plus what to do about radioactive particles.
Water itself will not be radioactive in this situation, but removing the radioactive particles requires a specific process.
Water itself will not be radioactive in this situation, but removing the radioactive particles requires a specific process.
Humans need about 1 gallon of water per day per person.
Humans need about 1 gallon of water per day per person.
The rule is simple: if you're not certain it's safe, treat it. The situations that always call for treatment, and how often to rotate what you store.
The rule is simple: if you're not certain it's safe, treat it. The situations that always call for treatment, and how often to rotate what you store.
Yagi antennas are very directional antennas that offer very high gains compared to most other antennas.
