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Ham Radio

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(See also: Software-Defined Radio)

Ham Radio is an old hobby that has origins as far back as the late 1800's. It was formalized as a hobby in the early 20th century. It is an over-regulated piece of shit, but what isn't now a days.

Ham Radio

Testing In The US

Element 2 Technician 35 out of 426 questions from this pool

Frequencies 80m 40m 15m 10m 6m 2m 1.25m 70cm 33cm 23cm

Element 3 General 35 out of 462 questions from this pool

Frequencies 2200m 630m 160m 80m 60m 40m 30m 20m 17m
15m 12m 10m 6m 2m 1.25m 70cm 33cm 23cm

Element 4 Amateur Extra 50 out of 712 questions from this pool

Frequencies 2200m 630m 160m 80m 60m 40m 30m 20m 17m
15m 12m 10m 6m 2m 1.25m 70cm 33cm 23cm

Find Testing Locations In The US

Get Your FCC Registration Number

You will need either an FCC Registration or Social Security number in order to take the exam. It is not necessary to register beforehand with the FCC, but it will speed things along if you bring the paperwork.

FCC License Data Search

For a fee of $15 USD you may take one or all three tests in one sitting at no additional charge. If you fail a test, you may spend an additional $15 USD to retake it. Your license is good for 10 years with a 2 year grace period to retest after expiration. You are no longer required to know Morse code for any of these tests.

FCC Part 97 The US Amateur Rulebook

Maths You Should Know

Ohm's Law

Solve For Watts Amp2 x Ohm Volt2 / Ohm Volt x Amp
Solve For Volts Amp x Ohm √Watt x Ohm Watt / Amp
Solve For Amps Volt / Ohm Watt / Volt √Watt / Ohm
Solve For Ohms Volt2 / Watt Volt / Amp Watt / Amp2

Speed of Light Is a Constant 299,792,458 Meters Per Second

Wavelength is represented in Meters as λ

Frequency is represented in Mega Hertz as f

Speed of Light c (300MM) / Frequency f (MHz) = Wavelength λ (Meters)

This is the basic formula to find full wavelength in meters for a given frequency.

Antennas

Loop Antennas are full wavelength with one element.

c/f=λ Element Length

Dipoles are half wave with two elements.

c/f/2 = λ/2 Element Lengths

Ground Planes must be at least quarter wave with one vertical and four radial elements.

c/f/4 = λ Vertical Element Length

c/f/4 = λ Radial Element Lengths

3 Element Yagi Yagis are directional antennas consisting of a boom with reflector, driven, and director elements.

c/f = λ*.495 = Reflector Element Length

c/f = λ*.125 = Boom Separation Length

c/f = λ*.473 = Driven Element Length

c/f = λ*.125 = Boom Separation Length

c/f = λ*.440 = Director Element Length

Polarization

Ionosphere

Electrical Components

ITU Radio Bands

VLF LF MF HF VHF UHF SHF
3 to 30 kHz 30 to 300 kHz 300 to 3 MHz 3 to 30 MHz 30 to 300 MHz 300 to 3 GHz 3 to 30 GHz

Feedline

RG6 is common and cheap, but higher resistance at 75 Ohms. You should not use this.

RG58 is cheap, 50 Ohms, and perfectly acceptable for HF.

RG8X is slightly more expensive than RG58, but lower loss.

RG213 is double the price of RG58 and RG8X, but lower attenuation at higher frequencies.

RG8U is almost identical to RG213 in price and attenuation, but has lower loss per 100ft.

LMR400 is exceptional at higher frequencies as well as low. If your software radio can do 1GHz-6GHz, this is what you get.

Transceiver Type

Q Code

Lightning Protection

If your antenna is outdoors, you should take precaution to prevent yourself and your gear from becoming dead. Metal antenna mounts should be grounded using 10 gauge insulated solid core copper wire. Your coax should have a lightning arrestor between the antenna and your equipment. The arrestor should be mounted near the lightning rod it's grounded to. To prevent moisture ingress, the arrestor and coax connectors should be placed in a plastic electrical box. If you have a wire dipole antenna, you should use ceramic insulators at both ends and guy rope to tie between two points.