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# You're telling me a Ham Fisted this Metaphor?

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# Amateur Extra

# Rules and Shit (E1)
- **PRB-1** is an FCC document that basically says that localities can't fuck with ham radio equipment (within reason)
	- your HOA can't legally do anything about your massive fucking Antenna but they're damn well gonna try
## TV (E2B)
- Cable TV uses the same frequency range as the Amateur 70cm band, so you can fit Fast-Scan TV into the same channels
	- what the fuck does this mean (**E2B08**)
- Transmitting on Channel 2 (VHF TV) is illegal for amateurs
- **Upper Sideband (USB)** modulation with a sound card is only used for SSTV
- **NTSC** runs at 525i, 483 of which are visible, the rest is for vsync and other meta stuff
	- so basically 480i with extra metadata

## Modes and Procedures (E2D)
- MSK144 is designed for Meteor Scatter
	- Contact can be made on VHF up to 1300mi using Meteor Scatter
- APRS (Automatic Packet Reporting System) sends packet data, ie locations/text/weather
- WSPR (Weak Signal Propagation Reporter) is for testing propagation
- Hellschreiber is for some sort of Fax Machine?
## Propagation (E3)
- **Trans-equatorial propagation** can be afternoon or evening
	- Afternoon 
		- 4000-5000 miles
		- limited to 60MHz
		- High signal strength, but moderate distortion due to multipath bs
	- Evening
		- Peaks at 7PM-11PM
		- Up to 220MHz, sometimes even 432MHz
		- quenched(tf does that mean?) by moderate to severe geomagnetic disturbances
		- depends on high solar activity
- **Sporadic-E Propagation** 
	- ~~is what happenes to my endocrine system when I'm on a family trip~~
	- is when signals sometimes bounces off the E layer, which gives you less range 
		- usually the bouncing happens higher (in the F layer), which gives you more range
	Happens around solstices, especially summer
## Measuring Stuff (E4A,B)
- **Frequency Counters** depend on the accuracy of the **Time Base**
	- aka a **Reference Frequency**
- **Standing Wave Ratio**
	- checks for impedance mismatch
	- measures ratio of peak to trough in a standing wave(?)
		- how do you get a standing wave here?
	- can be measured by an **Antenna Analyzer**, **Directional Wattmeter**, or **Vector Network Analyzer**
# Receiving Stuff (E4,C,D,E)
- **Intermodulation** happens when you have two signals with different frequencies passing through a "nonlinear system" (what?), which I guess causes constructive? destructive? interference
	- everything is at least a little nonlinear (again what the *fuck* does that mean)
	- seems like the base frequencies and all their harmonics join in on the interference, I think it's like some sort of clusterfuck of a beat frequency?
	- ![Here's the graph of 270 and 275MHz signals getting intermodulated](Pasted%20image%2020260104133540.png)
	- okay so plugging $f\left(k,x\right)=\sin\left(2.7\cdot kx\right)+\sin\left(2.75\cdot kx\right), f\left(1,x\right)+f\left(2,x\right)+f\left(3,x\right)+f\left(4,x\right)+f\left(5,x\right)+f\left(6,x\right)+f\left(7,x\right)$ into desmos looks nothing like this graph so
## Circuit City (E5,6,7)
- Microwave freqs need short connections to reduce phase shift
	- what?
- Emitter Follower/Common Collector Amplifier
	- has the RX and TX signals in phase
	- Has a gain close to 1 (doesn't amplify voltage, but boosts current?)
	- ....I'm not actually sure how this works and I'm too sleep to look it up
- **Op-amp**
	- Voltage amplifier
		- in theory, infinite input impedance, 0 output impedance
- **Parasitic Inductance** is a thing that fucks with Capacitors
	- physically bigger capacitors have more of this, tends to cause issues for RF
- Two types of Semiconductors
	- N-Type is negative since it has extra electrons
	- P-Type is positive since it doesn't have enough electrons

## Digital Signals (E8)
- **Audio Freq Shift Keying (AFSK)** sends beep boops into a transmitter which sends them as AM/FM/SSB/what have you
	- if the beep boops are too loud going into the transmitter, shit goes wrong with the Carrier Frequency (Overmodulation)
	- This does AoE damage to the band and pisses off everyone whose signal you just interfered with
	- tl;dr It's like talking in a room, if you're too loud you'll piss off everyone in the room next to it (okay the metaphor is dogshit but)
	- you also need to turn off Automatic Level Control/reduce gain to prevent distortion
- 8-Bit ADC can quantize signal down to 8 bits
	- I honestly don't know what you expected

## Antennas (E9)
- Two $\frac14\lambda$ vertical antennas can be used for directionality
	- $\frac12\lambda$ apart in phase yields a figure-8 radiation pattern broadsidei to the axis
	- if they're out of phase, it's the same pattern along the axis
	- $\frac14\lambda$ apart in phase $90\degree$ out of phase is a cardioid 
- 160m and 80m Antennas need directivity due to atmospheric noise
	- At low HF frequencies, ligthning and other stuff generates RF interference that travels far (due to ionosphere refraction)
	- tl;dr Antenna gain isn't gonna do shit to fix the SNR wrt atmospheric noise
- An **Isotropic Antenna** is the spherical cow of the radio world
- **Yagi Antennas**
	- ![](Pasted%20image%2020260104130032.png)
	- can use a Beta/Hairpin matching system to change the impedance 
		- involves using a loop (sometimes shaped like a hairpin) across the terminals of the antenna, which makes the coil act as an inductor
		- This improves antenna performance by reducing reflections of RF energy back down the TX line
	- **Pennant Antenna** is a single-turn terminated loop?
		- tf does this look like
		- Creates a cardioid radiation pattern
	- **Folded Dipole Antenna**
		- $\frac12\lambda$ with a wire in parallel connecting both ends
			- how is this different than a pennant
			- it's literally just a $1\lambda$ wire folded in half
			- I can't find a copyright free pic but just imagine the schematic looks goofy
	- **Gamma Matching** is when a you (impedance?) match a coax cable to an antenna by connecting the shielding to the center of the antenna and putting the coax conductor some fraction of the wavelength away
		- if your impedance is less than 50ohms,this should do the trick?
		- I'm gonna be honest I barely understand what impedance is, forget impedance matching
		- anyway Yagi Antennas rarely have 50ohm impedance so like gamma matching is good for those
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# Technician

- nvm I passed this by grinding [hamstudy](https://hamstudy.org)
	- nearly passed the General one too at the same time so uh
- callsign format
  - standard 2x3
    - `K\w\d\w\w\w`
  - vanity 1x3
	- `K\d\*\*\*`