howto:hambasics:b003
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howto:hambasics:b003 [2019/11/26 18:37] – [HF Station] ve7hzf | howto:hambasics:b003 [2020/02/20 19:04] – [Transmitters] va7fi | ||
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- | <box orange | + | |<100% ----- >| |
- | '' | + | | [[home |Ham Basics]] |
- | </box> | + | |
+ | <WRAP round todo center box 60%> | ||
+ | **Under Construction**: VA7FI is editing this section, please do not edit it until this notice is taken down. | ||
+ | </WRAP> | ||
====== Station Assembly, Practice and Safety ====== | ====== Station Assembly, Practice and Safety ====== | ||
+ | |||
+ | ===== Block Diagrams ===== | ||
+ | The next few sections use block diagrams to illustrate the configuration of various pieces of equipment. | ||
+ | |||
+ | {{ youtube> | ||
===== HF Station ===== | ===== HF Station ===== | ||
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* The **transceiver** takes the audio from the microphone and creates a modulated radio signal. | * The **transceiver** takes the audio from the microphone and creates a modulated radio signal. | ||
* The **amplifier** takes the radio signal from the transceiver and amplifies its power to 1 kW or even 1.5 kW. | * The **amplifier** takes the radio signal from the transceiver and amplifies its power to 1 kW or even 1.5 kW. | ||
- | * From there, the signal may contain harmonics that are not desirable so it goes through a **Low Pass Filter**, which passes low frequencies and filters out high ones. | + | * From there, the signal may contain |
* After that, the **SWR Bridge** measures how much of the signal is reflected back toward the radio from the antenna system. | * After that, the **SWR Bridge** measures how much of the signal is reflected back toward the radio from the antenna system. | ||
- | * A trick we use to protect the radio equipment is to add a **Tuner**. | + | * A trick we use to protect the radio equipment is to add a **Tuner**. |
* An **Antenna Switch** is a handy piece of equipment to quickly switch between antennas without having to disconnect and connect coax connectors. | * An **Antenna Switch** is a handy piece of equipment to quickly switch between antennas without having to disconnect and connect coax connectors. | ||
* Because of their size difference, it's usual to have a multiband antenna that will work on 20m, 17m, 15m, 12m, and 10m (and maybe even 6m), and a second antenna for 40m, 80m (and maybe even 160m). | * Because of their size difference, it's usual to have a multiband antenna that will work on 20m, 17m, 15m, 12m, and 10m (and maybe even 6m), and a second antenna for 40m, 80m (and maybe even 160m). | ||
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All that being said, it's possible to go on HF with a transceiver that has an small integrated tuner in it, and a single antenna. | All that being said, it's possible to go on HF with a transceiver that has an small integrated tuner in it, and a single antenna. | ||
+ | ===== Transmitters ===== | ||
+ | <WRAP round info box center 80%> | ||
+ | **Review** the [[wavemodulation |Wave Modulation]] page. You should: | ||
+ | * understand the difference between the // | ||
+ | * understand the difference between //AM// and //FM//. | ||
+ | </ | ||
- | ====== Questions ====== | ||
+ | ==== CW Transmitter ==== | ||
+ | {{ : | ||
+ | |||
+ | * The **master oscillator** generates a stable sine wave signal at the rest frequency. | ||
+ | * The **driver / buffer** is the first stage in the amplification process. | ||
+ | * The **key** is basically an on/off switch used to let the signal through to the amplifier or block it. | ||
+ | * The **power amplifier** is the last stage of amplification before the signal is released to the antenna. | ||
+ | |||
+ | |||
+ | ==== FM Transmitter ==== | ||
+ | {{ : | ||
+ | |||
+ | * The **microphone** picks up the sound waves carried by the air and converts them into a weak electrical signal that becomes the // | ||
+ | * The **speech amplifier** increases the strength of the baseband signal before it can modulate the carrier. | ||
+ | * The **modulator** uses the baseband signal to change the carrier oscillator frequency in the next stage. | ||
+ | * The **oscillator** generates a stable sine wave signal at the rest frequency when no modulation is applied. Its frequency changes linearly when fully modulated with no measurable change in amplitude. | ||
+ | * The **frequency multiplier** increases the frequency of the modulated signal by a factor of 2, 3, or 4. This is so that the oscillator frequency can be lower than the frequency transmitted at the antenna. | ||
+ | * The **amplifier** increases the power of the signal to be transmitted by the antenna. | ||
+ | |||
+ | |||
+ | ==== SSB Transmitter ==== | ||
+ | {{ : | ||
+ | |||
+ | * The **microphone** picks up the sound waves carried by the air and converts them into a weak electrical signal that becomes the // | ||
+ | * The **speech amplifier** increases the strength of the baseband signal before it can modulate the carrier. | ||
+ | * The **RF oscillator** generates a stable sine wave signal at the rest frequency. Note that the oscillator frequency can be much lower than the final transmitted frequency. | ||
+ | * The outputs of the speech amplifier and the RF oscillator are mixed together in the **balanced modulator**. This produces a signal with two side bands, only one of which we want to keep. | ||
+ | * The **filter** only lets one sideband through. | ||
+ | * The **VFO** creates a sine wave frequency that can be varied. | ||
+ | * The **mixer** uses the output from the filter and the VFO to generate a higher frequency signal. | ||
+ | * The **linear amplifier** increases the power of the signal to be transmitted by the antenna. | ||
+ | |||
+ | <WRAP important center round 80%> | ||
+ | Note that a [[wp> | ||
+ | </ | ||
+ | |||
+ | ===== Receivers ===== | ||
+ | |||
+ | ==== FM Receiver ==== | ||
+ | Before we look at individual components, there' | ||
+ | |||
+ | {{ : | ||
+ | |||
+ | * The **RF amplifier** increases the strength of the weak radio signal received by the antenna. | ||
+ | * The **local oscillator** creates pure sine wave that can be tuned by the listener. | ||
+ | * The **mixer** takes in the RF signal and mixes it with the pure sine wave from the local oscillator. | ||
+ | * The **filter** removes unwanted frequency created by the mixer and lets the IF pass through to the next stage. | ||
+ | * The **IF amplifier** increases the strength of the IF signal. | ||
+ | * At this point, the signal' | ||
+ | * The **frequency discriminator** extracts the baseband signal. | ||
+ | * The **audio amplifier** increases the strength of the baseband signal before passing it to the speaker. | ||
+ | |||
+ | |||
+ | |||
+ | ==== SSB/CW Receiver ==== | ||
+ | {{ : | ||
+ | |||
+ | ===== Digital System ===== | ||
+ | {{ : | ||
+ | |||
+ | |||
+ | ===== Regulated Power Supply ===== | ||
+ | {{ : | ||
+ | |||
+ | ====== Questions ====== | ||
+ | * B-003-001-001 -> B-003-003-010 | ||
- | [[sections | + | [[propagation |