Update for 12-11-21 14:30
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@ -29,6 +29,9 @@ signal is changed to encode information. The signal as a result will take up
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space both above and below the carrier, called Upper Side Band (USB) and Lower
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Side Band (LSB).
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AM has a Peak Envelope Power. This is determined by the max power of the
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transmitter, and the Mic gain.
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=== SSB ===
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Bandwidth: 2-3khz (voice); 500-3000hz (digital)
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@ -44,6 +47,9 @@ narrower portion of the signal, it is often used for long distance VHF and UHF
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Standards have formed around SSB, and wether to use USB or LSB on different
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frequencies. If < 10Mhz, LSB. Else if >= 10Mhz, USB.
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SSB has a Peak Envelope Power. This is determined by the max power of the
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transmitter, and the Mic gain.
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=== FM/PM ===
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Bandwidth: 10-15khz (voice); 150khz (broadcast)
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@ -52,4 +58,14 @@ Frequency Modulation (FM) and Phase Modulation (PM) are two similar types of
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modulation where the signal is encoded by changing either the frequency of the
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signal, or the phase of the signal.
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Because FM/PM does not change in amplitude, the power output is fixed.
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Therefore, the PEP is fixed as well.
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== Overmodulation ==
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Over modulation or splattering is when the signal is to heavily modulated,
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making it use to much bandwidth. This is generally negative, and can often be
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fixed by speaking softly, changing mic gain, or moving away from the mic.
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The sound it makes to the reciever is a 'breaking up' sound, where distortion
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occours on voice peaks.
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@ -27,3 +27,35 @@ A shorthand is
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WL = 300 / f
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Where f is in Mhz
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== Frequency to Wavelength ==
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Below are the common wavelength and frequencies
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| Frequency (Mhz) | Wavelength |
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----------------------------------------
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| HF/MF | HF/MF |
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| 1.8 | 160m |
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| 3.5 | 80m |
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| 5 | 60m |
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| 7 | 40m |
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| 10 | 30m |
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| 14 | 20m |
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| 18 | 17m |
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| 21 | 15m |
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| 24 | 12m |
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| 28 | 10m |
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| VHF | VHF |
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| 50 | 6m |
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| 144 | 2m |
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| 222 | 1.25m |
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| UHF | UHF |
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| 440 | 70cm |
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| 902 | 33cm |
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| 1240 | 23cm |
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| 2300 | 13cm |
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