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Update for 12-11-21 14:30

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Tyler Perkins 2021-11-12 14:30:01 -05:00
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16
tech/Modulation.wiki
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@ -29,6 +29,9 @@ signal is changed to encode information. The signal as a result will take up
space both above and below the carrier, called Upper Side Band (USB) and Lower space both above and below the carrier, called Upper Side Band (USB) and Lower
Side Band (LSB). Side Band (LSB).
AM has a Peak Envelope Power. This is determined by the max power of the
transmitter, and the Mic gain.
=== SSB === === SSB ===
Bandwidth: 2-3khz (voice); 500-3000hz (digital) Bandwidth: 2-3khz (voice); 500-3000hz (digital)
@ -44,6 +47,9 @@ narrower portion of the signal, it is often used for long distance VHF and UHF
Standards have formed around SSB, and wether to use USB or LSB on different Standards have formed around SSB, and wether to use USB or LSB on different
frequencies. If < 10Mhz, LSB. Else if >= 10Mhz, USB. frequencies. If < 10Mhz, LSB. Else if >= 10Mhz, USB.
SSB has a Peak Envelope Power. This is determined by the max power of the
transmitter, and the Mic gain.
=== FM/PM === === FM/PM ===
Bandwidth: 10-15khz (voice); 150khz (broadcast) Bandwidth: 10-15khz (voice); 150khz (broadcast)
@ -52,4 +58,14 @@ Frequency Modulation (FM) and Phase Modulation (PM) are two similar types of
modulation where the signal is encoded by changing either the frequency of the modulation where the signal is encoded by changing either the frequency of the
signal, or the phase of the signal. signal, or the phase of the signal.
Because FM/PM does not change in amplitude, the power output is fixed.
Therefore, the PEP is fixed as well.
== Overmodulation ==
Over modulation or splattering is when the signal is to heavily modulated,
making it use to much bandwidth. This is generally negative, and can often be
fixed by speaking softly, changing mic gain, or moving away from the mic.
The sound it makes to the reciever is a 'breaking up' sound, where distortion
occours on voice peaks.

32
tech/frequency_range.wiki
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@ -27,3 +27,35 @@ A shorthand is
WL = 300 / f WL = 300 / f
Where f is in Mhz Where f is in Mhz
== Frequency to Wavelength ==
Below are the common wavelength and frequencies
| Frequency (Mhz) | Wavelength |
----------------------------------------
| HF/MF | HF/MF |
| 1.8 | 160m |
| 3.5 | 80m |
| 5 | 60m |
| 7 | 40m |
| 10 | 30m |
| 14 | 20m |
| 18 | 17m |
| 21 | 15m |
| 24 | 12m |
| 28 | 10m |
| VHF | VHF |
| 50 | 6m |
| 144 | 2m |
| 222 | 1.25m |
| UHF | UHF |
| 440 | 70cm |
| 902 | 33cm |
| 1240 | 23cm |
| 2300 | 13cm |