Carrier 42 HQX Manual de usuario descargar pdf (Pagina 16)

Below the menu bar, starting on the left, you have the audio input controls/indicators. Notice

in the example only one audio channel is active (the one showing 0) and it is the selected

audio channel (the radio button is ticked). With background noise or weak(er) signals present

the audio level ideally should be zero (0). Audio level is discussed in detail in Appendix B –

Sound Device Details and, at some point, should be considered required reading.

The right portion houses the spectrum display (waterfall display) and its controls. Across the

spectrum display's top is a marker indicating offset in 100 and 50 hertz increments from the

audio pass band's center point. The red marker indicates where your transmitted tones will

fall. The center frequency of the JT65-HF audio pass band is 1270.46 Hz (or ~1270.5 Hz)

and knowing this you can easily calculate where the actual RF tones will fall. Simply take the

dial QRG, add 1270.5 then add the offset to find the lower absolute edge in RF. Add 200 Hz

to that and you'll have a close figure for the upper bounds. [A JT65a signal is not quite 200 Hz wide,

but, for quick calculations it's close enough. The actual maximal width of JT65a is 174.9605 Hz.]

For example; Frequency = 14076000 Hz, TXDF = 0. Lower RF limit = 14076000 + 1270.5 +

0 = 14,077,270.5 Hz and the upper limit is then 14,077,470.5 Hz. It's important to understand

where your actual RF tones fall in case you're ever operating near a band's edge, or simply to

know what's happening... though it's not (usually) something you will have to think about.

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Carrier 42 HQX Manual de usuario Pagina 16