Modulation

[William TassoParticipant]

Hello

As consumers of commercial radio we are accustomed to using LW MW (AM) and VHF (FM).

My question … is there a connection between frequency (frequencies) and modulation or is the terminology simply a convention?

Secondary question: in effect, is Sideband a form of Frequency Modulation?

Thank you.

[petesKeymaster]

Hi,

Shortwave, Mediumwave and Longwave are consumer terms referring to the wavelength. Amateurs refer to wavelengths in specific lengths, such as a wavelength of 40 metres.

There is no direct connection between wavelength and modulation.

Sideband is not a form of frequency modulation. For Foundation, you can assume FM, AM and SSB (single sideband) as separate modulation types.

Pete

[William TassoParticipant]

Thanks Pete

So my follow up question: How does the amateur know which demodulator to use?

— Bill

[petesKeymaster]

Modulation is covered in more detail in Module 3, but the short answer is “the bandplans” – see the sample provided on page 3 of the exam booklet, where you’ll get a feel for what frequencies use what modes. Bandplans are covered in modules 6 and 9.

Pete

[Author]

Posts