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General Category => General Radio Discussion => Topic started by: Zane on October 22, 2025, 2037 UTC

Title: Loggings with CUSB in the title
Post by: Zane on October 22, 2025, 2037 UTC

Recently, I've seen loggings where the modulation is listed as CUSB. Not being familiar with this, the closest explanation I can find is Controlled Envelope Single Sideband. In these loggings, it's Controlled Envelope Upper Side Band (CEUSB or CUSB)?  Is this correct?

For those of us with non-SDR, Fansome approved radios I assume there is no real reception difference. Only the SDR folks would be able to identify the narrower side band?

Is there a tradeoff here? More effective power, but maybe less audio dynamic range?

On edit - I see one of Chris' old loggings showing this as carrier + USB. Is there a technical reason to do this? 

Z

Title: Re: Loggings with CUSB in the title
Post by: Shortwave_Listener on October 22, 2025, 2048 UTC

Carrier + USB. Fully decodable in AM on any normal receiver, also decodable in USB. The only way to tell on a regular radio is switch between AM, USB, and LSB. LSB will have no audio but AM and USB will sound fine. The benefit is mostly just a little less power and bandwidth are used. Some older radios designed primarily for sideband can only generate this instead of AM.

Title: Re: Loggings with CUSB in the title
Post by: Zane on October 22, 2025, 2200 UTC

Quote from: Shortwave_Listener on October 22, 2025, 2048 UTC

Carrier + USB. Fully decodable in AM on any normal receiver, also decodable in USB. The only way to tell on a regular radio is switch between AM, USB, and LSB. LSB will have no audio but AM and USB will sound fine. The benefit is mostly just a little less power and bandwidth are used. Some older radios designed primarily for sideband can only generate this instead of AM.

Thanks much for the clear response.

Z