Скачать или смотреть 6 Khz VLF band - AM MODULATION - compare original audio to 6Khz AM modulated audio

brief demo showing the LINUX APPs used to create AM modulation at VLF - 6 Khz - directly from the PC sound card - using the AUDIO from an ELECRAFT K3S RADIO RECEIVER to modulate the 6Khz VLF

...and then comparing the 6Khz AM audio to the original audio from the ELECRAFT K3S receive audio that is tuned to a local AM RADIO STATION

the software apps did a very good job of directly creating AM MODULATION on the VLF band using the sound card, which was set at a sample rate of 48 Khz...the comparison between the 6Khz AM audio, and the original K3S Rig audio, seemed about the same quality...no degradation of the audio from the original to the 6Khz AM audio was heard

NOTE: The ELECRAFT K3S has a brickwall LOW PASS FILTER set to 4khz...so that not much above 3.2 khz actually is heard on its AM RECEIVER SETTING...even though it is at max bandwidth(5 Khz AM and using the 6 KHZ CRYSTAL FILTER)...still, only about 3.2 Khz bandwidth gets through..which severely limits the treble voice frequencies that are needed for speech and understanding - the syllables and consonants spoken...etc...