Adam H Image Capable Digital Mode (AHICDM)

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Adam H Image Capable Digital Mode (AHICDM)
Spectrum View NEW.png
Frequencies 440 Hz
Frequency Range 440 Hz - 440 Hz
Mode USB
Modulation Unknown
ACF Unknown
Bandwidth 440 Hz
Location United Kingdom
Short Description AHICDM, an updated version of AHVRDM, transmits ASCII (ITA-5) encoded binary data via the time between transmissions. For example, a silence of 200-300MS equates to a 0 and a silence of 400-500MS equates to a 1. The image shows AHICDM transmitting "hello" over USB. AHICDM relies heavily on the transmitter and receiver having a synched clock capable of ticking per millisecond. Fades with moderate / heavy propagation.
I/Q Raw Recording
Audio Sample

AHICDM, an updated version of AHVRDM, transmits ASCII (ITA-5) encoded binary data via the time between transmissions. For example, a silence of 200-300MS equates to a 0 and a silence of 400-500MS equates to a 1. The image shows AHICDM transmitting "hello" over USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables). AHICDM relies heavily on the transmitter and receiver having a synched clock capable of ticking per millisecond. Fades with moderate / heavy propagation.

The mode was originally invented to be a fast yet stable means of transferring binary data over radio, however, the use of only one frequency means that this mode is best for narrowband communication. It uses a tone of 440HZ and sends a consistent sine wave for 100MS. The data is decoded via the duration of the silence.

Bits per second is most likely averaging at 5bps.

That's all I know.