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Demonstrates _Freq51_ and _Specgrm2_, two analysis programs from the Biomedical Ultrasonics Laboratory at the University of Michigan, available for DOS or Linux. The _Spectrum Analyser (Freq51)_ provides power spectrum levels as a function of frequency, configurable for absolute values (e.g., dB re 1 volt) with sound card calibration. _Spectrogram (Specgrm2)_ generates a real-time, full-screen spectrogram (sonagram) with various color options. These programs analyze incoming signals in real time, not stored files, and offer extensive settings for sampling rate, FFT points, and averaging time, making them highly versatile for acoustic analysis. The DOS version of _Freq51_ and _Specgrm2_ can operate under Windows 95, requiring users to configure sound card switches via a text file. The resource also briefly mentions other acoustic analysis software like Gianni Pavan's DOS-based bioacoustic tools, _Gram_ by R.S. Horne for Windows, _SASLab_ (Light and Pro versions), _Cool Edit_, and _GoldWave_, providing a comparative overview of available tools for real-time and file-based spectral analysis and waveform manipulation.

N6GN's higher speed packet page for amateur radio digital networks

An Arduino-based interface provides a remote tuner call command for Icom **IC7700** and **IC7800** transceivers, addressing the lack of a built-in function for external tuners such as the MFJ 998RT. This setup initiates a low-power transmit signal, typically 15 watts, allowing the remote autotuner to perform its matching sequence. The article details the required CI-V line communication and modifications to existing Arduino code, specifically referencing contributions from Jean-Jacques ON7EQ for improved Icom interrogation routines. The system involves a sequence of steps: storing the transceiver's current mode and power, disabling the internal autotuner, activating a control relay to interrupt the amplifier line, switching to RTTY mode at low power, and initiating transmit. The transmit duration is manually controlled by the operator, observing the SWR meter until a low SWR is achieved, then a second button press stops the transmission. A built-in 4-second transmit limit provides a safety measure. After tuning, the routine restores the original mode and power settings, re-enables the internal autotuner, and performs a brief 2-second RTTY transmission for internal tuner adjustment. The circuit diagram includes a Panasonic form 2 relay for amp control and emphasizes critical delays in the Arduino code for stable operation at 9600 baud CI-V communication. Compatibility with logging software like DXLab, N1MM, and N3FJP is noted, with specific interrogation time settings required to avoid conflicts.