The audio files below can be used to test terminal unit demodulators. They were created by transmitting a test tape (Quick Brown Fox 100 times) using a TU-170 in Tucson AZ. The files were received and recorded at the KFS SDR. The recordings include noise and fading.
| Description | Audio File |
|---|---|
| Night 40 meters (7.086 MHz). 50 watts into random length wire antenna. Starts with reasonable signal then exhibits severe fading. | websdr_recording_2022-03-15T05_45_16Z_7086.0kHz.wav |
| Afternoon 20 meters (14.086 MHz). 90 watts to inverted L. | websdr_recording_2022-06-14T23_08_37Z_14086.0kHz.wav |
| Simultaneous Mark (2125 Hz) and Space (2295 Hz) to transmit testing for selective fading | MarkSpaceSimultaneous.wav |
| Simultaneous 170 Hz shift mark and space as transmitted on 14.2 MHz and received on the KFS SDR. Transmit power was 15 watts. Time was about 2324Z. AGC was turned off so fading could be observed. There is considerable fading and selective fading | websdr_recording_2022-05-17T23_24_19Z_14200.0kHz.wav |
| Simultaneous 850 Hz shift Mark (2125 Hz) and Space (2975 Hz) to transmit testing for selective fading | 2125-2975.wav |
| Simultaneous 850 Hz shift Mark (1075 Hz) and Space (2975 Hz) to transmit testing for selective fading. These lower frequencies are used because 2975 Hz is filtered out by SSB transmitter. | 1075-1925.wav |
| Websdr recording of simultaneous 1075 Hz and 1925 Hz tones transmited on 14.195 MHz USB at 15 watts and received at the KFS SDR. | websdr_recording_2022-05-31T22_09_09Z_14195.0kHz.wav |
| Continuous Mark tone (2125 Hz) | 2125HzTone.wav |
| ITTY, high quality AFSK audio with no fading or noise! Useful for initial tests of a demodulator. A good demodulator should do well with noise and fading. 170 Hz shift, 2125 Hz mark, 2275 Hz space. | ITTY |
| 850 Hz shift stream. 2 kHz center, 1575 Hz mark, 2425 Hz space, 60 wpm, 45bps. | http://n3crk.ddns.net:8000/850 |
| Random data, 22 ms per bit, created by LTSPICE. Use to generate eye diagram. | Afsk22msPerBit.wav |
| Random data, 22 ms per bit, created by LTSPICE. 60 seconds of audio with space 20.8 dB below mark to simulate selective fading. | spiceaudio220629_2022.wav |
| 30 lines of RY, 35 of each plus TEST DE W6IWI before each line. Transmitted with 4 watts into a 30 foot vertical antenna in Tucson AZ and received at the KFS Web SDR. | 170 Hz shift, 2210 Hz center, 850 Hz shift, 2 kHz center |
| 20 news articles (10 each from 2 days.), 60wpm, 2125 Mark, 2295 Space | http://n3crk.ddns.net:8000/tty |
| Old news articles of interest (Rarely refreshed). 60wpm, 2125 Mark, 2295 Space | http://n3crk.ddns.net:8000/retype |
| TTY Artwork, always in good taste (Rarely refreshed).60wpm, 2125 Mark, 2295 Space | http://n3crk.ddns.net:8000/ttyart |
| 20 news articles (10 each from 2 days.), 60wpm, 1525 Mark, 2425 Space | http://n3crk.ddns.net:8000/850 |
| Quick Brown Fox and RY test with 850 Hz shift, 60 wpm. | RTTY_Test_850.wav |
| Random data with 22 ms per bit generated by this LTSPICE file. Tones are 2125 Hz and 2295 Hz. Used to generate eye diagram. | random170.wav |
| Random data with 22 ms per bit generated by this LTSPICE file. Tones are 1575 Hz and 2425 Hz. Used to generate eye diagram. | random850.wav |