Comments - TRiPLE RESONANT TUNED High "Q" TX & RX Large Ferrite Rod Antennas for VLF CW operations - LiVE DEMO - QRQcw2024-03-28T12:57:26Zhttp://qrqcwnet.ning.com/profiles/comment/feed?attachedTo=1993813%3ABlogPost%3A138222&xn_auth=noPulse Density Modulation batt…tag:qrqcwnet.ning.com,2023-03-15:1993813:Comment:1384222023-03-15T18:06:36.423ZChuck aa0hwhttp://qrqcwnet.ning.com/profile/chase
<p><span>Pulse Density Modulation battery powered 30Khz CW VLF Transmitter - 1/10th power drain of A1-MODE CW</span></p>
<p><span>using the same RESONANT FERRITE ANTENNA setups</span></p>
<p><span><iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/hMI5lc8IMbc?wmode=opaque" width="560"><span>\</span></iframe>
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<p><span>This Pulse Density Modulated CW MODE is 1/10 the power drain of the normal CW MODE with full duration CW elements, since the PDM-CW…</span></p>
<p><span>Pulse Density Modulation battery powered 30Khz CW VLF Transmitter - 1/10th power drain of A1-MODE CW</span></p>
<p><span>using the same RESONANT FERRITE ANTENNA setups</span></p>
<p><span><iframe width="560" height="315" src="https://www.youtube.com/embed/hMI5lc8IMbc?wmode=opaque" frameborder="0" allowfullscreen="">\</iframe>
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<p><span>This Pulse Density Modulated CW MODE is 1/10 the power drain of the normal CW MODE with full duration CW elements, since the PDM-CW transmitter is only "ON" for just 1ms per every 10ms for the duration of each CW ELEMENT...</span></p>
<p><span>ie for a (30 wpm dit) = 40 ms, typical A1 CW MODE DiT, the PDM-CW transmitter is only on for a TOTAL of only 4ms...</span></p>
<p><span>....four.... 1ms batches of 10 cycles of 30Khz sine wave goes out to be transmitted to a 30Khz tuned FERRITE ROD antenna</span></p>
<p><span>the TRANSMIT PDM-CW encoder uses ZAMGATE, and GSTREAMER</span></p>
<p><span>gSTREAMER provides the pulse train, 10 cycles of 30Khz every 10 milliseconds using this script:</span></p>
<p><span>gst-launch-1.0 -v audiotestsrc wave=ticks tick-interval=10000000 sine-periods-per-tick=30 freq=30000 volume=.9 ! audio/x-raw, channels=1, rate=96000 ! audioconvert ! autoaudiosink</span></p>
<p><span>this pulse train is held back by the ZAMGATE APP until ZAMGATE's sidechain port is KEYED by a CW KEYER's audio output... allowing the 30Khz PDM-CW to go through only for the duration of each CW ELEMENT according to the SPEED of the CW KEYER</span></p>
<p><span>to DECODE the PDM-CW TRIGGER MIDI MONO app is used.... an audio TO midi cw app.. TMM analyzes the PEAKS/ and averages them out and creates a MIDI CW KEYING DATA OUTPUT which then goes over to KEY the MIDI INPUT Port of a CW KEYER CPO by RECRI KEYER</span></p>
<p><span><a href="https://github.com/recri/keyer" target="_blank">https://github.com/recri/keyer</a></span></p>