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Phil encouraged me to go further and invest in a "real" radio - one with dials and knobs. It would mean getting in deeper. As I looked for the right transceiver Phil sent his QST magazine with the 2015 product reviews. Featured was the LNR LD-5 QRP software-defined radio. I ordered one and then had to wait. They had sold out thanks to the great
reviews. It gave me time to work on my Morse code. Mostly I worked on sending and looked for software that would help me decode CW. Norbert Pieper's MRP40 Morse decoder is shareware and allowed a 30 day trial. I could not believe how well it worked. I now could listen to CW without the problem of a missed letter - causing a missed word - causing me to give up. When the LD-5 finally came Phil and I could actually have a CW QSO. As that seemed to work, Phil encouraged me to try a CW Sprint run by NAQCC (North American QRP CW Club). Contests? Really?
Power (watts) = Energy (volts) x current (amperes)
Power (watts) = Energy (volts) x current (amperes)
The new radio was quick to learn to operate but there was a problem. If I tuned my antenna correctly and keyed in CW mode or tried sending PSK-31 signals in SSB or digital mode the radio shut down. When the antenna was not tuned it would work but the power was only 1-2 watts and the SWR (standing wave ratio - between the radio and my antenna) was 9.8:1! The SWR - which is a measure of the match between the impedance of the radio and the antenna should be 1:1. I had no way of measuring the SWR except that reported by the radio. Phil suggested I get the QRP SWR meter from MFJ. When it eventually came it confirmed the SWR reported by the radio and tuning the impedance of the antenna caused the radio to shutdown. Finally, Phil asked how I was driving the radio. I had a DC battery that would put out 12v at 8 amps but I was using a wall wart that would put out 12v DC but it could only deliver 1 amp. Switching to the DC battery made everything work! The radio's software had limited the power when the SWR was very high so it only drew 1 amp or less. As soon as I adjusted the SWR to match the radio, the software allowed the radio to increase its power output and the wall wart could not meet the increased current demand! Solving that problem (Phil solved it) had finally taught me a little electronics.
Contacting foreign stations (chasing Dx): JT-9 digital transmissions
Contacting foreign stations (chasing Dx): JT-9 digital transmissions
One of my PSK-31 QSOs was with Brian W3ATT who I knew from his blog QRPzone.com. I emailed him after the QSO since our 5w to 1.5w connection had been lost to fading propagation. He mentioned JT-9: "And for QRPp, jt9 is a blast.. The software pulls signals from below the noise floor. Unbelievable!"
JT-9 is a computer-based radio communication protocol or "mode" that was designed and implemented in software by Joe Taylor, K1JT, a radio astronomer and the 1993 Nobel Laureate in Physics. His interest in amateur radio began as a teenager and his career in physics coincided with the discovery of the first radio pulsar. Radio astronomy has a strong link to amateur radio. The first radio telescope and the first maps of the intensity of the radio sources from within our galaxy were developed by Grote Reber, W9GFZ, after reading about radio frequency radiation from outside our ionosphere in the press in 1933. Here is a LINK to a PDF of his obituary in Nature. Joe Taylor's Nobel prize was awarded for his discovery of a pulsar in a binary star system. As the pulsar and it's unseen companion star orbit each other their orbital distance decays at a rate that confirmed Einstein's prediction of gravitational waves. An excellent discussion of why and how he developed JT-9 and other low-power long distance communication modes is shown in this video from the ARRL National Convention on its 100 anniversary in 2014: https://youtu.be/0ynije-xwboIn the video Joe Taylor lists signal-to-noise ratios for the major modes of amateur radio. JT-9, by using frequency shift keying of a multi-tone code (8 tones carrying data and 1 carrying a synchronizing tone) that is redundantly sent over about 48 seconds, performs 10-15 dB better than the best aural decoding of CW and 25 dB better than voice (SSB). The coding/decoding software uses Reed-Solomon error correcting codes - as are used in most digital data transmissions and digital media. All of this accounts for the incredible ability of the mode to achieve Dx communication.
So, my new LD-5 allowed me to use this new mode at QRP levels and I began to make connections. I compared PSK-31 with JT-9 on the same day at close to the same time using a website called PSKreporter. This image shows the comparison (the "21 hrs" refers to when the signals had been received which was 21 hrs prior to my downloading the report). My JT-9 signal was getting out there and I logged contacts with France, Germany, The Azores, Poland, and Denmark. I was able to decode (but not contact) calls from Russia, Hungary, and Sweden.
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