PMRC Digital Education Net
Every Tuesday evening at 1900 (7:00 PM)
Every once in a while we try a "retro" DEN using the first digital mode: CW. Actually, we will use MCW (modulated CW audio tones fed into an FM voice transmitter). This is the same technique used by all FM repeaters to identify themselves in Morse. The transmission is pure FM with a carrier, so the signal RF power does not go ON/OFF like "normal" CW. The modulation is Morse, keyed at some audio pitch. So an ordinary FM radio can detect and produce the keyed audio tones of the Morse signal. Therefore, no BFO is needed (a beat-frequency oscillator is needed for SSB, RTTY, and true CW transmissions).
REMEMBER: your radio must be in FM mode, not in CW !
There have been some questions as to how to set up the CONFIG Settings in FLDIGI for MCW. Ask before the net begins... maybe call me or Ron NY3J (co net control) at 6:45 pm on Tuesday evening.
We will take checkins on this week's DEN using CW (MCW). Set up the transmit speed for say 20 wpm.
Click your mouse at 800 Hz on the waterfall. That is the same audio pitch used by the PMRC repeater CW ID. Listening to CW at 1500 Hz pitch would be annoying for most of us.
We will take checkins with MCW, but deliver any traffic with MFSK 32, centered on 1500 Hz (so be careful to change frequency when we switch to traffic mode). Keep your RxID on at all time, and check the option of search total passband for RXID signals. That is, right click on the RxID button, at top of the FLDIGI screen, and choose "search passband". That way any transmit TXID signal at either 800 Hz or at 1500 Hz will be detected at your FLDIGI sound card, and will switch you to the proper mode.
CW is a mode that many can decode "by ear/brain" so of course, we may have some REAL CW ops join us for this net. You can also set up a code-practice oscillator and try sending CW by a hand key..... if you are brave. Just hold the radio's MIC near the CW practice oscillator's headphones/speaker. The tone may be something other than 800 Hz, but we will hear it and see it on the waterfall. Try to adjust the tone for 800 Hz if that is possible. Well-sent CW (by hand or by keyer) is easily copied by the excellent FLDIGI CW demodulator. I've copied W1AW code practice transmissions at 20 wpm with nearly 100% accuracy.
So CW buffs..... come join us!!
Get that code practice oscillator out of the junk box and set it up.
We will aim to run the CW portion of the net at around 20 word/minute but any speed is acceptable.
Remember since we are using a voice repeater to always leave some time between transmissions (wait for the chime) for any voice priority or emergency traffic to break into the net. PMRC is a Mobile Amateur Radio Club, and priority is for any emergency traffic.