Tuesday, August 25, 2015

CW Net Ops - Practice for the Zombie Apocalypse

CW Net Ops - strap on your radio and save the world... or just have some fun

I had my first opportunity to participate in a CW Directed Net this past weekend as part of the  Knightlites Roundtable (3574 KHz CW, Sunday evenings at 21:00 EST) .  I have previously participated in numerous VHF club nets, and in a way this is similar, but as a new CW operator it required far more concentration to follow along than a voice net.  The net operator kept the speeds below 10 wpm for me and I appreciated that.  It's a fantastic way to work on your copy skills since you're exposed to a broad range of operator sending styles, tones, signal strengths and inside jokes that you're trying to decipher. 

There can be a bit of Q-code magic involved

While the Knightlites net wasn't heavy on Q-codes I've listened in to some others that were and I was bewildered at the time.  It helps to have a reference sheet from the ARRL QN Signals for CW Net Use handy.
* For use by Net Control

CW Directed Nets follow a similar structure to VHF/UHF/HF phone nets.  The following is excerpted from the NAQCC CW Nets page It is slightly different on the Knightlites net but most CW nets should follow a similar pattern:
Step 1: Net Control (NCS) calls "QRL? QRL?" to see if the frequency is in use. This is a good opportunity to zero beat NCS' signal.
Step 2: Net Control calls "CQ CQ NAQCC NQN DE N4PLK N4PLK NCS QNI K". That means it's time for stations to send their callsigns for Net Control to copy.
Step 3: LISTEN for other stations first. When you don't hear anyone else trying to check in, then send "DE YOURCALLSIGN". The space is very important. It's a way to listen again to be sure that someone else is not trying to check in at the same time. If NCS hears several callsigns trying to check in simultaneously, (commonly called a "double"), he usually can't hear either station and has to ask "AGN PSE". This is especially troublesome with weak stations and bad conditions.
Step 4: When NCS hears your callsign, he will acknowledge it by repeating it. If he receives multiple callsigns, he will repeat all that he has heard. Example: "R R N6TLU ES N9RLO ES W4HH AS". "AS" means standby. The reason I say standby is that I will return to you LATER for comments. When I acknowledge your check-in the first time, that is NOT the time for you to make comments. If you do, you may be doubling with other stations trying to check in.
Step 5: Wait for NCS to call you again. Example: "N6TLU DE N4PLK KN". KN means NCS is calling you and only you. That doesn't mean it's time for more check-ins. Make some comments, say "73" if you wish, and end with "N4PLK DE KN".
Step 6: NCS will call "QNI K" a few times in between comments and listen for more check-ins. If you have not yet been acknowledged by Net Control, keep trying to call until NCS hears you. Remember: DE YOURCALLSIGN"
NCS will call the entire list of stations individually until everyone has had a chance to make comments, giving more opportunities to QNI in between. Please be patient. If NCS can't pull your entire callsign out of the noise, he will try to get it again. Example: "PLK ?" or "AGN?" or "6 STN?" If anyone in the net happens to hear a station that NCS can't, please relay the station's callsign to NCS. We want to make sure even the weakest station can check in.
One thing noted above was "zero beating" the NCS signal.  It's always a good habit when communicating with a station but I think it's even more important in a net because when multiple stations are off frequency then you're really messing around with your RIT to keep them in your passband as it switches between operators.  You don't want to be one of the stations people are having to chase around.

When communication moves beyond "fun" to "necessary"

Directed Nets in Amateur Radio are practical exercises for emergency communication.  One of the goals of Amateur Radio is to provide emergency communications when needed.  If traditional communication infrastructure is compromised due to natural catastrophe or human activity then Amateur Radio operators can be vital in providing electronic communications for organization of relief efforts.

While VHF/UHF communications are ideal for point to point local signals they can be blocked by by structures, terrain or dense vegetation.  In those occurrences the lower HF bands can be effectively used to communicate both over long distance and to other operators in the local county, with low power and a modest antenna.  

Near Vertical Incidence Skywave (NVIS) antenna -- for local ops

NVIS Propagation

One effective mechanism for communication across a wide area with low power is basically throwing your signal straight up and letting the ionosphere reflect it back down like a a light from above (and the angels sang).  
Due to the nature of this type of propagation the signal overcomes ground obstacles and with the signal to power density of CW it makes a very effective mode of communication for a wide area.  The Knightlites QRP net was comprised of operators from all over Wake County NC and I believe even a couple of neighboring counties.  I could copy nearly everyone clearly on my attic antenna and I'm located in the Southern tip of the county.  Such communication with VHF would likely require elevated beams and more than 5 watts for intelligibility.  All forms of radio have their place but CW's power density makes it ideal to get through in an emergency.

So keep that in mind when the inevitable occurs...

Prepare for the Zombie Apocalypse
So lower your power and raise your expectations
Richard - N4PBQ

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