Hello Operators
Many of you have commented about my turn back towards low power communications for EMCOMM and Preparedness. Some have gone as far as to ask “Have you lost your freaking mind Julian?”. Suppose we discuss it.
It certainly is nice to use 100 watts of power in the field. Can you think of any other nice things field operators enjoy? Well a long operating time is perhaps number one on that list. The simple truth is, when we discuss emergency communications or communications for preparedness, our goal is not to work a station on the other side of the planet. For preparedness, our goal is to establish communications with the people who matter to us. These people are often within the same region as we are. From an emcomm perspective, the goal is creating that communications link, outside of the disaster zone. In either case are NOT talking about DX contacts. This means we are trying to establish regional communications through NVIS on 80, 60, 40 meters. Sometimes 160 meters, but that is a subject all on it’s own. Once we have met up, we switch over to other systems like DMR, D-STAR, … for what many call “tactical communications”. I digress.
The point is, we are not trying to work DX for EMCOMM or preparedness. As an experiment I have been connecting to Winlink RMS gateways within 500km of my location. This is usually done with 5 watts, using a low strung horizontal antenna, to stations running VARA HF or ARDOP on 80 meters, or 60 meters. If the gateway is not busy, these connections are strong and reliable. They often can’t even be heard through the noise by a human ear, but are decoded fine. Often I attempt 1 watt connections, just to see how robust these connections really are. 1 watt is definitely less reliable, but 5 watts is solid. 5 watts is also a heck of a lot less power, than 100 watts. So why do we care?
The answer is the dreaded Grid Down scenario. We need to think as much about sustainable power and charging, as we do the methods of communication we use to keep in touch or make those EMCOMM links. If you’re running a 100 watt station using voice modes, your station will consume a heck of a lot more power than a station running more efficiently, and consuming less power. This means we use smaller solar panels, we can use smaller lighter weight batteries, and the amount of weight reserved for portable power, can be given away to more critical demands like food, water, shelter, …
There are an awful lot of us saying we need 100 watts for EMCOMM or preparedness. Most of the time that assumption is based on what someone told us, rather than our own field testing. This is a huge problem in the preparedness community, not so much in EMCOMM, which has a different problem. In the EMCOMM community we are weighed down with bureaucracy and legacy methods of working. Methods which have not adapted to modern problems of disaster relief. Again I digress.
The point here is to get us all thinking about it, validating whether or not what I am saying is true, then getting you to think about (at least in part) lower power communications, with rigs you’ve seen on the channel.
Rigs with:
- Low current consumption
- Have low transmit current overhead
- Can be charged away from mains power
- Don’t require disassembly to charge the battery
- The battery can be charged while inside the enclosure.
- The battery can be topped up while operating
- The battery can be topped in a 2-4 hours max, while inside the radio!
To close, here’s some homework.
I would like you all to do a test with your 100 watt rigs. Assuming you have a good antenna, and low enough noise floor, test your ability to connect familiar stations using your normal QRO power level. Afterwards, test using 20 watts, and try to do exactly the same thing. Finally try the same test again using 5 watts. If your 5 watt and 20 watt test is not “better than expected”, try a different antenna orientation. One which favors the stations you’re testing with. Just make certain that station is within 500 km of your location. You’ll probably find that better antenna configuration for the given task, provides more advantage than simply running more power! The trickle down benefits are actually quite astonishing.
We need to be smarter about our emergency communications. Give this a try, then come back and let me know if my “theory” is correct. Just knw this, (I usually know the answer before I ask 😀) At the very least, you might find there is very little difference between 100 watts and 20 watts. You might also find there is very little difference between 20 watts and 5 watts. What we usually need more power for, is battling DXers and contest stations flooding the bands with noise. To combat this problem, we can use a laser beam for communications. Something which cuts through the QRM, and augments our low power philosophy. In communications our laser beams are slow JS8Call, 500hz VARA HF, 500hz ARDOP, and 500hz filters.
73
Julian oh8stn
https://paypal.me/oh8stn/1USD
