Author Topic: Optimize your HF,Emergency Radio for local coverage  (Read 5898 times)

Offline Carl

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Optimize your HF,Emergency Radio for local coverage
« on: August 14, 2016, 02:44:59 PM »
  I continue to see comments about how far away a person can talk with HF (shortwave radio) and so often bite my lip
as I question "what good is someone 2000 miles away when you need HELP NOW??"  Talking far off can be fun...but is
of little help when you need medical assistance of some other aide. DO something to improve your chances with the
LOCAL/LONG RANGE OPTION of a simple NVIS ANTENNA for 40-60-and 80 meters. NVIS fills the gap between VHF and long
distance HF with the advantage of working over mountains and into valleys for a coverage few communications systems
can even partially handle.

  What is NVIS or Near Vertical Incidence Skywave ? It is easier than you might guess...as it is using an antenna close to the ground
so as to get radio saturation close in for hills and valleys and has a big advantage of being LOWER NOISE on receive . I don't know
why EVERY PREPARED PERSON with radio capability does not have such an important addition for their home or portable station.

Rather than scare or bore you with details,here is a link to a easy read description of NVIS...do the assignment the join discussion and
or ask questions.

http://www.w0ipl.net/ECom/NVIS/nvis.htm

Offline DonC

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #1 on: August 14, 2016, 02:54:34 PM »
The only advantage someone 2000 miles might be able to offer would be to possibly call someone for you (if you can't otherwise do it yourself. And I stress "MIGHT" be able to!

In another post I made, I mentioned I have a few antennas in my "go-box." One of them is an NVIS antenna. I of course got the idea from you awhile back from one of our long conversations. (And again thru practical implementation)!

I certainly don't want to rely on somebody in "FarOut-istan" to relay emergency communications for me. Actually, while writing this reply, it got me thinking. The only thing I'd want somebody far away talking to me during a dire situation would be to relay my final thoughts to my family. In a SHTF situation, that may be your only option. (Definitely not to ragchew).

Offline Carl

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #2 on: August 14, 2016, 03:11:27 PM »
NVIS gives the major advantage of beyond line of sight as in working out of and into valleys ,between mountains and providing a level of signal saturation that no other form of radio can match .
HF ,with NVIS, also does not rely on repeaters or other support as it relies on the user ,a radio, and little else besides someone listening to HF withing 300 or so miles of the hazardous situation.
An NVIS ANTENNA can be made from salvaged wire and when cut to length with a antenna matcher to insure the radio efficiently and safely feeds the antenna for getting the info to where it can
do some good.

I HAVE BEEN THERE! When LIVES depended on passing the location of desperate individuals to rescue personnel and proper design and utilization of an antenna was what lives depended on.
You can't wait to prepare for such events as you ,or your loved ones may depend on your preparations and SKILL.

Offline Sailor

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #3 on: August 15, 2016, 07:34:37 AM »
I use email servers (RMS Express, Winmor) outside of NVIS  range to send emails to those who not have radio skills but still need to be in the loop.  Like my parents when they are in Florida in the winter.  I may be in an ice storm black out here in Indiana but can relay an email to them via a server in Canada or the Catskills mountains for example.   For my first line support guys NVIS is it.

Offline Carl

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #4 on: August 15, 2016, 07:41:35 AM »
I use email servers (RMS Express, Winmor) outside of NVIS  range to send emails to those who not have radio skills but still need to be in the loop.  Like my parents when they are in Florida in the winter.  I may be in an ice storm black out here in Indiana but can relay an email to them via a server in Canada or the Catskills mountains for example.   For my first line support guys NVIS is it.
\
Ham or any other form of radio is not always the best choice,though sometimes the ONLY OPTION..my coms kit includes lasers,Launching flares,survey tape,and even mylar space blankets .
More options as often the ONE you count on will not work.

Offline Sailor

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #5 on: August 15, 2016, 07:59:56 AM »
Those 5mw green lasers make fantastic signals.   Moving them rapidly on large trees, water towers low clouds etc. 

Offline Canadian Prepper

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #6 on: August 15, 2016, 11:23:49 AM »
I would have to agree that it's about having multiple options and capabilities, as you can never predict 100% what might happen to you or your equipment.

I tried out one of my available 80m antennas (a mini dipole based upon mobile hamstick antennas) the other day atop a telescoping tripod, to discover that it worked surprisingly well for some local stations in nearby cities, or well within the distance that would be relevant in a localized or regional emergency. It wasn't the perfect solution, but I found it quick to set up and take down, and later discovered that it would work under rainy weather conditions where my main antenna couldn't tune and transmit. The 80m mini dipole didn't tune well across other bands, but I'm thinking of getting a pair of 10m hamsticks, since the latter would be at both the perfect height on my tripod for long distance DXing, but could also work fine locally when VHF/UHF repeaters aren't operational or busy with other priority traffic.

Carl's suggestions help to get the creative, experimental parts of the mind working that are a fine quality to cultivate before necessity forces us to develop them in haste.

Offline Carl

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #7 on: August 15, 2016, 11:28:59 AM »
Canadian KARMA for experimenting with antennas...makes me feel good to be part of your motivation.

Offline Alan Georges

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #8 on: August 15, 2016, 09:23:29 PM »
I don't know
why EVERY PREPARED PERSON with radio capability does not have such an important addition for their home or portable station.

Thing is, these are some of the cheapest and easiest antennas to get in the air with too.  Dipoles or tuned low random wires, either way, these absolutely nail down regional comms.

Offline Carl

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #9 on: August 16, 2016, 03:49:05 AM »
Thing is, these are some of the cheapest and easiest antennas to get in the air with too.  Dipoles or tuned low random wires, either way, these absolutely nail down regional comms.

Also the best for back-up type situations as a wire can be strung to favor the mission with ease and simplicity. My HOME STATION Primary antenna is made from an extension cord that was salvaged from the curbside garbage years ago...I never leave such bargains to the vultures of scrrap dealers.

Offline Smurf Hunter

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #10 on: August 16, 2016, 09:32:49 AM »
Sunday evening I deployed my W3EDP "zepp" in the back of the house.  The neighbors are vacationing at Disneyland, so I have at least a week without them complaining.

I run the coax from an upstairs room, into my attic, and about 3 feet of the ladderline is inside the attic before it exits a slotted air vent.
The ladder line and long wire slope down from 35 feet to 15 feet in a tree. 
Then it bends almost 90 degrees and the final 20 feet of the long wire tapers down to a 6 foot tall fence post.

For whatever reason, in this configuration it's less noisy than my resonant dipoles.  Since the slope from the attic to the tree is facing due west, I have a curious trans-pacific propagation angle.  Only made one DX QSO to Japan, but heard stations from central Russia and China.  I need to free some time up during the grayline hours, but that's also when my XYL wants to hang out and watch the Olympics on TV.

This was on 15 meters, which was reported as "dead".  20 meters was hopping as typical.


Offline Carl

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #11 on: August 16, 2016, 10:02:11 AM »
The W3EDP is an easy to make and deploy wire antenna that was described and discussed HERE:

http://thesurvivalpodcast.com/forum/index.php?topic=53436.0

Offline Carl

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #12 on: August 17, 2016, 09:25:11 AM »
More information and testing of NVIS antennas.

http://www.tactical-link.com/field_deployed_nvis.htm

Offline Carl

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Re: Optimize your HF,Emergency Radio for local coverage
« Reply #13 on: August 30, 2016, 04:22:22 AM »
I would like to also say that NVIS is IDEAL for TACTICAL and LOW POWER portable use as 25 watts is about all that is needed for reliable NVIS communications and this is acceptable with many battery powered radios with proper NVIS antennas. Also ,for those on the run...NVIS can not be direction found easily as the signals come from above and direction finding of only local ,under 25 miles or so, signals is difficult due to scattering of the NVIS signal. You get good local / regional signal saturation without the need for infrastructure .

QUOTE:

Sobering Thoughts about Vulnerability
Natural disasters can disable almost every component of a communications system.  But terrorist attacks are potentially far worse. Think about the difference.  Natural disasters do not purposely target your systems; your systems just happen to be in the way.  Terrorist attacks, on the other hand, are intentionally crafted by technologically savvy planners to inflict the greatest damage to the most vulnerable components of your systems.

Link:

http://www.9-1-1magazine.com/Irving-RF-NVIS-Lifeline