Bitcoin donations to: 1CE9UfWJcHBYkWPns7iqBqZgKhd5xfqEaM thanks!
Buy Bitcoins easily by clicking HERE!


Use coupon radiopreppers for 20% off on the above site.Become a Patron!

Author Topic: Setup for post-collapse communication with family?  (Read 21527 times)

gil

  • Administrator
  • Hero Member
  • *****
  • Posts: 2949
  • SMeter: +78/-3
    • View Profile
    • Radio Preppers
Re: Setup for post-collapse communication with family?
« Reply #15 on: September 11, 2012, 03:35:04 PM »
Hello rg,

I don't think you will be gaining much by spending more on a CB radio. The only more expensive ones are the fake "10m" CBs, which you can buy but are illegal. The Galaxy does everything a CB is going to do, and legally... I would suggest getting it, then saving a bit of money for a Ham radio. You can get an awesome HF radio on Ebay for $200. The license isn't hard to get.

Gil.

Frosty

  • Guest
Re: Setup for post-collapse communication with family?
« Reply #16 on: September 11, 2012, 08:19:06 PM »
The pic is gone (edit: NM, see it now).  You were the furthest one out rg?  The others between about 10 o'clock and 2 o'clock from your location and the furthest 26 miles out?  You mentioned $200-$300 (X5?).  I might think about putting most of the $1500 into a tower or mast at your end, and get something like a $300 10/11/12m 50w export rig with a directional beam.  Get a second standard SSB CB and see what kind of distance you're getting before buying all 5 sets, and maybe being disappointed.  Least you've got a decent base to build from, and a mobile, if it doesn't work out.  Assumes you don't live in an apartment or HOA tho.  For SHTF use only, of course.
« Last Edit: September 11, 2012, 08:20:52 PM by Frosty »

gil

  • Administrator
  • Hero Member
  • *****
  • Posts: 2949
  • SMeter: +78/-3
    • View Profile
    • Radio Preppers
Re: Setup for post-collapse communication with family?
« Reply #17 on: September 11, 2012, 09:10:13 PM »
Like Frosty says, spending more on a good antenna makes better sense. Export rigs are illegal (do not suggest it). Using a high gain antenna, you could multiply your output power. Placing the antenna higher will also give you much better results. Also, using horizontally polarized antennas (dipole, Yagi, quad) will cut down the noise compared to verticals.

Gil.

rg

  • Guest
Re: Setup for post-collapse communication with family?
« Reply #18 on: September 11, 2012, 09:39:06 PM »
Like Frosty says, spending more on a good antenna makes better sense. Export rigs are illegal (do not suggest it). Using a high gain antenna, you could multiply your output power. Placing the antenna higher will also give you much better results. Also, using horizontally polarized antennas (dipole, Yagi, quad) will cut down the noise compared to verticals.

Gil.

Ok, i guess there's nothing left than to get a couple units and start DXing. Are export rigs illegal due to the wattage or some other reason? I have no restrictions where i live and plenty of land to set up the antenna (although I will probably mount to the roof and gain the ground height).

gil

  • Administrator
  • Hero Member
  • *****
  • Posts: 2949
  • SMeter: +78/-3
    • View Profile
    • Radio Preppers
Re: Setup for post-collapse communication with family?
« Reply #19 on: September 11, 2012, 10:00:20 PM »
Quote
Are export rigs illegal due to the wattage or some other reason?

Both power and frequency range... As far as I know just having them on the premises is illegal, even if you are not transmitting! Same goes for CB RF amps.

Gil.

White Tiger

  • Hero Member
  • *****
  • Posts: 526
  • SMeter: +11/-0
    • View Profile
Re: Setup for post-collapse communication with family?
« Reply #20 on: September 27, 2012, 03:12:24 PM »
Wow. this whole topic sounds like one WA4STO and I played out a couple of months ago!?

If I had to bet, I would apply "White Tiger's rule of 10k"...that is; "if you're thinking it - there are probably 10,000 people kind-sorta similar to you, thinking the exact same thing..." (...and since there's actually no way to prove my theory - there's also no way to DISprove it - so it must be right)!

Anyway, here's what we came to - I have almost an identical situation listed by rg in the OP. About 4 to 5 families (let's call them "the in-laws) within 20 to 40 miles of each other - but I have an addional problem - the other side (lets call them the Outlaws) of the family consisting of 6 very important people comprising 3 familes, nearly 500 miles away!?

Gil mentioned NVIS - which in my opinion is THE ANSWER. As I understand NVIS (thanks to more than a few conversations with Luck WA4STO) it requires a HF rig and a dipole antenna - that's pretty much it! ...now the dipole has to be erected in a specific manner to make it work (that is: hang the dipole about 7' to 8' off the ground) which severely limits what most HF hams LOVE about HF (i.e., distant signals/contacts), but it isn't something that permanently hinders you, just something that you can convert to if you ONLY ever want to have one antenna system.

Here's a QSL.net blog post/article on NVIS I found very helpful: NVIS: Near Vertical Incidence Skywave

Now, remember, I'm new at this and as of this moment - UNlicensed - but from what I have read, the military really developed the use of NVIS while operating/coordinating in mountainous locations - when line-of-site gets blocked by...well...mountains. By bouncing the radio signal from the ground - nearly straight up - the beam is then reflected/refracted back down towards the antenna - but in circlar radiation pattern - and because of the steep reflected angles - the covered area is now a giant circle between 0 to 300 miles around the antenna- filling in the gaps that line-o-sight can't get around (see, you're not hindered by line of sight - if you're coming down from above)!

As I see it -here are the pro's & con's we came to in our discussions - and further reading (and the linked article) seem to confirm:

Positives:

1) Simple, lowest cost HF antenna system can be employed - AND it does not require a tuner.
2) Relative ease in setting up the antenna - as it only has to be as high as 7' or 8' off the ground (throw that dipole over a tree branch)!
3) Short pathways mean less path loss (D layer signal absorption)
4) Clearer signals as short path = less interference

The drawbacks:

1) It apparently can only be "worked" from 2 mHz to 10 mHz - requiring HF - and if you're using SSB-voice that = a little more expensive rig(s).
2) If you do NOT have BOTH transmitting and receiving antenna's of the group set up for NVIS - it won't work.
3) If you do have the antenna's set up the same - you won't be DXing. Because you lose the flexibility of those shortwaves by limiting their effective range to only 30 to 600 miles (although, it is easily RE-configurable as it only requires a change to you simple dipole configuration.
4) You will have to experiment which frequencies work best for your group...but it sounds like for what I want to use it for - it is the most cost effective...but that may be because at least one person in each family (and their are 4 families) in my "comm group" has committed to becoming licensed...
5) Round the clock reliability will be effected by time of day (daylight vs night time propagation), meaning a couple of different frequencies will have to be used depeneding on when you will be using it to communicate.

I've never done NVIS - so I don't know any more than what I have read and discussed with a REAL radio operator - but the fact remains it is used today for the very purposes outlined by the OP - that not a lot of people use this system - has a certain OPSEC allure to it! .

Now that is if you're budget limits you to using ONE system for ALL types of communication...but if your budget allowed for more - why not have each member of your communication group use Hanheld 2 to 6 meter devices/CB's in vehicles - and HF/NVIS in your ham shack? Seems like you'd have all the bases covered for as little cost as possible!?

OK more experienced hams - please tell me where I'm wrong or have oversimplified! Because - 1) I don't want my ignorance misleading anyone 2) I plan to have an emergency "go to" antenna to use NVIS during/after stuff hitting the fan - and I have almost convinced two of the 3 other families in my comm group to buy HF rigs utilizing dipole antennas!!
« Last Edit: September 27, 2012, 03:19:27 PM by White Tiger »
If you're looking for me, you're probably looking in the wrong place.

gil

  • Administrator
  • Hero Member
  • *****
  • Posts: 2949
  • SMeter: +78/-3
    • View Profile
    • Radio Preppers
Re: Setup for post-collapse communication with family?
« Reply #21 on: September 27, 2012, 03:57:15 PM »
Pretty well explained Tim. NVIS definitely for 500miles. Anything below 60miles, a cheap VHF mobile like the Yaesu FT-2900R (75W) and a Yagi-Uda antenna will do it. You're looking at $250 top, for both items. The issue here is also to get someone in each household to get a license. Technician, they might get, easy enough; General, for someone who is not into radio is a bit more of a hassle..

As to the dipole for NVIS, 7-8 ft. in my opinion is a bit low. You want to reduce ground losses as much as possible. But maybe I'm wrong. I know 8ft. works fine, the difference might not be worth the effort. It doesn't take much power to make contact. I had a short 625 miles QSO yesterday on 1W using CW!

You can find all-mode 2m radios on Ebay for $200. 2m SSB can get you pretty far, 200 miles...
I just got this one for $305:

Not sure if I'll ever use it, I'm not a phone guy, but you never know..
I do like to listen to people make fools of themselves on VHF FM though  ::)

There is also ground wave propagation, more on 80 and 160m, but that requires a very long dipole!

Gil.

White Tiger

  • Hero Member
  • *****
  • Posts: 526
  • SMeter: +11/-0
    • View Profile
Re: Setup for post-collapse communication with family?
« Reply #22 on: September 27, 2012, 04:26:37 PM »
Nice rig!

for about the same money you could get yerself a Ten Tec....don't you hear those (HF) voices calling?
If you're looking for me, you're probably looking in the wrong place.

gil

  • Administrator
  • Hero Member
  • *****
  • Posts: 2949
  • SMeter: +78/-3
    • View Profile
    • Radio Preppers
Re: Setup for post-collapse communication with family?
« Reply #23 on: September 27, 2012, 04:33:23 PM »
I have my K2 for that! Though I can't reply, since I haven't built the SSB board yet...

Gil.

WA4STO

  • Guest
Multi-mode 2m rigs
« Reply #24 on: September 27, 2012, 05:27:13 PM »
Aw, Gil, that's a BEAUTIFUL rig!

I used to use the IC271a to work the  satellites.  Back then, they were mostly CW and SSB birds, but a few (Fuji-OSCAR 20 comes to mind) had digital BBSs on board; I've got a QSL from HS1JC in Bangkok that was for a packet BBS QSO on FO20.

Today, I'd be using that IC271 to copy the telemetry from the International Space Station's amateur radio transmissions.

Frosty

  • Guest
Re: Setup for post-collapse communication with family?
« Reply #25 on: September 27, 2012, 08:05:13 PM »
Anything below 60miles, a cheap VHF mobile like the Yaesu FT-2900R (75W) and a Yagi-Uda antenna will do it. You're looking at $250 top, for both items.

60 miles on VHF? Not without a repeater.   VHF won't bounce off the ionosphere, LOS between the antennas X 1.4 is the general rule for distance I think. 

RadioRay

  • Administrator
  • Hero Member
  • *****
  • Posts: 790
  • SMeter: +45/-2
    • View Profile
Re: Setup for post-collapse communication with family?
« Reply #26 on: September 27, 2012, 09:02:08 PM »
NVIS for 'area communications - roughly 0 - 350 miles out, that's a BIG pancake.  I found the best frequencies of course change with season, time of day and of course - solar flux.  However, the general rule is 'as high as you can go and still makethe contact, because the lower that you go, the MORE atmopsheric absorption that you have, higher noise & etc...

3.5 - 7 MHz has been most effective for me, starting with 3.5 int e mornings, until it would fade, then using 7 MHz until it would go 'long'.  Naturally the 5 MHz voice allocations are excellent for NVIS, but ham 5 MHz is channelized, so not a lot of wiggle room.

OTOH during the last year and Buddy & I were rusing digital in the 3.5 MHz band and had almst 24/7 converage, with him being between 200-275 miles out, depending upon his location & antenna.  The dipole was the best of the lot.

>>> Antennas:  I've worked a LOT of NVIS down throght he years, and while ground losses DO increase -as Gil pointed-out - as the antenna comes closer to dirt, the 'quality' of the ground effectes that muck.  For example, I live on a salt water saturated peninsula, so my ground is quite conductive.  However, in open desert I have quite literally laid my wire dipole on the sand and made NVIS contact with base - about 10-12 Watts output in CW - no problem.

Lower antennas reduce much of the NOISE so there can indeed be lower signal levels, but better signal to noise ratio often more than makes-up for that.


Here's my standard NVIS in the field antenna:  half wave dipole from above head level at any conveinent height when over normal or dry soil. If you can easily get it higher - fine, but you will not gain much, so remember that ANY antenna is better than no antenna.  On a reliable radio path, even a 'slant wire' over a limb with a 'counterpoise' "ground" laying on the ground or even a bit over the ground is fine for the <350 miles we are talking about, thoughit's a 'fuzzy' estimation.

Have a look at actual, measured antenna exxperiments on NVIS
per antenna heights.  The results will surprise you.


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


Time to go play radio......





>de RadioRay ..._ ._
« Last Edit: October 01, 2012, 12:27:37 PM by RadioRay »
"When we cannot do the good we would, we must be ready to do the good we can."  ~ Matthew Henry

White Tiger

  • Hero Member
  • *****
  • Posts: 526
  • SMeter: +11/-0
    • View Profile
Re: Setup for post-collapse communication with family?
« Reply #27 on: September 27, 2012, 10:08:47 PM »
Thanks for the informative post RaRay (apologies, I could not resist)!

In your opinion - how high would the NVIS antenna need to be in a swampy, loamy-soiled, environment...like say the Tampa Bay area?

I'm flirting with the idea of trying for my first QSO utilizing NVIS...
If you're looking for me, you're probably looking in the wrong place.

RadioRay

  • Administrator
  • Hero Member
  • *****
  • Posts: 790
  • SMeter: +45/-2
    • View Profile
Re: Setup for post-collapse communication with family?
« Reply #28 on: October 01, 2012, 12:56:39 PM »
Alll of this for NVIS is for a horizontal antenna, in this case a dipole.  Vertical antennas have a dead zone off the end that points toward that sky, which is why you do not want to use a vertical antenna for NVIS. Over wet soil (I am on a peninsua which projects into the Chesapeake Bay...) the math ways 1/4 wave over ground.  That would be roughly 32 feet on a forty meter antenna.

HOWEVER - real world experience as well as antenna modelilng software says that anything above your head -to avoid clothes lining yourself or others- is going to give you a signal UPWARD at high angle, which is what you want for NVIS.

1.  Antennas lower to the ground do have higher ground losses.

2.  Antennas lower to the ground receive much less noise and greatly reduce 'long range' signals, because the ground is focusing on what is received from over head (short range 0 - 350'ish miles) , rather than receiving signals which come in lower over the horizon, which you are not interested in for NVIS. This includes the noise from distant T-storms.

In Short:   Having a moderately reduced received signal strength with GREATLY reduced noise, gives you a higher "signal to noise ratio". This is a GOOD thing! Example: Hearing my guy at S5 instead of S7, but with the reduced noise level from distant T-storms and medium and long range interfereing stations = success for us because I hear much more of his signal that of the interference.

Tactically:  A low antenna for NVIS is :

1.  Less likely to be seen/recognised as an antenna at a distance. 

2.  Quick to deploy/tear down, so you are able to set-up rapidly when needed and to get-out-of-Dodge, should that be necessary.

3.  A low HF dipole produces far less ground wave, which can assist in avoiding accurate radio direction finding, should that even be an issue.

4.  NVIS is VERY difficult to radio direction find, especially if you transmit from a valley, gorge, culvert or even in an 'urban canyon' in a city.
    4.1  A 1x1 mile DF fix in rural Kanses might inculde a single farm house, while the same 'fix' in a metro area inculdes many thousands of
    people, cars driving  through & etc. // food for thought //


>>> Any outside antenns is better than no antenna - every time.  For the ham shack at home, it's bet to have a couple of different antennas for different uses/distances.  The HIGH dipole for medium & ong range, then the low dipole for enhanced NVIS as an example.


Even a 'slant wire antenna', that is a wire tossed into a tree with a wire as an antenna worked with a 'ground' wire along the ground can yield impressive results. Though far from the best, in a time pinch, you do what you have to do.  If it's lunch time on the trail, sand in a sock tied to a line tossed over a limb will get the antenna wire up quickly and that way you're not carrying lead sinkers in your pack... Why carry the extra weight?  //Be sure to dump the sand out of the sock before you wear it...  :P  //


Time for lunch and to play radio...


>Ray


>>> Here is a good sourch on a home installation to enhance local NVIS radio contacts, using a low loop.

http://www.wc5c.org/LinkClick.aspx?link=NVIS_Loop.pdf&tabid=394&mid=847
"When we cannot do the good we would, we must be ready to do the good we can."  ~ Matthew Henry

White Tiger

  • Hero Member
  • *****
  • Posts: 526
  • SMeter: +11/-0
    • View Profile
Re: Setup for post-collapse communication with family?
« Reply #29 on: October 01, 2012, 01:48:00 PM »
Thanks Ray, excellent article!
If you're looking for me, you're probably looking in the wrong place.

Radio Preppers

Re: Setup for post-collapse communication with family?
« Reply #29 on: October 01, 2012, 01:48:00 PM »