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Padre in the woods
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Antenna is everything in comms. You want that signal in local comms to travel horizontally from the antenna, with the least amount going up into the sky or down into the earth. Frequency selection is also important with terrain.
 

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Antenna is everything in comms. You want that signal in local comms to travel horizontally from the antenna, with the least amount going up into the sky or down into the earth. Frequency selection is also important with terrain.
Isnt horizontal config used for long distance and vertical for local, seeing most local antennas are vertical? My vision is to have both configurations on one quad beam which wouldn’t be difficult, 2 connectors and a switch.
 

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There are tons of CB radios still being sold in the US and worldwide.

I think what may have led to the decline in activity was that there was a peak during the oil crisis when everyone bought one. Also Home Owners Associations don't permit outside antennas so you won't see many house antennas in suburbia. Everyone now has cellphones so they have a false sense of security in that they dont need a CB. But they will when SHTF.

That said, a CB with AM/SSB capability is an essential piece of gear to have if you are a prepper. Installing a hidden antenna at home if you are in an HOA is not that difficult. If you want a mobile installation, a LARSEN NMO-27 is a perfect antenna for most vehicles. If you have a newer jeep with plastic roof, you need to be creative. Every antenna needs a counterpoise. This means an RF ground return for the radiating element. I suggest an ARRL handbook and ARRL antenna book for research. Many of the "CB" sites have poor information.
ok hoa girl here...how to hide one info pls.
 

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A half wave dipole hidden in the attic, for those that can't erect one outside. Or even hidden along side the gutters. Half wave dipoles, cut to frequency, are one of the greatest antennae out there.

Two thumbs up on the ARRL antenna book. Lots of ideas.
oops sorry i didnt get here before i posted...
 

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Padre in the woods
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Isnt horizontal config used for long distance and vertical for local, seeing most local antennas are vertical? My vision is to have both configurations on one quad beam which wouldn’t be difficult, 2 connectors and a switch.
H-pol favors long distance communications, but V-pol still works. Where you get into the H versus V question is when you have a local mobile operating with a whip antenna on a vehicle. H-pol is possible on a vehicle, but very impractical.

The comms I was referring to; the local community of survivalists/preppers will use V-pol with modified radios. Their two uses are normal speech for communication in the region, usually on common CB frequencies. But some have adapted radios to the Kantronics KAM-3+ and use it for messaging.

They will use the radio on a pre-agreed frequency and time, send their messages, and sign off. While a voice communication may be easy to listen to, trying to figure out what frequency the packet will be sent on, and at what time, would be hard. The image below shows a message my neighbor decoded, which took several weeks to "catch" the transmission.

Font Paper Monochrome Number Document


No clue who sent it, no idea who the message was sent to. My neighbor had been receiving interference, and just happened to be on the channel with a radio set up with his packet TNC. Quoting: "The message on the left was received at 10:22 Eastern, Friday, April 10, 2020, on the frequency of 26.312500 MHz, narrow band FM. I just happened to catch this as I was monitoring for broadcast RPU traffic on 26.310 MHz."
 

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"TURGID FLUX"
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ok hoa girl here...how to hide one info pls.
CB radio usually uses vertical antennas base to mobile.

Look up 1/4 wave ground plane antenna on the internets for an idea on how they work. A quarter wave on CB is going to be in the order of 102-108 inches depending upon the design, wire gauge etc. Make it long, tune by shortening.



Here is a vertical ground plane made with ~ 101-102 inch 18 gauge wire radiator plus four 102 - 116 inch radials . supported by fishing line from 20 feet overhead.


If you don't have a tree, you could make one with a vertical ~ 102 inch copper pipe supported from a 10 foot schedule 40 PVC pipe and run out four wire radials from just below the junction. Paint the pipe to blend with sky or put a small flag on it!
 

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"TURGID FLUX"
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H-pol favors long distance communications, but V-pol still works. Where you get into the H versus V question is when you have a local mobile operating with a whip antenna on a vehicle. H-pol is possible on a vehicle, but very impractical.

The comms I was referring to; the local community of survivalists/preppers will use V-pol with modified radios. Their two uses are normal speech for communication in the region, usually on common CB frequencies. But some have adapted radios to the Kantronics KAM-3+ and use it for messaging.

They will use the radio on a pre-agreed frequency and time, send their messages, and sign off. While a voice communication may be easy to listen to, trying to figure out what frequency the packet will be sent on, and at what time, would be hard. The image below shows a message my neighbor decoded, which took several weeks to "catch" the transmission.

View attachment 386028

No clue who sent it, no idea who the message was sent to. My neighbor had been receiving interference, and just happened to be on the channel with a radio set up with his packet TNC. Quoting: "The message on the left was received at 10:22 Eastern, Friday, April 10, 2020, on the frequency of 26.312500 MHz, narrow band FM. I just happened to catch this as I was monitoring for broadcast RPU traffic on 26.310 MHz."
That is some cool stuff. Would love to install a simple MDT/TNC system in the vehicles if for no other reason, keeping the grocery shopping list updated.
 

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Padre in the woods
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I'm sure it could be done, but I don't know that anyone has done it yet. There was a guy, (who I had a brief e-mail exchange with), who was in NH or VT, up by the Canadian border. He was considering using one of those small thermal printers like you see in retail to print out messages in cars. Not sure where he's at with that. His base used a a "Sirio 5/8-wave" antennas. Never heard of the brand, but it appears to be "interesting". Modelling in Ez-NEC shows a good pattern off the antenna. You have to replace one section of tubing to make it tune down to 25-26.8 MHz.
 

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A half wave dipole hidden in the attic, for those that can't erect one outside. Or even hidden along side the gutters. Half wave dipoles, cut to frequency, are one of the greatest antennae out there.

Two thumbs up on the ARRL antenna book. Lots of ideas.
a half wave horizontal dipole is going to be cross polarized with the vertical antennas everybody else uses. A ground plane in the attic (about 9’ tall)will work with no metal roofing.
 

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I'm sure it could be done, but I don't know that anyone has done it yet. There was a guy, (who I had a brief e-mail exchange with), who was in NH or VT, up by the Canadian border. He was considering using one of those small thermal printers like you see in retail to print out messages in cars. Not sure where he's at with that. His base used a a "Sirio 5/8-wave" antennas. Never heard of the brand, but it appears to be "interesting". Modelling in Ez-NEC shows a good pattern off the antenna. You have to replace one section of tubing to make it tune down to 25-26.8 MHz.
Sirio is well known Italian firm which supplies communication antennas for maritime, aviation and public safety use. Wide band VHF base antenna we had at remote base was only unity gain, but rated for 500w continuous duty CW or data, with VSWR NTE 2.0:1 from 136-174 MHz and to withstand 150km/HR wind load with 2cm of ice. Good choice of antenna for remote location.
 

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H-pol favors long distance communications, but V-pol still works. Where you get into the H versus V question is when you have a local mobile operating with a whip antenna on a vehicle. H-pol is possible on a vehicle, but very impractical.

The comms I was referring to; the local community of survivalists/preppers will use V-pol with modified radios. Their two uses are normal speech for communication in the region, usually on common CB frequencies. But some have adapted radios to the Kantronics KAM-3+ and use it for messaging.

They will use the radio on a pre-agreed frequency and time, send their messages, and sign off. While a voice communication may be easy to listen to, trying to figure out what frequency the packet will be sent on, and at what time, would be hard. The image below shows a message my neighbor decoded, which took several weeks to "catch" the transmission.

View attachment 386028

No clue who sent it, no idea who the message was sent to. My neighbor had been receiving interference, and just happened to be on the channel with a radio set up with his packet TNC. Quoting: "The message on the left was received at 10:22 Eastern, Friday, April 10, 2020, on the frequency of 26.312500 MHz, narrow band FM. I just happened to catch this as I was monitoring for broadcast RPU traffic on 26.310 MHz."
long distance communication ( meaning sky wave) doesn’t care about polarization because the ionospheric reflection can change polarization. Near vertical incident sky wave doesn’t care about polarization- if it did the choices would be east/west or north/south. Ground wave ( more or less line of sight) is very polarization dependent. In perfect case ( microwave or satellite dishes with clear line of site) we can send completely different signals on vertical vs horizontal.

BTW commander technologies sells a commercial grade colinear CB antenna. 0dBd gain. I bought a few for government C3 facilities. Shipping is a killer for pro antennas, but IIRC these were 2 piece.
 

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Padre in the woods
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long distance communication ( meaning sky wave) doesn’t care about polarization because the ionospheric reflection can change polarization.
Is this an personal observation, or based on signal propagation studies and models?
 

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Is this an personal observation, or based on signal propagation studies and models?
All of the above. The most common non ham use of HF uses a horizontally log periodic antenna or a Omni elliptical-horizontal antenna at the master station, and a blend of whip and horizontal wire antennas at remote stations . It works, and over time you don’t see any significant variation between signal strength on horizontal and vertical stations with non resonant antennas. ( my experience is with 35 or 32’ whips- with maybe a few 23-25’ vs long wires or dipoles. ) Ships and boats for example are usually vertical, while planes are horizontal ( cargo and military) or vertical ( vertical tails of airliners) The only place where skywave polarization plays a significant role is with two elipitical-horizontal ( fancy term for almost circular polarization) If an antenna is miss wired, it will be counterclockwise, where as most North American stations will be clockwise. You notice this quickly. The Faraday rotation has no affect on the signal strength of a circular polarized signal ( measured on a horizontal, vertical, or CP antenna)

AF, USCG, NASA, and ARINC propagation models match this behavior. Marine ship to shore calls are (were) almost allways completed with a RLPA ( horizontal) at the carrier site ( ie WLO in Mobile) and a vertical antenna on the ship. NASA ship to shore or KSC to remote site calls work the same way- mostly fixed LPA horizontal antennas at KSC with whips on ships and a mix of antennas at remote sites.

Note prior to FAA allowing use of Irridium, trans polar flights couldn’t leave the US unless ARINC could assign a workable HF frequency ( Inmarsat doesn’t work near the poles- generally north of 80-82 deg). And it’s still used as a backup, and for aircraft without SATCOM. Note ARINC uses a combination of vertical Omni, elliptical, horizontal and vertical LPAs. Take off angle and gain usually drive selection. Last I heard, pre COVID, ARINC HF traffic was still increasing, as more operators added high frequency data links.
 

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Padre in the woods
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You're mixing in a lot of statements which have no relevancy to the issue of h-pole vs v-pole transmission in regards to long distance propagation; and introducing statements having no factor to the question. My question is scientifically based on propagation models studied by Carl E. Smith and George Jacobs, many of which were used in military and industrial models. These are physics proven from early days of radio to now, which can not be changed.

I think we need to both disagree with the other, shake hands and walk away. But ask yourself, if v-pol is as efficient as h-pol in transmission, why did the VOA and international broadcasters invest so much money and land into h-pol facilities when the delta in costs is roughly 18 times?

I'm not disputing a v-pol transmission can achieve the distances of an h-pol signal. What I am saying is that the efficiency and dependability is much greater in h-pol.
 

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You're mixing in a lot of statements which have no relevancy to the issue of h-pole vs v-pole transmission in regards to long distance propagation; and introducing statements having no factor to the question. My question is scientifically based on propagation models studied by Carl E. Smith and George Jacobs, many of which were used in military and industrial models. These are physics proven from early days of radio to now, which can not be changed.

I think we need to both disagree with the other, shake hands and walk away. But ask yourself, if v-pol is as efficient as h-pol in transmission, why did the VOA and international broadcasters invest so much money and land into h-pol facilities when the delta in costs is roughly 18 times?

I'm not disputing a v-pol transmission can achieve the distances of an h-pol signal. What I am saying is that the efficiency and dependability is much greater in h-pol.
BZ

NNNN
 

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My original statement was “long distance communication ( meaning sky wave) doesn’t care about polarization because the ionospheric reflection can change polarization.” This was addressing the issue of having to match polarization on each end of a link. I provided about a dozen examples of mission and life safety critical long distance networks implemented without regard to polarization.

H pole antennas skywave are not dependent on a ground plane, therefor as larger antennas are deployed, and at lower freqs, H pole doesn’t require massive ground plane for omnis, and allow shorter towers for RLPAs. Without a near perfect groundplane, vertical antennas have little or no radiation at really low takeoff angles- impairing really long distance skywave. Horizontal LPAs are a great fit for international coverage as they have a wide beam width,and a low takeoff angle ( if chosen at construction.) Takeoff angles are changeable. If you look at an example with omnidirectional antennas, and intermeadiate range they use V poles- look at WWV./ WWVH.

the ideal technology for long distance skywave is circular polarization, but you need expensive bulky antennas, and for them to be efficient you need antenna height. I used to have a 12 site spiracone network, and it was the only way I could get 95-99%+ connectivity from Atlanta to Alaska without using at least one directional antenna. I am told previously Atlanta could reach the Canal Zone with similar reliability. That’s at 1 kw, mid morning in Atlanta.

BTW therotical models work poorly at HF frequencies for calculating polarization rotation. Too much variability, plus the rotation varies with the inverse square of frequency. Move out of HF, and stick with signals that penetrate the ionosphere, and they are extremely accurate, and used to set LNB skew on every satellite link in the world. I don’t know about troposcatter- they don’t get significant rotation in my limited experience.
 

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"TURGID FLUX"
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Faraday rotation. Diversity receiving antennas.

Sent from my SM-T350 using Tapatalk
 

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Faraday rotation. Diversity receiving antennas.

Sent from my SM-T350 using Tapatalk
That’s so rarely implemented in HF, particularly polarization diversity. The closest thing is circular/ eleptical antennas with controlled take off angles, so you get an antenna that works better than a 1/4 wave whip over a perfect groundplane AND a 1/4 dipole at the same time. (Because it’s horizontally biased some what, maybe as well as a 1/4 wave vertical.). The downside is you need to flip a switch to select takeoff angle- and there are nulls straight up- so no NVIS capability.

Or stick with CP at both ends and you can totally ignore faraday rotation.
 
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