(Continued from Part 4. This concludes the article.)
ANTENNA SELECTION
Mobile Antennas Selection, and Mounts
The following list is very short list as most antennas on the market require the installer to tune the antenna with an SWR meter. Often this fact is omitted. Fortunately, both these antennas do not need to be tuned and are more than adequate. There is not much need to look further. Both of these antennas have NMO bases, and there is a variety of heavy to light magenetic mount with various cable lengths available that have MNO fittings. Magnetic mount bases are very popular, yet they are not the only way to mount antenna without drilling a hole. There are several different types. Be sure to shop and find a mount that has cable that is long enough for your installation.
Diamond Antenna SPM/NMO Magnet Mount Mobile Antenna (NMO Mount)
Diamond Antenna K515SNMO Luggage Rack Mount (NMO)
Diamond Antenna K400CNMO Trunk Lid / Hatchback Mount
UHF and VHF Mobile Antennas:
UHF, high gain antenna intended for the GMRS and UHF business band range of frequencies between 462 and 467 Mhz: Midland MicroMobile MXTA11 6db Gain Antenna https://www.buytwowayradios.com/midland-mxta11.html
For VHF and UHF
Multi-purpose wide band, and dual band antenna on a magnetic mount intended for all radio services on VHF and UHF:
Tram 1181 Dual Band NMO Mount Antenna (140-170/430-470 MHz) https://www.buytwowayradios.com/tram-1181.html
A BASE STATION ANTENNA: THE SLIM JIM
KB9VBR Slim Jim Antennas
There are many choices, and we good down many rabbit holes and lose sight of what I believe is one of the best choices in base station antenna out there for the prepper. KB9VBR, Micheal, has lots of information on his website, and many YouTube videos. I got my only store-bought slim jim from him over a decade ago. He takes care of his customers. As I now do, he makes j-poles and slim jims for all radio services.
For the transceivers discussed, purchase a high gain ‘slim jim’ antenna here:
UHF for GMRS and business band frequenices select 462 to 470mhz.
In the option boxes, select ‘N Female’ or PL259 connectors.
High gain ‘slim jim’ antenna , 150 to 160 mhz, that can be used for MURS radio, and for your scanner, if a MURS radio is not in use.
VHF Public Safety, MURS, Marine, & Scanner Slim Jim Antenna
$48.00 – $52.00
Use the directions on the website to properly install the antenna. Although not recommended by the manufacture, it is wiser to use an RF (radio frequency) air choke on these antennas, and it certainly necessary on J-pole antennas to get the best performance. Make an RF air choke with a coil of cable that is approximately 4 inches in diameter, and 5 coils of cable. Secure with wire ties or cordage. This decouples the antenna from the cable. We do not want the cable to be a part of the antenna and detune it. This is very important to the antenna’s performance in terms of SWR and bandwidth.
My Experience with Slim Jim Antennas
Slim Jim type antennas are my favorite antenna that I have made for many different frequencies, or radio services, and tested and tuned with precision, over and over. These feature rugged construction, high gain, and have more bandwidth and gain of J-poles, and a lower noise floor with full quieting, or low noise to signal ratio. It is superior to the J-pole, but only requires a bit more material and work. It is less expensive to buy this one than to make it if you do not already have the supplies, and the skills of a plumber to sweat copper joints, and cut copper pipe with precision. However, you will likely be successful if when make your own using this Slim Jim calculator: https://m0ukd.com/calculators/slim-jim-and-j-pole-calculator/american-version/ The wide bandwidth makes this antenna forgiving. You can off on your measurements, and still end up with a usable antenna.
This example demonstrates that indeed ‘height is might’, and what a low power transmitter can do on a slim jim antenna. I’ve used my homebrew slim jim to talk to a 70cm repeater at about 6,200 feet in elevation, that was 80 miles away with a 4 watt Baofeng. Understand however, that this example had no obstructions to navigate. It was a straight shot, clear line of sight situation to the repeater allowing a strong enough signal into the repeater that the repeater broadcasted a clear crisp (5×5), and intelligible voice communication, with little to no noise in the background. It was ‘full quieting’. This is ideal, or in this case, phenomenal performance, given the low quality and low power transceiver used, a junky old nasty and dirty-RF Baofeng. My ham buddy had it on his antenna analyzer during this contact and experiment. My Extra Class acquaintance, who builds repeaters and antennas for a living, was in disbelief after scoffing profusely at the Baofeng.
The General Class fellow was so impressed he bought a slim jim antenna from me. My builds feature a tune-able 1/4 wave stud that dials these antennae in. As just a ‘hick in the sticks’, I’ve been forced to learn what can be done with nothing, a Baofeng, and with low power. In light of our not-so-bright future, this skill and experience attained, could prove to be very useful. Anyone can just turn up the power to get it done. Embrace low power and learn what you can do with it. If the guy on the other end sounds weak, if you sound weak to him, that is exactly the maximum power needed for a high-threat situation. Getting it done on very lower power makes it very difficult to intercept you. And if you aren’t intercepted and identified as a “target of interest”, then they won’t DF you.
We might see that most cost-effective radio communications can be had with an inexpensive radio that is on the best antenna you can afford. I believe the Slim Jim is one of the best for a Baofeng, or a full power transceiver. The advertised bandwidth of this antenna, 462 to 470 Mhz is a conservative estimate of the kind of bandwidth I would expect. My UHF Slim Jim builds uses 3/4 inch copper pipe, in place of 1/2 inch pipe typically use in construction of these antennas. It has a surprising bandwidth of 420 to 470Mhz. This is partly due to the fine-tuning involved to make the most of its increased bandwidth. Larger diameter radiators produce wider bandwidths. My recent Slim Jim build for the High VHF band, is centered on 153.000Mhz, and tested in the current installation location to be lower than 2.0 to 1 between 143.000 and 163.000 Mhz. From my perspective, this is ideal. One transceiver on one antenna can do nearly the whole usable High VHF band if necessary. It is an efficient use of resources, and funds. It is also a good use of space in the antenna farm that is the crowded roof, and good use of space in the ‘Ham Shack’. There are therefore fewer antennas, and few cables, and less RF noise in the shack.
UHF Propagation
A 4-watt Baofeng on one of these antennas on a 20 foot run of SI600 (LMR400 is suitable as well) cable would have an ERP of 6.4 watts. Under conditions where pine forests are present, I would expect a range of no more than 1 to 4 miles. Pine tree needles are of the length and density that absorbs UHF frequencies. If one is attempting to practice secure radio communications, this limiting factor could work to your advantage. If transmitting ‘down’ or the length of a valley with a river and flat land, and hills on both sides, with pine trees on those hills, unlike VHF, most of the signal will stay in the valley. UHF has its advantages, and is better to use than VHF in many situations. Deciduous forests do not have the same extreme effect on UHF, especially after they lose their leaves in the fall.
Low Power Propagation
Estimating the range of radio and antenna combinations are difficult as there are so many variables to account for. Hopefully, my estimates are accurate representations of the performance that is possible or actual in your neighborhood. We can certainly use a low-power handheld that transmits with 1 to 5 watts as a base station if the station is above the average terrain. And we might avoid the expenditure of the expensive mobile, if we have the best antenna we can afford. Low power settings, or low power transceivers, transmit in the power range that provides the most secure communication circuit at the maximum ranges when ideal, or good antennas are used.
If you need only one mile of range, do a radio survey of the area using only 1 or 2 watts from your base station. If the range is not adequate, then perhaps it is time to use a better antenna, or change the antenna height, but no more than is necessary to complete the necessary communication circuit. Hams seek to speak to as many contacts as possible, as far away as possible. Situation dictating, for secure communication, we should seek to do the opposite. We should limit our range, and who can hear us. We can use our GMRS antenna, and a handheld to accomplish a more secure method of radio communications as handhelds typically have power settings that are much lower than what typical base station transceiver offer — no less than 5 watts. If one watt is all that is needed, then that is all we need. The high gain antenna might double that signal to two watts ERP, and it will hear the very weak signals from other handhelds only use their attached antenna they come. In a war zone, low power is your friend.
In the case of GMRS that is often used, we are best served with low power and good antennas. If later you can afford a mobile, then by all means get one to talk further out, but use it only if the hand held will not do the job. GMRS 40 watt mobiles can talk much further than 4-watt CBs, and the mobile provides the power to talk to ubiquitous GMRS handhelds at extended distances that a patrol carries and must use to provide early warning of an attack, and to coordinate a defense.
The Final Step, Verifying the Operation of an Antenna
Always after an antenna is installed, check the SWR of the antenna. We are not only testing the antenna, but the location of installation, the connectors used, and the cable itself. If a connector is loose, a bad SWR would result, and can easily be corrected. And we should periodically, or when suspect, we should have a VSWR meter to verify that the antenna is still good, and is not doing damage to the radio. There are much better SWR meters out there. For this price, it is must-have. There are a plethora of instructional videos available demonstrating the use of this meter. This is lowest cost and the easiest to use SWR meter I know of:
Surecom SW-102
Conclusion
If further help is needed, feel free to ask, in the Comments to this article. If BuyTwoWayRadios.com cannot program a business radio for you, or you need a more personal approach other than e-mail exchanges, or if you need a Baofeng programmed, or other services not found here or elsewhere, then I would give Paul Strammer a call on the phone or send him an e-mail. He knows what preppers need, and will help with radio in a way few other can or will. He is a retired logger, a patriot, and General Class Ham living in Northwest Montana: Paul Strammer
I hope that you found the preceding helpful. – Tunnel Rabbit, out.
I hope that you found the preceding helpful. – Tunnel Rabbit, out.
Thank you TR. This is just the information I needed for radio communications. While I would like to do ham radio someday, it will have to wait until time and money allow. What you have provided (under 20miles) exactly fits what need. Thank you again!
One antenna I have found that is very reliable for a base station is the Arrow Antenna. I have a couple of the OSJ models (for 2M/440 and 220 band) that have been up and running since 2007 and I can hit repeaters in NC, SC, TN using 50W and this antenna. And I live in the mountains of WNC and we have had severe weather including strong winds/rain from hurricanes from the coast, snow, ice, etc., and my Arrow J poles are still going strong, even better than my higher cost Comet dual band. The Arrow’s are made from aircraft aluminum and very easy to assemble and put up on any mast. As far as a mobile antenna I prefer a mag mount and that way when I go into a parking deck I can just take off my antenna and just put it in the back seat with no problems and doing it that way only takes less than a minute.
Thanks for the articles TR, excellent info.
Hi Randy,
Arrow Antenna J-poles have a good reputation. I would have at least one of their yagi’s. It is also best to learn how to make these antennas, and how to repair antennas. Arrow Antennas has changed ownership. At one time yagis could be custom ordered for your particular center frequency, such as MURS and GMRS. There is not ERP limit for MURS, so we can take a 2 watt MURS hand held and use a yagi to boost the signal like a spot light intensifies light and casts it into a beam, greatly extending the range that two radios can talk to each other. Yagi also allow us to hear very weak signals from FRS hand held’s. It is like cupping your ear to hear a whisper.
I like 220Mhz because the yagi is more compact, and a 5 element yagi can be used and carried easier than a 2 meter 3 element yagi. 220mhz is almost as good as 2 meter in the woods. A 5 element yagi could have a gain of 11dBi and produce a signal strength, or ERP of about 30 watts if using a 4 watt Boafeng. If on foot, if the yagi has too much gain, thus a narrower RF foot print, the user will have a harder time pointing the yagi in the correct direction without using a map and compass. We want to avoid using a high powered transmitter on a omni directional antenna, if we can, but it would be good to have just in case our other efforts fail to contact the base station. If a patrol is in trouble, transmit and move several miles if you can if an omni directional antenna is used.
440Mhz is much more lossy in cables, but we actually do not wish to have an ERP of more than 10 watts in most cases. UHF does not do as well in the woods, but can shine if one wishes to keep the splash from leaving the area you need to communicate with. This is an especially desirable attribute if operating from a base station. If things get bad, real bad, a base station should only risk transmitting with yagi. A 12 element 440Mhz yagi is manageable, and produces a very narrow foot print. If talking between base stations, both should use yagi’s. If I could, I would only send 250mw threw this yagi. I could use even use an FRS radio that has been modded to accept an antenna connection because I want a very low powered transmitter.
This is best for a base station to use. Point a 5 to 12 element 440 yagi down a valley and into a hill side on the opposite side. Use only 1 watt, I can calculate the ERP, but it is not so important as the narrow RF footprint. Odds are the splash from the transmission will be too weak for others to over hear. All this talk about how to control our RF, and what is a truly a secure signal, would go to serve us well in the worst case scenario that could be in our future if we must deal with an invading force. There are many techniques to use, and not enough time to get into all of it here.
If you can get an HF set, and set up what is loosely termed here as a Near Vertical Incident Skywave dipole, that is basically a dipole that is less than 32 feet hieght, ideally 25 feet, and as low as 10 feet high, and get a OTP generator from Ready Made Resources, this is the least technically challenging, and the most secure means of communication in a war zone, and can be accomplished for very little money. We are going to need more warriors with radios, and Hams can quickly employ this. Of course digital modes would be helpful, but they are not absolutely necessary if transmitting Short Skip (NVIS). You would be DF proof if there is no interception station within 25 miles. I’ve been told by experts in the business that this is so. This is not Internet rumor.
Others who are interested in learning more, I send you to brushbeater.org run by NC Scout. Down load the articles there. What he will give you is proven on current battle fields. He has real world experience on a battle field.
Randy, T. Rabbit is correct about the HF NVIS and OTP combo. Satellites not withstanding of course. Because while more than 25 miles away they have clear line of sight. Send your traffic and run like heck and very little of tactical value is gained by nation state actors (NSA). So sayeth this pro.
After reviewing your articles on comms in its totality is can see what you are doing and the angle you’re coming from. I like it. I think I can best help by pointing out things from the NSA perspective. To a certain degree of course. I learned the ropes at the Center for Information Dominance Corry station before being forward deployed in the fleet at first as an EW (electronic warfare ) then later a CTT ( cryptologic ). Cannot and WILL NOT CROSS THE LINE, but will chime in where I can help. By the way I left a link for you on your previous post TR.
I did my best to explain Near-Vertical Incidence Skywave (NVIS) HF in the Radio Ranch chapter of my first novel, Patriots. Only the most sophisticated government agencies (NSA and strategic level MI) have access to true HF-DF equipment. That requires a very long DFing baseline (ideally, hundreds of miles), chirp sounders for gauging the current ionospheric layer propagation conditions, and some sophisticated DFing software. Best regards to a NSG veteran from an ASA veteran.
Got the link and made remarks there.
About NVIS propogation.
Thanks for the validation in general and about NVIS. Years ago I tried to get my Ham buddies into NVIS, and they just do not want to do anything more that what they already know. There is always resistance to change. The larger the club, the more resistance. Few are forward thinkers and leaders, so you’ll have to shop around in the quest to find some one who will participate and break new ground. If no one else is doing it, no one wants to join in. Education is the answer, and necessity will provide the motivation, but we need to develop the skills to operate this way now if we can. At the very least get the knowledge. Even though I cannot find anyone who wants to play now, I will learn all I can by reading.
This type of propagation is nothing new, it works. Relay stations every few hundred miles would be unstoppable. Hams need to get together and practice. The antenna is cheap and easy to set up dipole less than 1/2 wave length off the ground, so there is little practical barrier to get started. Start with a dipole for 40 meters, and just get it high enough so that others do not walk into it. It really is that easy to get started, and play with it. There are other configurations that make it easier to operate. Use it locally and regionally. Information is every where. Down load the content from this link.
https://kv5r.com/ham-radio/nvis-antennas/
Thank you for this excellent 5 part article. I’ve been pondering a HAM for years…
In the mid 80’s, I was deployed to the National Training Center in So Cal., not my first rodeo, I made an antenna from fiberglass cammo poles and braided copper wire connected to a cheap, radio shack 40 channel hand held CB and could talk clearly to central Louisiana from very close to the death valley.
Now reconsidering a radio and thanks for the reawakening.
Thank you for the very informative series of information TR. Years ago I purchased a dozen or so Baofeng radios that JWR recommended ‘just in case’. I have no interest in transmitting with them as intended, just using them for listening and possible walkie talkie use. Your post has motivated me to open the case of radios and see what I have and figure them out for possible use.
Good post TR
Thanks a lot for this informative series.
T R, has anyone published instructions that are readable and understandable for the Baofeng radios?
Even if you can do Chinglish, I an not aware of any printed manual that is clear and concise. This often the case with many owner’s manuals that are written by those who are technically inclined for the masses. But there are scores of helpful videos on YouTube. Some are better than others. Here is one from a fellow who has done a ton of instructional videos and knows his stuff.
https://www.youtube.com/watch?v=tyHwAq7w9QE&t=1185s
BTW, if I disappear today, it is because my internet connect went down.
http://radiodoc.github.com
Uv5r user guide in plain language. Hope that helps.
Got it. Thanks!
I might of missed it mentioned in the article, but an excellent site for information on the Baofeng radios is https://www.miklor.com/. Tons of info there. They do cover other radios also.
I have built several Slim Jim antennas for a small group of us that use Baofeng radios for GMRS comunication. I live in an area that is full of hills and valleys. We do have a repeater in the area, but with the Slim Jim, we are able to talk to everyone without use of the repeater.
Great article, thanks for your work in putting this together.
Excellent 5 part article, that should be saved. Tunnel Rabbit covered the need to know information, with references for further knowledge.
…….. The ‘powers to be’ in our country and around the Globe, are activity trying to censor the opposition. A fence between the USA and Mexico is bad; a fence around our Nation’s Capital and the American People, is called ‘good’ by our crookedly elected elites.
++++++ At some point, the outrageous spending by our politicians will catch up with the people of America. Prep now. An independent source of communications is worth having available.
The Tactical Baofeng.
One of the reasons not to use a Baofeng for serious tactical work, is that that the plug where ear and mic sets plug in, quickly become loose and unreliable. Not every one needs head set, so purchase a few really good hand helds and head set that are indeed rugged, or make sure the TL (team leader) has access to replacement Baofengs. As a poor country boy, I might even resort to extreme measures such as using JB Weld epoxy to make sure the plug is not subject to movement, yet the ear piece is also fragile and will have to be replaced sooner rather then latter.
Fortunately I do already have a few better quality ear pieces, but these have Kenwood plugs that do not fit into Baofeng radios, but fit my very low powered that are no more than 250mw radios that are also scrambled. Even if OPFOS ( a gang could be OPFORS, Opposing Forces) can hear our traffic, it would be unintelligible. And even if they could understand the traffic, they would not understand the brevity code, and they would be so close that you would not loose tactical surprise. The scramble feature also provides the illusion that the transmitter is further away than it actually is. Also, we should use a tone to avoid being jammed with an hot mic. At the squad level, they will not have the equipment to discover the tone that you are using if they even suspected that a tone was in use. They cannot hear it.
This head set from Ready Made Resource is a good example of what the TL (team leader) should have. Even if it is of good quality, we’ll still need several replacement sets. We actually do not want the rest of the fire team or squad to fill the air with chatter, and unnecessary RF anyway, and we probably can not afford to out fit every one with the best we can afford. Learn to use arm and hand signals, and if one day the radios are too risky to use, you’ll not be without.