In the world of radio, you can never have enough patch coax cables, connectors, or converters. It seems like everytime I think I finally have everything I could ever need, I come across a situation where I need to either make or buy another coax cable or jumper. In the article below I will discuss some of the pros and cons of the different ways to handle these situations, and what brands I trust for coax, connectors, crimpers, etc.
Converters
A converter will change one connector type to another. It can change the gender, the connector type, or both. You generally will want to use a converter when you simply need to change a connection type and not when you may need to extend the connection or provide some form of stress relief to the connection. You can start off buying just what you need when you need it, or you can go for the gold and get a large pack that will cover a lot of options. I personally recommend starting off with just what you need until you find a supplier, brand, and connector type that you like.
Connectors
A connector is what is on the end of a coax cable or on a radio. There are a lot of different types of connectors, each type has a specific purpose that it works best for. depending on your use case, there will always be one or more connection types that can work, and it is up to you (or a manufacturer) to decide which one to use.
SMA Connector (DC to 25 GHz)
SubMiniature version A connectors are one of the most common for smaller radio devices like handhelds due to their small size and ability to handle UHF frequencies up to 25 GHz. It is not considered water tight, and is rarely (if ever) used for exterior connections.
BNC Connector (DC to 4 GHz)
Baby Neill Constant or Bayonet Neill–Concelman depending on which story you believe. These are another one of the most common connectors for smaller radio devices like handhelds and some instruments due to their small size and ability to handle UHF frequencies up to 4 GHz. It is not considered water tight, and is rarely (if ever) used for exterior connections.
PL-259 and SO-239 Connectors (DC to 300 MHz)
Plug, Lanyard and the military designation number 259, and its mate the SOcket and the military designation number 239, sometimes called a UHF connector. Contrary to its common name “UHF connector”, these connectors are in fact not very good for current UHF frequency range. It was so named back when UHF meant any frequency over 30 MHz. These connectors can really only handle frequencies up to about 300 MHz, which is the start of the modern UHF frequencies of 300 MHz to 3 GHz. If you want a fairly stand connector that will work with lots of radios, coax, and antenna options, or if you just don’t need the higher frequencies or water-tight seal of the N-Type connector, but you still want to use the larger diameter coax cable to limit signal loss these connectors may be the way to go. You will find this connector on some dual band (VHF/UHF) radios. Even though the PL-259/SO-239 connectors are not ideal for the UHF side, they will still work to an acceptable level. These connectors can be made watertight with the use of a special Weatherproof Self-Fusing Silicone Rubber Sealing Tape applied to the outside to seal out the elements, usually covered in a layer or two of 3M Scotch Super 33+ Vinyl Electrical Tape or similar electrical tape to protect the self-amalgamating tape from the UV light and to ensure it doesn’t unwrap.
N-Type Connector (DC to 11 GHz)
If your use case will need to handle UHF (Ultra High Frequency 300 MHz to 3 GHz), accommodate a large low-loss coax, and/or be watertight for exterior connections, the N-Type connector is the way to go. This is a standard for UHF communications, and is considered a more professional connector by many. It is physically larger than a PL-259 connector, and it seals water-tight to keep out the elements that can cause corrosion.
Coax
There are many different sizes and types of Coax (Coaxial Cable). When it comes to choosing coax, it will usually come down to 3 main factors: frequencies supported, signal attenuation over distance, and price. There are other factors, but these are the big 3. When selecting coax for your application, you need to first make sure that coax can handle the frequency range you intend to use.
Selecting the Proper Coax for Your Use Case
If you’re only using VHF/UHF frequencies, you don’t really care how well the coax handles HF frequencies and vice versa. So figure out what frequency range you need to cover first. Next you will need to check the coax’s specification to see how much signal attenuation (power loss) you will experience on those frequencies at whatever distance you will need to cover. Coax is usually rated for how many dB (deci Bells) of power loss you will experience per 100 feet at a given frequency. If your coax will only be 5 feet or less, it won’t really matter much since the loss in that distance is negligible. If you’re going more than 50 feet however, it will start to add up. 3dB of attenuation will drop your effective power out level to 50%, 6dB will drop it to 25%, and 10dB will reduce your power output to 10% of the power you feed in.
Once you have figured out what frequency range(s) you need, how far you need to go, and what kind of loss you can accept, the next step is to figure out the physical specifications you need. Will the wire need to be able to go through fairly small holes, or have sharp bends in it? Will it need to be used for portable use, or fixed position? Are you going to be running something that requires hardline (Heliax) like a repeater? The physical characteristics of the caox will affect all of these requirements. We will discuss some of these characteristics below, starting with Coax diameter and how it affects your choice. Keep in mind, if you look at 10 difference manufacturers of a certain coax type (like RG-213), you will probably get 10 different specification sheets.
Smaller Diameter Coax
If you have to fit the wire through a small hole and don’t have far to go, you will want to look at types like RG-316 (0.102″ diameter), RG-58, Hyperflex 5. These smaller diameters are also great for short (10 feet or less) patch cables (also called jumpers). Since they go such a short distance, the loss will be negligible and the size and flexibility are a plus for jumpers. Some mobile mounts use a VERY thin coax like RG-316 that can fit through a small opening, like the edge of your hood, and then connects to a slightly larger coax like RG-58 to keep the overall line loss to a minimum. You may also see thinner coax used when stress relief is an issue, like on SMA connectors or when connecting your HT to a mobile or base antenna. Because the weight and the stiffness of larger coax could put undue stress on the radio’s connector and cause it to break, a short stretch of thinner coax is used as a strain (or stress) relief.
Examples of Small Diameter Coax
RG-316 (0.098″)
RG-174 (0.100″)
Belden 8259 (their RG-58) (0.193″)
LMR-200 (0.195″)
RG-58A/U (0.195″) –
RG-400 (0.195″)
M&P Airborne 5 (0.200″)
Medium Diameter Coax
Medium diameter coax is often a nice middle ground. It is still small enough and flexible enough for most use cases, and it will result in a lower line loss, while still keeping the cost down. Anytime you aren’t going more than 50 feet, or you can take a little line loss, or you just want the lighter weight or better flexibility, the medium diameter coax is going to be your go-to coax. I use RG-8X for a lot in my shack, and it is definitely my go-to for POTA or EMCOMM. I like the fact that RG-8X is a nice middle ground for things like jumpers or patch cables. The connectors are readily available, and inexpensive. I have started to move more to the Messi & Paoloni (M&P) Ultraflex 7 for some of my longer runs since it has AMAZING specs for not much more cost. Ultraflex 7 has much better specifications than RG-8X, and is even better than some thicker coax like RG-213 on most frequencies.
Examples of Medium Diameter Coax
RG-8X (0.242″)
LMR-240 (0.24″)
M&P Ultraflex 7 (.287″)
Large Diameter Coax
Large diameter coax is generally used when you have a longer run to cover, need to handle more wattage, or when you cannot afford a lot of line loss. These all generally go hand-in-hand.
Examples of Large Diameter Coax
M&P Ultraflex 10 (0.400″)
LMR-400 (0.405″)
RG-8 (0.405″)
RG-213 (0.405)
Hardline or Heliax
When you hear someone talking about hardline, or Heliax, they are talking about coax that is usually used only for a use case like a repeater or a permanent commercial transmitter site. Hardline can typically handle more power than other types of coaxial cable due to the materials and thickness used to make it. Hardline is a generic term for the coax, whereas Heliax is a brand name of a type of hardline. Hardline, as the name says, is not very flexible at all. In fact, if you bend it into too tight of a radius, or if you bend it too many time, it will destroy it. It is generally meant to be installed once and be left alone to last a lifetime (more or less). It is EXPENSIVE, and so are the tools and connectors you need to install it. However, if you want to be able to handle high wattage, need extremely low line loss, and can’t have any static that can be caused by the movement of your feeder line, this is the way to go.
Hardline is usually referred to by its diameter in inches, at least by Heliax. It is available in sizes from 1/4″ up to 6-1/8″, but you will usually see more common sizes like 1/4″, 3/8″, 1/2″, 7/8″, or 1-1/4″.
Crimped vs. Soldered Connectors
If you are going to be making jumpers or cables, you will need a good set of crimpers and probably a high wattage soldering iron/gun. If you buy some of the more expensive compression/sealed connectors like the ones Messi & Paoloni make, you will need a high wattage soldering iron/gun and some wrenches.
For most of my short jumpers or even some of my POTA cables, I prefer to use crimp-style connectors. They are quick, easy to install, and inexpensive. I pay around $3 USD per silver-plated PL-259 crimp connector versus $10 per Messi & Paoloni enhanced solder connector. Don’t get me wrong, the Messi & Paoloni is worth the extra for my more critical or permanent installations, especially if I need a long run of coax or the coax and connectors will be outside in the weather. Plus, I loved the fact that with their connectors I can remove them and re-install them multiple times versus the single-use nature of the crimp style. However, when I am making 10 – 20 jumpers that will only connect equipment that will be used inside and have a length of 3 feet or so, I usually go with the cheaper crimp style connectors and lessor quality coax to keep the price down so my wife doesn’t start looking for a non-Ham to marry, lol.
Heat Shrink
Whether I am making a short coax jumper cable or a longer coax feedline cable, I always use some marine-grade 3:1 heat shrink on the ends of the cables. There are 2 main reasons; first, I like that it helps seal out the water or moisture from being able to easily penetrate the coax. Second, and just as important, I like to color-code my wires so they are easier to trace out when I need to connect or disconnect them. I will use all one color for each rig so I don’t accidentally plug-in or unplug the wrong wire when there are several rigs in one small area. I might use all red for my FT-991A, and all white for my FTM-200DR. Lastly, heat shrink can act as a strain relief for the wire. It will help keep the coax from repeatedly flexing where it connects to equipment, which will prolong the life of the coax.
Making vs. Buying Cables and Jumpers
This is a personal preference, but I can help you make a decision if you are on the fence about it. Production made coax cables are usually made well, by people who do that all day long everyday. Does this mean they can’t/don’t make mistakes? No. But, it is not likely as long as you ar ebuying from a reputable brand or supplier. However, you will pay more, and you will still need to test your cables before you trust your expensive equipment to them. If you make your own cables, you will have a lot more freedom to cater to your needs and price range. You can buy cable in bulk to save some money, and the same goes for the connectors. You may spend more upfront that if you just bought them initially, but if you will be making a lot of cables, or just want to be able to make them to your needs, the custom fabrication path will pay off in the long run (pun intended). There is also a middle ground, where you buy prefabricated coax in long runs with ends already attached, then cut it to shorter lengths and reattached new ends as needed. This is a good option if you just can’t find a good supplier for bulk or by-the-foot cable. The cost of the crimpers or soldering iron (if you don’t already own them) and the connectors are the part the add the most cost to this method, so keep that in mind.
Recommended Products and Distributors
Buy Two Way Radios
If you want Messi & Paoloni, Tram coax or antennas, Wouxun radios, Motorola, Icom, or Kenwood business radios, or other products, I can highly recommend Buy Two Way Radios. There are only a few distributors for Messi and Paoloni in the USA, and they were the first that I found who carried it. They have great prices, and fast delivery. Their salespeople are very nice and knowledgeable. I am lucky enough to live only a few miles from their Rock Hill South Carolina location, so I have met several of them in person – plus I LOVE not having to wait for a delivery! I get all of my Messi & Paoloni products from them, as well as any of the coax, connectors, antennas, and radio accessories that they carry.
Messi & Paoloni
I can highly recommend Messi & Paoloni products as being the best I have found on the market for the highest quality cables and connectors. They are made in Italy, and I have heard them recommended by the DX Commander himself, Callum McCormick M0MCX! It costs more than other cable and connectors, but the quality is the highest, and it is “buy once, cry once” and well worth it.
Max-Gain Systems
In my search for high-quality, silver-plated connectors, I found Max-Gain Systems. This is where I get most of my crimp-on style connectors and adapters. Their products are top-notch, and I have always had great service from them. They even sell fiberglass poles for building antennas like the Hex Beam.
DX Engineering and Gigaparts
When I need a radio, specific antenna, or something the smaller retailers just don’t have, I go to either DX Engineering or Gigaparts. These guys have it all. Once again, knowledgeable and friendly sales people, and fast shipping. I have a few other suppliers I check, but I usually go straight to these 2 if I can’t get it from Buy Two Way Radios locally.