This article is still in progress. I went ahead and published it in case any of the information already here is useful to anyone. Check back for updates as time allows.
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.
Crimpers
Heat Shrink
Making vs. Buying Cables and Jumpers
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