Mobile hf radio grounding

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Mobile antenna grounding

Beep beep! Going mobile. Installing a ham radio mobile station in an automobile is often the next step for many hams following the establishment of a home station or perhaps as the upgrade from an HT. A ham radio mobile installation greatly expands the utility of amateur radio and increases the opportunity of time to get on the air. Just consider it yet another opportunity to learn and to expand your growing ham knowledge! Let me state from the git-go that there are probably a million feasible different ham radio mobile equipment combinations, installation methods, and techniques for achieving a well performing mobile station in your vehicle. But no matter your individual selection of transceivers, antennas, mounting methods, coaxial cable routing, operating bands, and other factors, some common tenets of mobile installations apply and help to avoid or reduce problems that are inherent in the mobile environment. Much like antennas, every ham radio mobile station is a compromise, but I came close enough to achieving the goals above to be happy. The transceiver s and related components such as an antenna tuner usually reside within the passenger cabin. A ham radio mobile transceiver may be a single contiguous unit or it may have a detachable control head, allowing the bulk of the radio chassis to reside out of sight, perhaps under a seat or in a stowage compartment. The power leads will be routed into the engine compartment to the car battery, while coaxial cable will be routed out to the antenna attachment locations on the exterior of the vehicle. A mobile station installation will require careful planning and component selection to ensure a well-integrated system that suits your needs and meets your mobile operating goals. The Transceiver: Besides your budget, your selection of a transceiver will be driven in large part by the bands on which you wish to operate. While variations exist, mobile transceivers tend to follow one of three primary styles:. With that assumption, the decision then turns to whether or not you want to have HF mobile, too. If you do want to reach out to greater distances with single sideband using the ionospheric skip provided by HF, the decision tree then branches to one of these two common transceiver arrangements:. My choice was a compact all band, all mode transceiver from Yaesu, the FTD. It supported several of my mobile station goals nicely:. Alt link. I clamped mine onto the left side of a console tray in the cabin, arcing the ball joint arm up and to the right so that the control head resides above the center of the console just in front of my gear shift handle and below the environmental controls of the dash board. I tightly zip tied the microphone clip that came with the FTD onto the ball joint and it holds fast just above and right of my knee while driving. The microphone is out of the way but within easy reach without even a glance, right next to my knee. Low clutter and a clean profile! Because the FTD integrated speaker resides in the chassis stowed under the seat, I included an external speaker that rests nicely in one of the forward console compartment bays. I used an MFJ Clear Tone speaker for its compact size and low price, and it sits nicely in the compartment facing the cabin to provide clear, loud audio.

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There is a serious flaw with the suggestion mobile radios be wired across battery terminals. The negative radio lead should actually not have a fuse, and not be wired to the battery post. Early vehicles had both positive and negative grounds. USA passenger vehicles evolved, standardizing on "12 volt" negative ground systems. The resting voltage was around Many large commercial vehicles, however, retained positive grounds. Non-standardization of systems meant two-way radios and other add on equipment was generally designed to operate with either negative or positive grounds. This was accomplished by floating the internal negative supply buss, while grounding all normally accessible external user ports to the case or cabinet. These early systems started the trend of negative fuses, with both power leads directly attached to the battery. This was not harmful, because the equipment had a completely isolated internal "ground " that was electrically isolated from all other leads leaving the device. Once any other lead common with the negative bus leaves the case, it is no longer safe to conned the negative to the battery post. It is also not safe to fuse the negative lead. In most early CB and commercial two-way radios, the negative buss inside the unit fully floated from the cabinet and any external ports. This included commercial two-way radios like the Motorola Motrac, Micor, and other expensive, high-quality, radios. The floating negative was universal across brands including, but not limited to, GE and RCA land mobile equipment. The floating negative allowed use of radios in either negative or positive ground vehicles. It also solved ground loop issues, allowing direct connection to battery posts without fire or equipment damage hazards. Equipment manufacturers had no way of knowing if the final installation would be in a negative ground vehicle or a positive ground vehicle. As a result, systems with a floating negative buss were shipped with both negative and positive power line fuses. The floating negative buss system inside the radio allowed safe direct connection to the battery posts, and safe shutdown if either the positive or negative fuse opened. The floating negative power buss made it impossible for starter or charging currents to flow through antenna cables, microphone, or speaker leads. All exiting connections, as well as the case, were electrically isolated from the negative lead.

How to Ground an Antenna: aerial earthing

Forgot Password? After antennas, station grounding is probably the most discussed subject in amateur radio and it is also the one replete with the most misconceptions. The first thing to know is that there are three functions served by grounding in ham shacks: 1. Electrical Safety 2. Lightning Protection. Each has it's own set of requirements, but not all station setups need every kind of ground. In fact, some setups don't use a ground at all! The articles on this page will help clear up some of the myths and mystery surrounding this popular topic. How important is a ground? Most people say that grounding is all- important, but I have had a few people tell me that grounds aren't necessary. Grounds fulfill three distinct functions. The best ground for one function isn't necessarily the best for another. The three are:. Safety ground. This protects you from a shock hazard if one of the mains or high voltage power supply wires contacts the chassis due to some kind of fault. The requirements for this ground are spelled out in your state's electrical code. The safety ground conductor in your wall sockets should be connected to ground according to this code, and your rig's chassis should be connected to the safety ground. Lightning ground. The requirements for a ground for lightning protection are much more stringent than for a safety ground. The topic has been discussed in this group many times, and there are numerous resources available for learning how to make a ground system for lightning protection. RF ground. This is required only for certain types of antennas-- ones which require current flow to ground to complete the antenna circuit. An example is a quarter-wave vertical. One wire of the feedline connects to the base of the antenna, and the other connects to ground. The connection to ground has to have a low RF resistance, or you'll expend too much of your power heating the ground. A few radial wires will provide a moderately low loss connection. A ground rod will help a little, but the RF resistance will be high, resulting in quite a bit of loss. If it's longer, you can get by with fewer. The requirements for various other end-fed antennas depend on their length. If you use a "complete" antenna like a dipole or a ground plane that is, one that doesn't require your feedline to connect to groundyou don't need a RF ground, as long as you keep common-mode currents off your feedline. A "current" or "choke" balun is most commonly used for this. I live in an apartment, and I highly doubt I can do this. Shallow-buried radial wires are the best. Connection to other conductors just under the surface, like a metal water pipe, is next.

Mobile antenna grounding

Forums New posts Search forums. Media New media Search media. Classifieds New listings. Log in. Search titles only. Search Advanced search…. New posts. Search forums. For a better experience, please enable JavaScript in your browser before proceeding. Mobile antenna grounding. Status Not open for further replies. I've always heard that "grounding is grounding" except when it comes to lightning but is that always the case when it comes to a normal ham radio antenna setup? I'm wanting to ground my vehicle ham radio antenna to improve 6 meter transmission and transmission. The antenna mounted on a luggage rack crossbar that is painted. Neither the mount nor the antenna is grounded because of that coating on the crossbar. Would it be better to run a ground wire from the antenna mount to a ground point, probably following the same path as the coax, or, would it be permissible to ground the PL connector where it plugs into the radio using a more convenient ground point from inside the vehicle? The radio is mounted under the passenger seat with the control head attached to the side of the side of the console. I have this antenna mounted on a trunk lip mount. It requires a good ground plane to work correctly. That needs to be at the feed point not at the radio. I would suggest looking at a different type of mount. It's pretty long for a luggage rack mount anyway. Do not confuse DC grounding which is best done at the radio with RF grounding which needs to be done at the feed point. You want the car body to be the ground plane. To make this work well sometimes it's necessary to place copper braid between the trunk lid and the car body. You may have to experiment. I've used mine on the low end of the band for sideband, but it's not too efficient for DX. The sound plane is most critical for 6 meters, but also necessary for 2 meters and 70 cm. I understand the necessity for grounding 6 meters. That's why I'm wanting to ground the antenna.

grounding a mobile radio

QRZ Forums. Nothing in the manual says anything about how to ground the radio. I read all over the place that I should ground the radio yet the manufactorer says nothing about how. So how does one ground a mobile radio? If you have connected the black lead to the negative side of the battery and the antenna feed line coax is connected tot he antenna and the antenna is connected to the body of the car, this is usually the only grounds you are going to get. HF rigs have a ground lug. You can take a wire from this ground lug and connect it to the chassis of the car. Sometimes this helps limit or reduce noise. K8YSAug 9, VHF Okay. What about the mobile VHF radio in the house as a base station? My antenna is in the attic and thus not grounded. If your power supply has a lug for ground, ground the power supply via that lug. Word of advice on the mobile. Either run both wires from the battery and fuse them both at the battery, or use the shortest ground lead you possibly can. This is to prevent your radio from becoming the whole car's ground if the body ground wire should come loose under the hood. This is known to happen and is not good, therefore most factory power leads have a fuse on each polarity. I chose to ground my radios with about 10 inches of the ground wire to a body bolt on the passenger seat base. This helps eliminate the resistance of two long skinny wires all the way to the battery. And grounded this way, if the body ground is lost, the radio among other things will act up, but won't become the ground path for the whole car. Low-voltage DC-powered equipment like yours can be totally ground isolated in all ways and function perfectly. There will always be an ESD ground provided by the negative lead that connects to the power supply and its impedance is very low for that application. And for an indoor antenna, a lightning ground isn't a good idea, since it would route lightning energy inside the home, which isn't where you want to conduct it. Show Ignored Content. Share This Page. Your name or email address: Password: Forgot your password? Register for a free QRZ account.

Mobile HF Grounding and RFI

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