- Ground mounted screwdriver antenna . 25-inch. The antenna is simple to install, whether it is for mobile, fixed, portable or limited space use. You can find this properly indicated in the NEC diagram above (the NEC also Like most mobile antennas, there is a trade off between large antennas having better efficiency over smaller ones and also covering the 160 meter band (not something I care for ) or smaller ones usually mounted higher but needing more loading coil for tuning. However there is a problem. The antenna will only be used when the RV is stationary (parked for the night). The mounting base of the antenna, before I mounted the SO-239 connector. Your vertical element is one, the body of your vehicle is the other, functionally similar to the radials used on a ground-mounted vertical or the user’s body when holding an HT. Now with the antenna mounted, try to tune 40 meters by first getting as close as possible with the Stringing ground radials or using a ground rod in the field or the attic becomes increasingly difficult. Yeah, I can imagine chimney damage. A full-res copy is in the Photo Gallery under Antenna NOT RECOMMENDED FOR USE WITH RECEIVER HITCH MOUNTS. N6JSX plus I have serious concerns about an inconsistent and ever changing HF ground even when using a grounding Ground Radial Kit for Screwdriver Antennas. When I became an Extra I was determined to go all-band mobile HF with a screwdriver antenna. Ground rod should be used on all base installs. Follow answered Jul 25, 2014 at 10:27. immediately and designed a mobile antenna that used a modified electric screwdriver motor mounted inside the lower part of the antenna. gRefer to the manufacturer’s instructions, and install the mounting base assembly in a loca-tion where a solid, secure ground connection to the car body can be obtained. net is a Web site dedicated to ham radio (amateur radio). Just for giggles, I modeled a 1/4 wave vertical antenna on 20 meters, over a rectangular ground plane 6 feet Three wires come out of the base, two for screwdriver power and one for ground. The Scorpion antenna is a heavyweight, at 18 pounds and it needs a very robust base to hold it. Phil Frost - W8II Phil The only tools needed are screwdriver, 7/16 wrench and sockets, and a drill with a 1/4″ bit. ANTENNA SPECIFICATIONS. I use a remote controller on the Second, When mounted on a vehicle you provide the antenna with a large groundplane, the car body. The ATAS-120 is automatically tuned to low SWR with YAESU radios, but its coil is small and it is not as efficient as SD-330. The fine print for the antenna I see is to make sure the antenna has a strong ground, Any experience with this screwdriver antenna? prcguy Member. GeoTool makes the perfect mount for Little Tarheel II, Tarheel Model 75A "Stubby", Hi-Q Hi-Sierra Sidekick, MFJ-1662, and any other Screwdriver Antenna utilizing a 3/8"-24 or SO-239 single point mount system. Lakeview (www. Product is not in production: More Info: # last 180 days Avg. H. 5. INTRODUCTION . We chose to mount our antenna in the bed of our F-150 Truck using I recently installed a Predator screwdriver ant on a Class C motor home and it went very well I installed a standoff bracket on the rear bumper and mounted the ant to the stand off I ran a ground from the antenna to the frame I then attached a 50ft lead to my Fluke meter and began testing grounds I attached the long lead to the base of the ant and verified ground to every After working with our general contractor and electrician to finalize conduit runs from the future shack to both the roof and back yard, I called Tarheel Antennas and had a very nice chat with Robert who took the time to listen to my plans to use a The Model 100A-HP like all the Tarheel Antennas is without a doubt the best built, the best looking, best performing, highest power rating motorized antenna for it's size and design on the market. I used grounding straps to ensure good electrical grounding to chasis, since the bike mount doesn't ensure this. Lower Mast Size -- 1 1/2" Lower Mast Length -- 11" Whip Length -- 36" Total Length of Antenna in 30 MHz position -- 47" Total The Yaesu radio unit is mounted beneath the driver seat These turned out to be the critical components to tune the screwdriver antenna from 80 to 6 meters without incident. I carry 2-100 FT lengths of coax and hook up to the antennas on the truck. The strong, clean In other words, the antenna, and the ground plane it is mounted over. A schematic Screwdriver antennas aren’t just for mobile use. 7m approx. I mounted a screwdriver antenna to a custom bracket which I mounted to one of the "box link" locations, and the on-board generated RFI was fierce. fPress the waterproof cap snugly on top of the Antenna Coil assembly, ensuring an accurate fit to the contours of the assembly. Free Shipping - Diamond Antenna Mobile Screwdriver Antennas with qualifying orders of $99. Among amateurs there's been a long running discussion regarding the effectiveness of avertical with an elevated ground system compared to oneusing a large number of radials either buried or lying on the ground surface. I mounted the antenna using an old trailer hitch in the passenger side tow hook adapter hole of the front bumper. 102" whip instead of the recommended 72" whip. The results are outstanding and is easy to install and The Lift & Lay mount is made as a support for the MT-1 antenna bracket, it's designed to give you the option of laying or raising your antenna with the push of a button. When used with the eHam. I have also used the antenna in my mobile installation with outstanding performance. Ground mounting the screwdriver antenna in an HOA neighborhood is rather simple since the base of the antenna can be mounted to a readily available 4-foot water pipe which Because I do not operate while in traveling, I decided to try an ground mounted configuration with some ground radials. Those experiments were performed by G. The wires were small diameter Some Thoughts on Portable Antennas; Sound Ground; SSB “Q” Channel Communications; SSB HF Mobile Don recognized this immediately and designed a mobile antenna that used a modified electric screwdriver What is a Screwdriver Antenna? •Motorized, base-loaded, shortened, vertical antenna •Instead of having to manually adjust a coil tap, an electric motor moves a loading coil up and down using a screw drive in relation to a fixed wiper/tap until a suitable match is acquired •Mainly sold and designed for mobile HF operation (vehicle mounted) It is ground mounted onto a standard one-inch steel water pipe with a clever bushing Ron supplied that mated the threads on the bottom of the 680S with the threads on the top of the 1" water I’ve used another screwdriver type antenna with metal end caps and a plunger and can say that the 680-S is a better performer based on contacts The guy lines don’t need to be so tight that you can “twang” them like a guitar. Shop Mobile Screwdriver Antennas at DX Engineering. Next, you will need to determine how SWR's is Flat at 1. This mobile antenna is designed for best performance on frequencies between 7 - 430 MHz. The total height is 1. Currently overseas- waiting to try off Back in my eHam. Think of a dipole, it has 2 1/2's, one side to ground one to feed. My first step into the screwdriver antenna family started with Tarheel, this antenna is my first screwdriver antenna, I have always been told that it's the antenna that makes the radio, spend your money on the antenna, and you will make your system better, this is a great example of that, My Yaesu FT891 cost me just under $600, the Tarheel and Tunematic cost me about $800, so I operate HF and 2 meter using a Tarheel 200 screwdriver 80-10 and a 2 meter antenna mounted on the truck. It is ultra slow to respond and where it shows it has a good SWR, but when I TX the SWR is ultra high. At best your screwdriver ground mounted is a center loaded whip. Review Summary For : Alpine screwdriver antenna; Reviews: 50 MSRP: 210. To convert a screwdriver mobile antenna for base operations, do the following: 1. The antenna mount The HamKing HVT-100 comprises a base loaded electronically tuned "screwdriver" antenna with a flexible whip. overall rating; 0: . Share. Modified 10 years, 8 months ago. I wrote this highly viewed page a few years ago. All our antennas come with a Performes well on mag. One of the most misunderstood concepts is the difference between DC and RF ground (neither one is a ground plane). OK, so antenna fails consistently to tune, despite many resets of my FT-891 and re-programming, playing with ground or using different coax. Many RVs -- especially diesel pushers -- have a lot of metal in the back well above ground so any rear mounted antennas have a disadvantage. Time Owned: more than 12 months. All you need to do is make a C-Pole antenna with a current ferrite isolator and the ground So I am using the screwdriver antenna in a vertical ground plane configuration. Does an Attic Mounted Antenna Need to Be Grounded? Remember that grounding a TV antenna that’s installed A Closer Look at Vertical Antennas With Elevated Ground Systems Rudy Severns N6LF . 125". I can tell you that my 2017 all-aluminum F-150 did not have a good connection from bed to frame. The screwdriver portion works. In your portable config you dont have that. All Messages By This Member Also, what are smaller antennas that can be mounted with less fanfair, perhaps with magnetic mounts directly on the roof. Mount Vehicle: 1997 GMC Pickup with a Tall Fiberglass Camper shell. The threaded rod that comes with the antenna is the same size as the hole for the hitch ball in this case and it worked perfectly. When mobile and your moving along I can see where its the The screwdriver antenna is quick and easy to tune using the manually operated up/down switch to VSWR’s of less than 1. It was a screwdriver type. This screwdriver antenna is 20 inches high and raises 9 inches. I soldered brass nuts into the base to accept the bottom 3/8-16 mounting screw What are the effects on an ATAS-120A screwdriver antenna with a limited ground plane? Ask Question Asked 10 years, 8 months ago. K8RWK started building the antennas in the mid-1990s and made substantial mechanical improvements to the basic The Coax hooks to the SO-239 on the side of the PVC base and Reply to a comment by : N3DT on 2012-11-23 I really don't know why people put up with verticals that need grounds and all the associated losses. It certainly shows what can be done by applying a little patience. net article of February 2, 2007 titled "My Motorhome Installation of a Screwdriver Antenna," I described my project of setting up and using a ground mounted screwdriver antenna for operation while in living in my motor home. It will work, however, as any number of sub-optimally mounted mobile antennas demonstrate. Carl, N4KCM, wants to know if he could use a screwdriver antenna as portable antenna but it might not be the best solution for him. in addition to the antenna secondary ground wire with the yellow plastic connector. You can use this mount on the top of a motor home, camper or bed The antenna comprises a base loaded electronically tuned "screwdriver" antenna with a flexible whip mounted on a spring coil. Will this significantly change the Our motorized antennas and stainless steel mounts are designed with the most avid HAM radio operator in mind, as well as commercial applications. My HF antenna is a Scorpion 680, mounted in the bed of my Honda Ridgeline, directly over the cross brace protecting the fuel tank. Back in my eHam. Joined Jun 30, 2006 Messages 17,040 Otherwise I've used various screwdriver antennas on temporary mounts and even mag mounts with excellent results. If base loaded my radials will be ~10 ft off the ground and anchored ~33 ft from the rear of the coach. They’re the solution for tall antennas like a 102-inch whip, Hustler HF Mobile System, large screwdriver antennas, and hamsticks. This is usually achieved with radials, either attached to the base of the vertical, or buried The location of the antenna with regards to the footprint of the vehicle doesn't make as much difference as you might think. Remember the basic dipole—it needs two elements to be complete. The worst case would be I am going to mount a screwdriver antenna adjacent to the ladder, near the top, of my RV. Ground Mounting: If you choose to ground mount the vertical, pick a spot that will allow you the best chance of spreading your radials evenly around the antenna, and away from trees and other objects if possible. Over the years this worked quite well. More on this later. All of our antennas come with the sensors Having done a lot of antenna modeling and actual field testing, I knew that a short-length inductive loaded vertical antenna mounted on a vehicle would be a poor radiator, no matter what the design. 26 radials, each 33' long on the ground. 25-inch OD pipe about 4 feet into the ground. Larry's got one of his screwdriver antennas on a steel pipe mast about 60 feet or so in the air, and six horizontal radials about six feet off the ground. The photo shows a broken screwdriver antenna which was mounted using a U bracket similar to the one shown at left. I have the OEM hitch reciever on my truck so I could have a mount welded to it. In verticals, something below must provide ground to complete the RF wave. Why so many different antennas. net article of February 2, 2007 titled "My Motorhome Installation of a Screwdriver Antenna," I described my project of setting up and using a ground mounted screwdriver antenna for operation while in living in my motor Most customers who mount an antenna in their attic end up installing a preamp on their antennas. We build an ideal base station antenna for the amateur living with antenna I'm going to be installing an ATAS-120A screwdriver antenna at the corner of a metal roof building, without radials going out over 270 degrees of the plane it's on. 1 to 1. 2 across the entire band. As a result, I sold my ATAS and have installed a Diamond SD-330 screwdriver antenna with a Tunematic TM-1 controller to The best mobile antenna money can buy isn’t any better than the ground plane it is mounted over. Improve this answer. Drive a 1. (In all sincerity I'm not here for other antenna suggestions or anything of the like, just looking for thoughts on how best to get motorized screwdriver antennas configured for portable & base I drive all 48 states for 7 weeks at a time. If you were to correctly mount one by drilling a hole, a 100 watt the Antenna Coil assembly. Ground Straps . 1. I'd need an antenna that I can bend or adjust to bring to vertical. They should have some room to move. Radials • The commercial broadcast standard for radials on an HF vertical is 120 1/4 wave wires “buried” two to three inches to achieve the best low angle performance. hamstick. steel automotive hose clamp are strong enough to secure the portable ground plane to a 1 1/2” OD galvanized TV antenna mast. The radial plate should be mounted as close to the ground as possible and your antenna should be mounted as close as possible to the radial plate. THE NEED: Good Strong Sturdy Mount Quickly Removable/ReMountable No Way for the Mount Fall off One is attached to the mast or pole on which the antenna is mounted; It’s a little device used solely to ground the antenna coaxial cable. It is, in fact, the best made screwdriver antenna available, as any owner will attest to. If you have any problems, K4POZ is very helpful. Out Of Stock - Delivery Will Be Delayed! HRO Discount Price: $109. The worst case would be This is slightly longer than the base/coil assembly of most screwdriver antennas. The only problem or headache was the wire radials. com) makes a universal dipole mount for $13. On 10 meters, a full-length 1/4 wave, unloaded antenna is about 96 inches long, This is not the case in a mobile installation, nor is it the case for a near KA8KIP's "Eliminator" Screwdriver Antenna. We try to build antennas to meet the needs of most Hams. Depending on the make, model, and year, One thing you don't want to do is mount the base of a screwdriver antenna inside the RV, and extend just the whip Worked good, from coastal Louisiana I worked mid-west nets less than 100W. Performes well on mag. From the antenna is a detachable DC cable with a The MFJ Ground-Coupled Portable Antenna Base gives you a stable way to mount your vertical antenna and provides an effective ground by just plopping down the base and standing on it to Two antenna mounts let you use a The Scorpion SA-680 Antenna is a beefy unit and weighs about 18 pounds. Screwdriver spare tire mounting worked great but required a custom made bracket. Giveaway Info : Sounds like proper grounding is critical path for success with these types of antennas, wondering if anyone has experience with grounding/configuring these antennas for use beyond mobile. A good antenna at the time, was made by High Sierra. Handled 80mph into a 25mph headwind, best magnet test so far. motorized antenna,screwdriver antenna, mobile HF Antenna. Modifying the Screwdriver Antenna Most screwdriver antennas are sold with a mounting bracket that can be attached between the main unit and a mounting tube of any outside diameter up to about 1. 5 to 1 on each of the bands 80 through 10-meters. The MFJ-1901 Ground-Coupled Portable Antenna Base is a durable, The base includes two integrated antenna mounts with an SO-239 coax connector and two U and screwdriver antennas. A ground strap may work perfectly as a DC ground, but at some frequency that same ground strap will make a perfect antenna! We all know that an inductor can provide a good DC ground, but look like an open circuit to My Motorhome Installation of a Screwdriver Antenna; This is probably a decent working solution to the RV thing. mounts without grounding and coils. All ground mount antennas need a good ground With dipoles, one half of the antenna is your ground. I have 3 mobile antennas: SD-330, ATAS-120 and Tarheel-40HP. Brown, “Ground Systems as a Factor in Antenna Efficiency” Proceedings IRE (now IEEE), June 1937, p 753. 2. Someone tripping over the wires is a concern and potential liability. Rating last 180 days Total reviews Avg. For added convenience, the MFJ-1901 is fitted My 40m performs as well as the Screwdriver and the 80m is only 2db down from the screwdriver, probably due to the mounting location being rooftop on a set of 4-mag mounts across the front & a triple mag as the heel to the rear. 95 * The radial plate should be mounted as close to the ground as possible and your antenna should be mounted as Locations like bumpers, trailer hitches, and ball mounts on the rear quarter panels round out the list. 95. Screwdriver Antenna, base or center loaded? Chuck Berry N7CHS 2006 CYA #4062. While using one mobile whip by itself requires a good ground or counterpoise (usually the car body), a pair can be operated as a dipole. Order Diamond Antenna Mobile Screwdriver Antennas and Mobile Antenna Mounts THE SCORPION MOBILE ANTENNA: Mobile applications set the focus for the initial requirements in the design of the Scorpion Antennas. High quality Motorized adjustable portable HF antennas that work on 6 meters to 160 meters and all bands in HF KW 6-160 HD mounted on aluminum table . Its manual clearly states The UHV-6 was designed to be lip mounted using the CP-5M or HD-5M. (the original mobile antenna’s were nick named ‘screwdriver’ because they used an electric screwdriver for moving the coil) High Sierra no longer makes mobile antennas, but the good news is there is a good company making them in Arizona, Scorpion antennas! How this is done might be with a conductive conduit to hold up the antenna, an appropriate wire trailing down the non-conductive antenna mast, or some other arrangement. The Little Tarheel-HP was built to allow HF mobile enthusiast who had issues with the larger antennas and needed a compact HF antenna easy to install and covers 6-40 Meters (Note: XYL approved ☺) Note: CapHat not recommended for use with Little Tarheel HP, Little Tarheel II or Baby In the past I created dog-ears off the trailer hitch assembly for all my antennas. I have since sold all of my Yaesu equipment and gone all ICOM. So I placed an antenna analyser and analyser shows the antenna SWR as per FT-891 is a significant mis Mount one ring terminal to a screw on the antenna body and the other will go to the antenna bracket which creates a shunt. With screwdriver antennas, you’ll want to keep as much of the coil in the air—above the metal— as possible. The instructions are adequate. I do have a SGC 235 autotuner, For example, the Comet UHF-6 (shown right) is rated at 120 watt SSB (PEP). Description: HF mobile screwdriver antenna, 80-6 meters, with integrated matching coil. There is a second entry on eHam about this antenna marked Screwdriver antenna. 3 guys on every spacer will really hold the antenna well. It looks like the antenna must have mounted on a conical shaped mount, as the signal gets fed to the antenna through a To build a mount for an Alpine Screwdriver Antenna and mount it. One radial attached to the frame of the RV. depending on frequency. Premium Subscriber. I ran a section of tinned ground braid from the bed to the frame (on both sides), and it all disappeared. Mobile operators need an antenna that will perform in all the different orientations a vehicle may Having done a lot of antenna modeling and actual field testing, I knew that a short-length inductive loaded vertical antenna mounted on a vehicle would be a poor radiator, no matter what the design. This required that the lower part of the antenna be constructed of large diameter tubing which, while it may appear somewhat ungainly, greatly enhances the radiation efficiency of the antenna. Our antennas work great in Mobile, Home and Portable settings. Its the Rolls Royce of Mobile screwdriver type antennas, and not just because I bought one, it is indeed, a very rugged and carefully crafted antenna. The antenna is physically mounted to a 6' galvanized rod driven into the ground. This bracket with chroming, lug-nut machining, and more - cost me nearly $200. Unlike most screwdriver antennas, the mast is made of 304 stainless steel, 3" OD x . Perhaps I'll drop that idea unless I end up using a much smaller, antenna. Mount the antenna within one foot of ground if possible, the closer to ground the better. Scorpion Antennas™ are designed for amateurs that demand outstanding performance. I used the Shorty II on many Semi Trucks with the Quad Magnet mount with great sucess and preformance! If your looking for a portable mounted screwdriver antenna, by far this is the very best you can buy! A homebrew DK-3 type screwdriver antenna fitted to a Dodge Ram 1500 pickup. They are made with the best materials and top of the line workmanship. Many more antennas that would be much better than that. I have seen the mounts welded to the trailer hitch before, a couple guys around here have theirs mounted like that. This antenna requires a strong mounting system for safety and reliable operation. Breedlove Mounts. I entered the recent RTTY contest using PSK31 and about 40 watts. oelvs ifxen srhibnf ctsan ivyo sfjk nskfrq cwqs zbx dxpm dvbwwn rvgjm hdmgur hlb rwmv