A.} There is a new page on our web site, appropriately named “fabrication”. It shows some of the methods used to manufacture the portable antenna mount. A direct link to the fabrication page.
Q.} Why is the hole where the locking pin goes through is a bit larger than the pin itself?
A.} We have found vast differences in the location of the lock pin hole in the various receiver hitches we have tested. To remedy these situations a much larger hole in the antenna mount was made to allow the antenna mount to fit without any need for modifying the mount lock pin hole. The pins supplied with our portable antenna mounts are industry standard and will fit your receiver-hitch.Q.} Must I use radials with my portable antenna?
A.} Naturally you must first consider the type of antenna you will deploy using the Tilt-N-Raise™ portable antenna mount. If you are using a dipole or loop antenna then you would have no need for radials. Some commercially produced vertical antennas do not require radials according to their manufacturers. In these cases you should follow the antenna manufacturer’s requirements regarding the use of radials. Some commercial verticals and a good many homebrew vertical antennas do require radials and so you will be able to make use of the radial plate. Should you deploy a variety of antenna types during your portable operations then we suggest you purchase the model with the radial plate attachment. As for the ongoing discussions among radio amateurs concerning the use of radials with vertical antennas it is suggested you read the article by well-known antenna expert Lew McCoy elsewhere in this document.Q.} Can the Tilt-N-Raise™ portable antenna mount be used in a mobile environment?
A.} While it would seem the Tilt-N-Raise™ would make a great mobile antenna mount we discourage its use while the vehicle is in motion. The antenna mount itself is more than adequate for mobile operation but the likelihood of striking overhead objects is too great to recommend you use the antenna mount while mobile.
Q.} What is the maximum height of an antenna and mast that can be used with the Tilt-N-Raise™.
A.} Our suggested maximum antenna/support mast height is 25 feet. Once you exceed this height you place a heavy load upon the antenna mount due to the leverage action against the mount. Therefore you should guy anything and everything over 25 feet without exception (a quarter wave vertical for 7.225mhz is only 32.39 feet). Using guys as standard operating procedures will protect bystanders, your vehicle and your antenna especially for operators who deploy portable stations for lighthouse activations. Lighthouse activators experience higher wind loads than most portable operators due to their close proximity to the shorelines.
Q.} How can I route the feedline/coax?
A.} Since we don’t provide the supporting mast we can’t really answer this question adequately. Some suggestions could be to use Velcro strips to secure the feedline to the mast. Velcro would be better than tie-wraps as they are reusable and can be removed faster should the antenna need to be removed quickly. Also, antenna feed points would play a big part in the routing of the feedline. If you have diagrams or photos of different methods of attaching feedlines during portable operations then please feel free to forward them to us and we will post them on our web site for all to use.
FAQs revised November 24, 2010
Here is some concerns raised by one operator regarding the mounts we manufacture:
Q.} Use of the provided radial connection points (4) is questionable since they are dc-isolated from the entire fixture and antenna extension mast tube.
A.} One look at the manual included with our mounts and you would see that no attempts were made to address antenna theory in the 7 shorts pages. However, common sense would tell you that the radials should be connected to a good earth ground and this issue is covered further in the next section.
Q.} The antenna extension mast is dc-isolated from the entire fixture, and radial connection points, by virtue of the PVC lining inside the fixture.
A.} The mount was designed so that the antenna was isolated from the mount by design, the radial concerns are addressed above.
Q.} These connections are also of very questionable use if a resin/fibre-glass mast is to be utilized.
A.} This type of mast would be isolated no matter the design of the mount due to the nature of the materials used to make the (non-conducting) masts. This would be true whether or not the PVC tube is used or whether the aluminum was powdercoated or not.
Q.} Use of the provided grounding lug is questionable since the lug is dc-isolated from the extension mast tube, and vice versa, by virtue of the PVC lining inside the fixture.
A.} The ground lug was not designed to ground the antenna mast, on our “about” page is this statement:
“As for a good ground for the mount, you can use the grounding lug at the lower gusset support of the mount to connect a ground wire to whatever ground rod you use when operating portable. Do not assume the antenna mount will provide any sort of grounding to the vehicle as it is highly unlikely with the amount of powdercoating applied to the mount.”
Without going too deep into antenna design, good grounding practices and so forth it would seem simplistic to just state that one should ground everything and not depend on metal-to-metal contact as a ground. Without laying out specific instructions about how one should ground their systems when using the Tilt-N-Raise portable antenna mount it would seem elementary that something similar to the following:
A ground rod of at least 4 feet of copper clad material should be driven into the ground close to the Tilt-N-Raise mount. This type of ground rod may not be considered optimal but could serve as a minimum requirement for a ground rod.
An adequate connecting cable should be used to connect the ground rod to the Tilt-N-Raise mount.
A separate wire should be routed from the ground lug on the Tilt-N-Raise mount to base of the support mast if it is metallic in construction. Resin or fiberglass masts would not require grounding due to the insulating qualities of the materials used.
If the Tilt-N-Raise mount is ordered with the radial plate then another ground wire should be connected from one of the radial lugs to the grounding lug of the Tilt-N-Raise mount.
The grounding lug is more of a mechanical convenience for the attachment of the ground wires needed for the Tilt-N-Raise mount.
The DX Zone has some excellent resources about grounding for your amateur radio systems: http://www.dxzone.com/catalog/Technical_Reference/Grounding/
Q.} This connection is also of very questionable use if a resin/fibre-glass mast is to be used.
A.} Once again grounding is mentioned while referring to non-conducting antenna masts. If the mount was bare metal and no PVC tubing was used there would still be an isolation issue because of the nature of resin & fiberglas to be isolators instead of conductors.
Q.} If a steel extension mast of 1.5 inch diameter or less is utilized, and there happens to be a moderate to strong wind condition existing, any extension mast and attached antenna(s) will probably vibrate causing transmit signal distortion for VHF/UHF frequencies. If the antenna(s) are directional yagi’s, utilizing a rotator unit, radial bearings will probably not be stable. Some sort of stabilizing set-screw arrangement, utilizing three or four set-screws, is recommended for the antenna tube of the fixture. The set-screws would have to extend entirely through the PVC lining, obviously. If a resin/fibre-glass extension mast were utilized, the comments about yagi’s and rotators would probably be up for further consideration.
A.} The use of an antenna mast that is 1/2″ smaller in diameter than the mast that the Tilt-N-Raise mount was designed for is not recommended. If you use a smaller mast then you would expect to experience not just “irradiation’ but all out movement of the mast inside of the PVC tubing. Drilling holes into the vertical support tube (or any other part of the Tilt-N-Raise mount) will void the warranty without exception.