Suggestions for FM Antenna Mounting

from what I've heard about antenna mounting, the antenna should definitely be above the metal of your roof (which is probably blocking the stations coming from that direction)

The antenna is mounted to the eave right near the peak of the roof, so nearly all of it is above the roof. I was just wondering if anyone had any experience or knowledge of whether I would gain any range by raising it farther above the roof.

Replace your antenna with a directional YAGI with a rotator such as an APS 9 or 13. Placementment of an omnidirectional is almost an oxymoron if one understands the machinations of FM.

Some basic guidelines that apply to any antenna installation

1) "Height is might". The higher the antenna, the less obstructed the view that it has of incoming signals.

2) Antennas should be mounted away from nearby metalic objects, especially those of the same polarity ( vertical antennas don't like nearby vertical metal objects, horizontal antennas don't like nearby horizontal metal objects, etc... )

3) If an antenna is electrically shortened and makes use of a loading coil, the bottom of the loading coil should be located above the highest point of any support structure. In other words, the loading coil should not be blocked in any direction.

4) Base loaded antennas are the lowest in efficiency. Center loaded antennas are higher in efficiency and top loaded antennas are even more efficient ( comparing apples to apples ). Any antenna that makes use of a loading coil "typically" is of lower performance in terms of incoming signal strength and receiving bandwidth than a larger antenna that does not make use of a loading coil.

As a side note, the Magnum / Metz / Fanfare antennas are base loaded.

5) All antennas work better with a suitable "ground plane" or counterpoise below them. Antennas that do not have ground radials are more sensitive to their surroundings and feedline placement. In such cases, moving the antenna feedline a few feet can sometimes make a very noticeable difference in the quality of received signal.

As a side note, the Magnum / Metz / Fanfare antennas do not have a built in counterpoise. Performance can be improved if you can mount the antenna on a metal support post that is appr 90" - 96" tall. This is not a common length for pre-manufactured pipe or antenna mast, so you might have to cut to length. The support post or "mast" should be electrically coupled ( metal to metal with no insulating paint, etc... ) at the mounting hub of the antenna. If you can keep the mast electrically isolated from other metal where it is supported or mounted at its' base, the FM antenna will now have a tuned counterpoise of appr 3/4 wavelength to work off of. If you can't make use of a support post that long, use something around 30' - 32" long. This is appr 1/4 wavelength and may work "almost" as well.

6) No part of the antenna should be blocked or shielded by nearby metal objects. Mounting the antenna out in the open above all nearby metal objects would be optimum.

As a side note, the Magnum / Metz / Fanfare antennas make use of a metal shield around the loading coil. This is a horrible design and reduces the efficiency of the antenna in every measurable aspect of performance. Pulling the metal "can" around the loading coil at the base and replacing it with a weather-proof non-metalic / non-shielding material will increase the performance of this and any other similarly designed antennas.

7) Signal splitters absolutely kill the performance of any antenna. If at all possible, try to avoid using them. If you must use a splitter, use one splitter and route the cables from that point. One should never route the antenna feedline to a splitter, divide the cables from there, feed another splitter at a different location, etc... Even if it is more convenient and make use of less cable, the amount of signal degradation that takes place is very large. As such, ONE splitter is all that you are allowed, so make sure that you get one with enough taps to do the job. While i don't advise using a splitter with a bunch of extra unused taps on it, those that aren't being used should be terminated with the appropriate plugs. Most all of this stuff can be found at Radio Shack, Best Buy, Circuit City, etc... Bare in mind that there are differences in splitters, so look for one that offers the highest bandwidth possible. These are typically the lowest loss.

8) Vertical omnidirectional antennas can work very well for most applications. If you are in rough terrain, have a lot of nearby structures that block / reflect signal or are a great distance from the stations that you want to receive, some type of directional antenna should be used. If all of the stations that you would like to receive are located in one direction, you can simply orient the antenna in that direction. Otherwise, i would recommend using a rotor. This allows you to point the antenna for optimum signal strength simply by rotating an electrical switchbox mounted near the tuner.

Large directional arrays will always provide the highest signal strength, lowest noise floor, least amount of multipath, etc... but are sometimes overkill if living near a large city. In some cases, one may have to go to a large directional array with a rotor to avoid picking up nearby stations that are causing front end overload i.e. very strong signals swamping the tuner out. In such cases, turning the antenna AWAY from the strong signal may allow you to pick up stations that would otherwise be knocked out of the picture.

9) Never skimp on antenna feedlines. Cable loss can eat up a lot of signal. On top of that, all cables deteriorate with age, especially when exposed to sun, wind, rain, etc... It is better to spend a few dollars more when first installing than to have constant problems or have to replace the cable sooner than normal due to deterioration that has taken place.

10) All outdoor connections should be weather-proofed. The best solution that i've found for this is available from Radio Shack and is called "Coax Seal". It remains pliable, is easily removed, can be re-used and allows basic antenna maintenance without having dig through silicone caulks, etc... It is also far more durable and reliable than electrical tape, duct tape, etc...

Hope this helps... Sean
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