Outdoor FM Antenna OMNIDIRECTIONAL

4/6/25I live in rural SE Arizona, where stations are typically low-power and on the other side of some mountain. With this antenna mounted 25 feet above ground level, and a Denon receiver, I can receive quite a few stations, including five or so that I like some of the time, one of which is 75 miles away and has a signal strength of -103 dBm at my antenna, according to FM Fool. But it's not very clean, and a preamp would probably help.There's no need for an expensive, super-low-noise preamp specifically for FM, since the typical VHF/UHF preamp these days has a noise figure of less than 3dB (i.e. above atmospheric thermal noise, which is very low), and that's for a 6 MHz bandwidth. Each FM channel has a 200 kHz bandwidth, or 1/30th that of a TV channel, which would reduce the preamp's noise figure for FM.The preamp would require low-VHF coverage and couldn't have an FM trap, unless it could be switched off. Overloading the tuner's input, which has to be evaluated on a case-by-case basis, doesn't seem to be a concern when using a preamp in my situation.Some FM-DX experts recommend the Winegard LNA-200, which has a noise figure of less than 1 dB. The RCA 2450 VHF/UHF preamp with a switchable FM trap is another option. Its noise figure isn't specified, other than "very low." I've been using an earlier model (TVPRAMP1R) for years to receive some very weak TV signals, but they're digital with built-in error-correction capability, so that even if they're barely detectable, the audio and video are as good as if the signal were strong. ATSC 3.0 will include radio stations, but in a lossy format. I'm waiting for QDEL/nano-LED technology before upgrading to an ATSC 3.0 set.According to a page which can be found by Googling "RCA TVPRAMP1R Amplifier - TV Fool" (include the quotes), the TVPRAMP1R has a noise figure of between 2.6 and 3.9 dB, depending on the frequency. But this is for a 6 MHz bandwidth (TV channel bandwidth), whereas an FM channel has a 200 kHz bandwidth, which is 1/30th that of a TV channel. The atmosphere's thermal noise for a 6 MHz bandwidth is -106 dBm, whereas for an FM channel it's -120 dBm, which might mean that the RCA's noise figure for an FM channel could be very low. But there isn't a simple conversion factor, because the types of modulation have to be taken into consideration.But because the atmospheric thermal noise is -120 dBm for FM channels, even -100 dBm FM signals should have a good carrier-to-noise ratio, and my tuner should be able to extract clean audio from them if they're boosted by about 20 dB. As mentioned above, it does a tolerable job of detecting a supposed -103 dBm signal (KHYT Tucson) even without a preamp. So, I'll probably try the RCA and revise this review with my findings.Running the antenna cable through the wallI needed to run the antenna cable (RG6, with a compression connector attached) through an exterior wall of a mobile home consisting of thin paneling on the inside, studs spaced 16" apart, fiberglass insulation, and a masonite exterior panel. This required a tube to guide the cable. I ended up using 1/2" conduit (slightly more than 1/2" ID), which required a 3/4" hole. I anchored it with a P-clamp, a short 1/4" bolt, and a link of double-link-chain (see photo). To cut this type of chain, I use Greenlee 722 shear-type wire cutters. Tape can be applied to the conduit to give the clamp a better grip.First, I drilled a 3/16" pilot hole through the inside panel into the stud, and then fastened the anchor to the wall with a 1/4x1.75" lag screw. I then inserted a 3/4" wood bit into the pipe clamp to mark the center of the 3/4" hole. When this is being done, the bolt and lag screw should be centered lengthwise in the chain links, to provide some wiggle-room for error.To get the outside hole lined up with the inside hole, I used the stud and a horizontal window sill as references. I had to put some small blocks of plywood on the window sill to obtain a reference that I could use both on the inside and outside.On the outside, I put a piece of 1/4" fuel hose, slit lengthwise with pointy scissors, over the RG6 to protect it from the conduit's edge and to prevent the cable from bending sharply at that point, where the tendency for doing so is greatest. I also cut up a cat food can with tin snips, although scissors might suffice, to create a "hood" to prevent rain from running down the wall and getting into the hole. I taped it on with white Gorilla tape, although roofing tape would be better.

Works very well. Helped eliminate static and pick up radio stations we weren't able to get before.

Kind of cheaply made but if you secure properly, you will have no issues. Any gain in signal is a good thing and would buy again.

WOW, Great reception. I live in the country up on a hill. I can get several more stations and all are crystal clear. Even the stations I was getting with a small wire antenna, now they come in in full stereo.

Having been an Amateur Radio (HAM) operator since 1954, I have had a lot of experience with antennas, both commercial and home-made.This antenna is simple a folded dipole that is wrapped around in a circle. Hams call this type of antenna a "Halo" antenna. We most commonly use these on the 6-Meter band. In the '60's, they were quite popular for mobile operating setups.While a straight folded dipole is bi-directional with the maximum signal pickup being at with angles to the antenna arms, wrapping the antenna into a Halo configuration pretty much creates a circular reception pattern. In my case, with FM stations surrounding me by 360 degrees, that's what I need.Testing with my spectrum analyzer shows that, as expected for this type of antenna, the pattern of the antenna is not quite circular but is slightly dumbell shaped, with the ends of the dumbell (best signal pickup) being pointed directly along the metal support bracket of the antenna.If you want the maximum signal pickup from a particular station, point the end of the antenna that has the coaxial cable connection box in the direction of the station. This will give got a slight signal increase of about 4 dB. Note that the weakest signal pickup directions will be at right angles to this pointing direction. But, in any case, modern FM receivers are so sensitive that I doubt you will be able to tell the difference unless the signal is so weak that is noisy.In the attached photos, the direction of maximum pickup is towards the right of the antenna, in the same direction that the parabolic antenna is pointed.As for construction quality, the aluminum tube used for the antenna is reasonably thick and quite stiff so it should retain its shape through the years. If you mount the antenna so the coaxial connector is facing downward, then the four small weep holes in the bottom of the plastic case will let any water condensation escape to prevent corrosion of the matching transformer that is enclosed in the box.A nice touch is the inclusion of a black soft plastic boot to cover the coaxial cable connector where it attaches to the antenna. Be sure to slip the cover over the end of the coax cable BEFORE you install the connector because you will not be able to install it after the connector is crimped on the cable.After you tighten up the coax connector on the antenna, the boot may be slid up the coax cable and over the connector. The boot then slides nicely into a ring-shaped recess under the bottom of the plastic box. This forms a shield that will prevent wind-driven rain from getting to the connector and eventually wicking into the coax cable. Water and coax cables are a bad mix, because the water will cause a high signal loss.So I am well pleased with this antenna, and think that is worth it for the modest price. I am now able to receive FM stations from as far distant as 90 miles, depending on weather conditions.I almost forgot, got to fmfool dot com to get your own reception map for the FM stations at your location.Happy listening!