EV's Best Top Rated FM and HD Radio Antenna Guide & Reviews

EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#61
Here is some fantastic information posted on the fmtunerinfo.com website....

Paul's Antenna Attic

Below is a listing of antenna specs as published by the manufacturers. Many antenna manufacturers have been known to stretch the truth in their claims, so please note that TIC does not vouch for the accuracy of any of this information. Thanks to our contributor Paul Baptista for compiling it. A word from Paul: "The purpose of this page is not to start a debate on the individual specs unless someone has the equipment to measure them on a purchased unit. My intent was to scan the market and provide what is out there in a catalog format. I left out the prices on purpose so folks can do that on their own." Worthwhile comments from contributors, as we receive them, will appear below the table. Scroll down for some commentary on indoor FM antennas.

This link to our contributor Brian Beezley's antenna page deserves to go above the table. Brian used a computer modeling program to calculate performance results for many FM antennas and compares them to the manufacturers' specs to separate the contenders from the pretenders!


Omni

Antennacraft/RS FMSS/15-216 = 8dB F/B 54" Long
Magnum Dynalab ST-2 = 54" Long
Fanfare FM-2G = 56" Long


2 Elements

Triax FM 2 (100161) = 2dB Gain 10dB F/B
Blake ? = 3dBd/5.2dBi 10dB F/B


3 Elements

Triax FM 3 (100162) = 6 dB Gain 16 dB F/B
Blake 35dBd/7.2dBi Gain 15 dB F/B
Antiference FM1083 = 5dBd/7.15dBi Gain 15 dB 860 mm Long
Matchmaster FM3 = 5dB Gain 15dB F/B
Televes 1027 = 6dB Gain 18dB F/B
Lincrad 502 = 7dB Gain 105cm 168cm Long


4 Elements

Winegard PR-6000 = 5dB 6db to 16dB F/B 33" Long
NilJon HD FM H4 = 9.9 to 10.2 db Gain
Triax FM 4 (100163) = 7dB Gain 18dB F/B
Blake 4? = 6 dBd/8.2dBi Gain 19dB F/B


5 Elements

Triax FM 5 (100164) = 8dB Gain 20dB F/B
Triax FM 5 Split beam (100184) = 8dB Gain 20dB F/B
Antiference FM 1085 = 6.9dBd/9dBi Gain 16dB F/B 20.5cm Long
Televes 1029 = 9dB Gain 22dB F/B
Lincrad 503 = 9dB Gain 257cm Long


6 Elements

Antennacraft/Radio Shack FM-6/15-2163 = 6dB Gain 23dB F/B 70" Long
Magnum Dynalab MD-6 = 8dB Gain 13dB F/B 94" Long
Maxview NB01 = 6.7dB Gain 18dB F/B
Blake 6? = 8dBd/10.2dBi Gain 19dB F/B
Lincrad 516 = 10dB Gain 308.5 cm Long


8 Elements

Triax FM 8S (100197) = 9.5dB Gain 24dB F/B
Blake 8? = 9dBd/11.2dBi Gain 23dB F/B
Matchmaster FMG8 = 10.9 dB Gain 20.5 dB F/B


9 Elements

APS-9B = 7.5 dBd Gain 28.8 dB F/B 100" Long
Delhi QFM-9


10 Elements

Magnum Dynalab MD-10 = 12 dB Gain 15 dB F/B 142" Long
Winegard HD-6065P = 9.4 to 10.6 dB Gain 18 to 20 dB F/B 127" Long


13 Elements

APS-13 = 10 dBd Gain 30 dB F/B 200" Long

Our contributor Hank comments, "Having used both the Winegard HD6065P and the APS-9, I found both to be very good antennas. I noticed no demonstrable improvement in the number of stations I could receive when I switched from the APS-9 to the HD6065P, in spite of the fact that the Winegard is significantly larger. In my opinion, most anyone would be very pleased with either antenna.That said, when I then progressed to the APS-13 (which is what I now use), every important spec seemed to get better. More gain, much improved directionality, *definitely* superior front-to-back ratio. In any situation in which an admittedly rather large antenna is feasible, I'd go with the APS-13."
 
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EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#62
Here is more from fmtunerinfo.com

Paul's Antenna Attic


Indoor Antennas

Our contributor Eli reports on the BIC Beam Box, Model FM10: "I have an FM10 that I just got from Glenn Davis (thanks Glenn!). There is a four-position direction switch on the front, so I assume there are strong nulls at 90 degrees to the selected direction, but I wonder about any backlobes to the chosen direction. My impression (not backed up by any rigorous testing) is that the Beam Box is not completely bipolar (like a dipole) but gives its strongest response in one direction. For those who are curious, there is a tuning knob on the front panel and a 4-gang variable capacitor inside the FM10. This cap needs the grounding contacts deoxidized just like the variable cap inside your analog tuner. I assume that the Wide-Narrow switch on the front panel engages either 2 gangs (for Wide) or all 4 (for Narrow). I didn't actually trace the circuit to determine if this is what the Wide/Narrow switch does - I just made that assumption based on a quick look at the innards. In my playing around, so far, the Narrow position always gives better results. I get a stronger signal using Narrow than using Wide, so any of the differences you would expect from a stronger signal will apply (less noise, etc.). Otherwise, I'm not aware of any sonic differences."

Our contributor John L. adds: "I did a quick, simple directionality test of a BIC Beam Box FM10, a Godar FM1A and a Radio Shack rabbit ears with the ears horizontal. The tuner used is a Denon TU-767 with a 7-segment signal strength indicator. The IF band switch was in the wide position. I connected the antennas to the tuner one by one using the same six foot long coax cable. I oriented each antenna to give the maximum signal strength, which was the same direction for each; rotated it 90 degrees and recorded the signal strength; and rotated it another 90 degrees and recorded the signal strength. The weather was overcast and rainy. The station tuned to is WBGO, 88.3, which broadcasts from Newark, NJ. I was in my fourth-floor Manhattan apartment, which does not have line of sight to Newark and is in a high RF, high multipath environment. The BIC FM10 lit 4 segments max, 3 segments with a lot of background hiss at 90 degrees, and 3 segments with less hiss at 180 degrees. The Godar lit 5 segments max, 4 segments at 90 degrees, and 4 segments at 180 degrees. The Radio Shack rabbit ears lit 6 segments (with the 7th flickering) max, 6 segments at 90 degrees, and 5 segments at 180 degrees.

My reception of WBGO often includes annoying background hiss. The FM10, despite delivering less signal strength, usually reduces background hiss compared to the other antennas. This wasn't the case in this instance as the only hiss noticed was as mentioned for the FM10. The Denon does not have high blend and does not automatically switch to mono at low signal strength. For some stations I get better reception with the FM10 in the wide band position and some are better in the narrow band position. My experience is that indoor antenna reception depends on each particular situation. The only way to determine how an antenna works in your situation is to buy 'em and try 'em."

Here's a follow-up test by John using a fourth antenna: "The additional antenna is a Radio Shack compact indoor, catalog number 15-1843, which is a 5" by 5" by 1/4" plastic-encased square with an integral six-foot coax cable and 75 Ohm connector. It is supposed to be directional when upright with the 5" by 5" face vertical and pointed towards the signal source, and omnidirectional when the 5" by 5" face is horizontal. It was tucked away in a drawer and I had forgotten about it. The weather was clear. No matter which position I put the RS compact in, facing the max signal strength direction of the other antennas, rotated 90 degrees from that direction, rotated 180 degrees from that direction or horizontal, it lit 5 segments on the Denon signal strength meter when tuned to WBGO.

Since the weather had changed, I checked reception with the other antennas. The Godar lit 4 segments (with the 5th segment flickering) max, 4 segments at 90 degrees from max and 4 segments at 180 degrees from max. The Radio Shack rabbit ears lit 7 segments max, 6 segments at 90 degrees and 6 segments at 180 degrees. The BIC FM10 lit 4 segments max, 3 segments at 90 degrees and 3 segments at 180 degrees. At the max position, there was noticable hiss for each antenna except for the FM10 in the wide band position, which had barely audible hiss. In the narrow band position, the FM10 had as much hiss as the the other antennas. Each antenna occupied the same position while being tested and was then removed and replaced with the next."

John compares the FM10 to its lesser sibling, the FM8: "The FM10 has both 300 Ohm and 75 Ohm outputs and generally goes for about $50 plus shipping on eBay. The FM8 has a 300 Ohm output, is otherwise functionally the same as the FM10, and generally sells on eBay for about half of what the FM10 does." Our panelist Eric used an FM8 decades before TIC existed and found it to be somewhat directional; however, it had so much less gain (really, more signal loss) than any generic rabbit ears, it rarely made sense to use the FM8 except for very strong signals with extreme multipath.

And here's Eli again: "I did a little more testing (though not as rigorous as what John described). Using my Yamaha TX-1000, which has an A-B antenna switch, I compared the FM10 to the wire dipole on a wooden "T". The cross-member of the "T" is about 2.5 feet above the level of the FM10, so it has a bit of an advantage. The dipole was connected to the antenna input using a very cheap slip-on 300-75 Ohm balun right at the tuner's input. The FM10 was connected using the 75 Ohm ouput from the antenna and a 1/2 meter coax cable. So, some differences may be due to non-ideal impedance matching or the difference in height. The TX-1000 has a 24-segment "Signal Quality" meter calibrated from 0-100 (the best tuning meter I've ever encountered).

The FM10 is somewhat directional. One of the four directional positions is always stronger than the others. When the four-position switch on the FM10 is set to the position giving the strongest signal, the wire dipole consistently reads twice as high as the FM10 on the TX-1000's meter (if the FM10 shows "20", the dipole shows "40"). Although I don't consider the question completely closed, at this point I would say the FM10 is a good choice only for those in high-signal-strength, high-multipath environments. And then, only recommended when rabbit ears can't be used for some reason."

Here are the FM8's specs (thanks John):

The Beam Box FM8 electronically directable FM antenna

Frequency range: 88 MHz to 108 MHz.
Antenna Gain: - 7 dB typ. (narrowband), - 14 dB typ. (broadband).
Directivity: Four selectable electronically oriented "figure-8" patterns.
Receiving Elements: Four 8th-wavelength aluminium elements.
Circuitry: Two orthogonal, capacitively loaded, foreshortened dipoles with tuned connecting circuit.
Broadband mode: directly coupled with antenna arms.
Narrowband mode: decoupled by impedance matching capacitors through 4- gang variable capacitor.
Controls: Electronic orientation (4-position), bandwith (broad/narrow), tuning (continiously variable, 88 MHz to 108 MHz)
Output impedance: 300 ohm balanced - for 75 Ohm operation external balun transformer with coaxial connector and cable required.
Standing Wave Ratio (VSWR): Less than 1.7 to 1 (narrowband)
Bandwith: in Narrow-Bandwith position 3 MHz typ. @ - 3 dB points.

Mechanical specifications:
Dimensions: 12-7/8" wide, 14" deep, 3-1/2" high.
Net Weight: 7 lbs (3.2 kg)
 
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O-O

DTVUSA Member
#64
Then freakin hit the Thanks or Repuation button. Buttons talk and chatter walks, LOL....

Sorry I had to be obnoxious.... You know we both have reputations to maintain!
:cheer2::cheer2::cheer2::cheer2::cheer2:
it's good to see you eggheads have some humor every once in a while in here. :becky:
 

Piggie

Super Moderator
#66
Just build it yourself! 3 to 6 element FM Yagi

While this is a narrow band yagi, it actually should work across most of the band since it uses a folded dipole for a driven element.

You need twin lead, wire, wood and glue. Paint it makes it weather proof.

3 Element Yagi

don't miss the dimension page where you can add up to 6 elements.
Dimension_Table

Build your own FM6.....

=======

You can use this for High Band Yagi's also. Know that High Band is the second harmonic of the FM band (yes they did that on purpose and not to force us to use FM traps but to keep harmonics off more "critical" frequencies. You will find that true of the ham bands are harmonics of each other.)

Knowing it's the 2nd harmonic, find the TV channels center frequency here.
TV channel frequencies

Then divide the center frequency of the TV channel by 2.

Then look up that frequency on the FM table. Use their dimensions but divide them by 2 also and you have a Single channel 6 element TV high band antenna!
 

EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#67
Im looking into the UK market to add to the guide. There offerings seem a little more varied....like I guess they once were in the US.

Here is a sampling...

Triax FM 3



3-element directional
- Unique Trumatch dipole
- Easy assembly
- Fold down into compact pack

This three element aerial has been specifically designed to work in the FM stereo band 88-108MHz. Ruggedly constructed with the unique Trumatch dipole with parallel resonance properties to give a virtually flat response across the whole FM band.

Forward Gain: 7.2dBi
Front To Back Ratio: 15dBi
Acceptance Angle deg +/-: 32 Degrees
Windage: 67N
Length: 860mm

Antifeference Omni FM Aerial



- The 'Allrounder' omnidirectional
- Easy assembly
- Fold down into compact pack

Forward Gain: 0dBi
Front To Back Ratio: 0dB
Acceptance Angle deg +/-: 180 Degrees
Windage: 14N
Length: 510mm

TRIAX FM 5



TRIAX band II aerials are wide band aerials covering the entire frequency range from 87 to 108 MHz. Band II aerials are provided with a light-alloy metal boom made of 18 x 18mm square tubes. The dipole and the elements are made of Ø12 mm tube provided with strings to damp vibrations and to prevent element resonance.

The FM 5 is provided with brackets for aerial masts up to Ø60 mm.

Gain: 8.0dB
Band: 87-108MHz
Front/Back: >20dB
Return Loss: >15dB
Windload (N): 80
Beamwidth: +/- 27 degrees
Balun: 75ohm
 
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EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#68
Thanks Piggie. My antenna building skills are increasing exponentially. I think Im going to try one of those 1/4 wave a side squre loops, I posted on the previous page. Maybe with some copper tubing of quarter to half inch in diameter.
 
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Piggie

Super Moderator
#69
Thanks Piggie. My antenna building skills are increasing exponentially. I think Im going to try one of those 1/4 wave a side squre loops, I posted on the previous page. Maybe with some copper tubing of quarter to half inch in diameter.
Quad loops are great antennas and are slightly lower noise floor than a dipole, plus about 2 db (dog biscuits) more gain than a dipole.

Actually the quad should be feed with a 1:1 balun. These are next to impossible to find for 100 MHz. I can probably do a search and find one you could build. However you can build a choke easy enough. Wrap about 6 to 8 turns of coax right at the feed point and just use electrical tape to hold the loop. This will stop most current on shield of the coax and make a better pattern.
 
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Piggie

Super Moderator
#71
While the loop only has about 1.15 db gain over a 1/2 wave (which is a great FM antenna to itself). It will appear to have much more. But this time not due to lower angle of radiation, but noise floor. The full wave loop intercepts the magnetic flux of the EM Wave and not the electrical. Think of a quad loop as one turn transformer if you have a hard time visualizing this reception. (but don't confuse folded dipoles that are still dipoles and intersect and receive the electric field of the EM wave just like a plain dipole).

Now that said. Nearly all electrical interference is vertical.

so now we have 20 db down on electrical noise and not sure how much down due to it being an magnetic antenna.

But the result is a much lower noise floor. So you appear to gain more than 2 db over a quaterwave and more than 1.15 over a halfwave.

Then combine that with some FM stations only transmit horizontal and a vertical is right off the bat 20 db down, except for receiving mulitpath that may have twisted it's polarization.

If the station is elliptical generally the two foci are horizontal creating a stronger wave if detected by a horizontal antenna than similar antenna vertical. Even if the station is purely circular (one foci like a circle) then a plane polarized antenna is only 3db down. However since a station is rated by it's reception in the horizontal plane, and not vertical or any vertical component of an elliptical/circular radiation, you will receive it's rated ERP on your vector from the tower.

If any of my math or terms are elusive, ask, I will include a short Geometry and Trig lesson. It's really easy to understand.
 

EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#72
But the result is a much lower noise floor. So you appear to gain more than 2 db over a quaterwave and more than 1.15 over a halfwave.
Makes sense to me.

Effectively you raise the gain on an antenna....errr....lower the noise floor. Similar to how you can increase the range of an antenna via an amplifier.

:bunny:
 

EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#74
"New" FM antennas discovered...

AudioPrism

7500 Antenna



High performance FM antenna, omni-directional, passive design with high gain. Shiped with 15' of 75 ohm coaxial cable. Antenna element is black with a painted 13" wood base.
8500 Antenna



High performance indoor FM antenna includes hard wired 20' long remote control and 20' of 75 ohm coaxial cable. The 8500 is passive, phased array design with 4 possible antenna directions and 3 different gain settings selected via remote control; omni, 0, 120, or 240 degrees. Gain settings 0 Db, -12 and -18 Db. A 12 VDC output wall adapter included. 5 feet tall x 12 in. diameter. Black with matching painted wood end pieces.
 
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EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#75
Fantastic article on FM transmission and tuners starting on page 38 to page 49 of Issue #23 of the Audio Critic Magazine....

FM Tuners: The Present State of the Art of FM Reception

by David A. Rich Ph.D.
and then another great article following on page 50 of same issue...showing how this fellow evaluates FM tuners. Then some tuner reviews/tests follow.

How I Evaluate FM Tuners

by Richard T. Moddaferi
then on page 57 of same issue, evaluation and reviews of several indoor FM antennas...including the Magnum Dynalab Silver Ribbon, the AudioPrism 6500, 7500, and 8500 and the Day Sequerra FM Urban Antenna.

Indoor Antennas and Boosters for FM

by David A. Rich, Ph.D.
Finishing up with the Magnum Dynalab 205 Signal Sleuth on page 60 of same issue...
 

EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#77
Fantastic primer, discussion and tip here....with quite a bibliography as well. Quoted in full for posterity...

FM Reception Tips from WFLN/Philadelphia


The Problem...

Every radio and TV station has areas of less-than-wonderful reception. Most of these areas are not a result of a technical deficiency at the station rather, local topography, including hills, buildings, trees, etc., is usually the culprit. A special case for classical stations is that they tend to adjust their audio for a more "natural" sound, as opposed to more "aggressive" s tations which adjust their sound to be as loud as possible at all times. The natural sound of classical music tends to reveal every little reception flaw, while the audio of loud stations masks many ills.

Optimizing reception therefore becomes paramount when listening to classical music. These tips are designed to help you identify the cause of reception problems, choose solutions, and, finally, enjoy great music!


Identifying the Noise

Multipath: Static, noisy, distorted stereo sound, especially when music is playing, that greatly improves when switched to mono. Multipath is the most common source of problems, and is caused by signal reflections from buildings, mountains, trees, etc., just like the "ghosts" in TV reception (before cable). Multipath can occur even in strong signal areas.

Weak Signal: A relatively clear but "hissy" stereo sound, perhaps with some slow fading. The hiss is nearly eliminated when switched to mono.

Strong local station: Pieces of another station's sound splattering over the desired station.

Local interference: Interference from other sources such as two-way radios, Citizens' Band operators, and static buzz from appliances and power poles.

or any combination!


Assessing Your Chances of Success

Predicting local FM reception quality is far from an exact science. Before spending money on elaborate equipment and antennas, a certain amount of experimentation would be prudent. It can be particularly disheartening to spend time and money on a fancy new radio, only to find no real improvement.

To help predict your chances of success, try the following: carry a good, trusted portable radio (with its telescoping antenna fully extended) from room to room, listening to the station of interest. If you can get at least a fuzzy, but listenable signal in any room, chances are good that a rooftop antenna (or even a good indoor antenna) may yield very good results. Or, if you can get the station on your car radio while in the driveway or garage, this is also a good omen. If, on the other hand, you get nearly no reception at all no matter what you try, proceed with caution a fancy new antenna may be an expensive, but futile, experiment.

Careful tuning and listening are important in determining the type of reception problem you have:

1. Do you almost always hear the desired station, but it's distorted much of the time? Does the audio improve markedly when the receiver is switched to "mono"? This is a classic description of multipath (see definition above). Experimentation with a "positionable" indoor antenna may cure this problem. Severe multipath may be minimized by a carefully aimed outdoor antenna. Some newer receivers have features that help in reducing the effects of multipath.

2. When the desired station fades, does another (unwanted) station take its place, or is the channel empty (except for normal "static" and distant weak signals)? If another station on the same channel is coming in almost as strongly as the desired station, your receiver-antenna combination may be having trouble choosing one over the other. A directional outdoor antenna, pointed toward the desired station (and away from the other station)may help.

3. Is an unwanted station (or "pieces" of its program) interfering much of the time? A strong station on a nearby channel may be "splattering" onto the desired station. As above, a directional antenna pointed at the desired station may help. A good-quality receiver may be the answer as well check out the "narrow band" feature of better receivers described below.


Things To Try

The following suggestions are in a decreasing order of preference. And, as you might expect, the more involved solutions are generally near the top of the list. An exception is buying a new receiver in most cases, this expensive option is a last resort. [Contents]

Outdoor Directional Antenna

The almost universal solution to reception problems is a directional outdoor antenna. This antenna, called a "yagi," looks just like a plain TV antenna. There are dozens of different models available in the $25 to $200 price range. Important: this suggestion assumes that the radio you're using has connections for an external antenna (many table radios and most portables do not have such connections). Be sure to check the radio first. Some antenna sources:

snip...


In every case, use well-shielded coaxial cable (usually labeled "CATV" or "RG-6) from the antenna to your radio, using appropriate static drains and grounding ("coaxial lightning arrestors") where the antenna's cable enters the house. Properly installed connectors are very important buy the best and install them with care. Although flat twin-lead is theoretically less noisy than coaxial cable, the performance difference is negligible for most home installations. If you have a quantity of twin-lead on hand, give it a try, but the potential benefits of coaxial cable's shielding and ease of installation make it the cable of choice.

You can often get better results by using an inexpensive outdoor antenna with an inexpensive radio than you can by using a fancy indoor antenna with an expensive radio. A well-installed and well-maintained outdoor directional antenna alone can have a dramatic and unmistakably positive effect on FM reception, even with inexpensive or older receivers.

Directional Antenna Considerations:

If an outdoor antenna doesn't work to your satisfaction, it's very difficult to disassemble and repack for return and refund. Some stores may not allow such an antenna to be returned, except for manufacturing defects. In any event, your time and money spent on installation is not recoverable.

If you only listen to one station, or to several stations from the same direction, you can leave the antenna aimed in that direction for best reception. However, if you listen to stations from different directions, you may want to consider an antenna rotor (rotator) to re-orient the roof antenna's position. Before buying a rotor, however, it may be wise to manually optimize the antenna's position for your favorite station, then listen to the other stations. They may come in fine with that particular orientation. If not, good rotors are available from Jerrold, Winegard, and Radio Shack.

For more information on complex antenna installations, read Michael Salvati's excellent series of articles on FM antennas in the January, February, March, and April '78 and the January '79 issue of AUDIO magazine (available in any large library). Also good are Len Feldman's antenna comparison in the January '83 issue of AUDIO and Julian Hirsch's article in the May '85 issue of STEREO REVIEW.

Outdoor Non-Directional Antenna
Non-directional (omnidirectional) outdoor antennas, such as "turnstiles" and "S-shaped" may be helpful in many instances, and usually give better results than any type of indoor antenna. But if eliminating multipath and/or interfering stations is the goal, a non-directional antenna may not help. Only directional antennas can attenuate contaminating signals from other directions, such as reflections from nearby hills or buildings, or an adjacent- or same-channel interfering station.

Indoor Antenna

Indoor antennas generally do not work as well as roof antennas. In most cases, a very inexpensive roof antenna will outperform even the best indoor antenna. Again, experimentation is paramount. After connecting the indoor antenna to your radio, try moving the antenna anywhere its leadwire will allow for best reception. In tough indoor reception areas, it's important to move the antenna and, if necessary, the receiver, around the room or house, searching for a good signal spot. Try anything from a $10 set of plain "rabbit ears" from Radio Shack, to what many critics say is the best indoor model, the $200 Audio Prism APPA-8500, made by:

snip...

A visit to a high-end audio store will generally yield at least one or two fancy indoor FM antennas (along with a lot of strong opinions on just about everything to do with FM).

Often, it's very difficult to pick up desired stations inside an office building. The villains here are usually the metal-frame building (which can shield the signals and prevent them from reaching your indoor antenna), fluorescent lighting fixtures (which often produce broad- spectrum electronic noise), and interference-producing devices like computers and other office equipment. In some cases, locating a set of rabbit ears against an outside window can improve office reception. As above, it's important to try the antenna and radio in several locations around the office, sniffing out good signal areas.

Important: One positive thing about indoor antennas is that they're easy to pack up and return to the store if they don't perform. Be sure to determine the store's return policy before you purchase any indoor antenna.[Contents]

A Better Receiver[aka Tuner]

Buying a better radio, receiver, or tuner may be the most expensive route to reception nirvana, and should be considered only if your antenna efforts yielded unsatisfactory results. And there's still no guarantee that a new radio will solve certain reception problems, so determine your return/refund rights before you purchase. Talk to the equipment salesperson about your reception problem to establish why you're considering a new receiver.

A current-model receiver may only marginally improve reception, but may have other features, such as station pre-sets and digital tuning, which will aid in finding your favorite stations. Many "reception" problems turn out to be mechanical tuning difficulties with a hard-to-read or poorly calibrated dial, a problem quickly solved by a radio with digital tuning.

Important radio technical specifications to look for are:

Alternate-Channel & amp Adjacent Channel Selectivity: this refers to the ability to separate stations close to each other in frequency. Higher numbers indicate better performance.

Usable Sensitivity: the minimum signal strength needed to provide a quiet, undistorted audio (the lower the number of microvolts or femtowatts the better).

Capture Ratio: the radio's ability to select one station over another, based on the difference in their strength the lower the number, the better.

AM Rejection: doesn't refer to AM stations rather, this specifies how successfully theradio ignores noise-producing level variations (static, sputtering, etc.) in the incoming signal. The higher this number, the better.

Image Rejection: refers to the radio's ability to suppress internally generated spurious noises and squeals, especially in the presence of strong signals or signals of c ertain frequencies the higher the better.

Most modern radios have respectable stereo separation and frequency response, as well as low residual noise and distortion. The real tests are the specifications listed above these will make the most difference in difficult reception situations. Many better receivers have other features that may help in poor signal situations see Compromises below.

Antenna Amplifier

If the basic signal is weak, but otherwise free of multipath distortion and interference, you can sometimes benefit by the use of an RF (Radio Frequency) amplifier in the antenna line. If you live anywhere near a radio or TV station, however, there's a strong possibility that the station may overload the antenna amplifier, causing more problems.

As always, start by trying an inexpensive amplifier, and bring it back if it doesn't help. Considered one of the best is the model 205 "Signal Sleuth" Tunable FM Signal Amplifier from MagnumDynalab at:

snip...



Compromises

Of course, our goal is crystal-clear stereo reception, but if you can't receive the station cleanly in stereo, switch the tuner or receiver to its mono mode. Often, just switching to mono will substantially reduce noise, static, and multipath distortion.

The best radios provide "narrow I.F. bandwidth" modes, which can effectively notch out nearby interfering stations on the dial. While these modes tend to increase distortion slightly, they can often make a noisy distant station completely listenable.

"High-Blend" is another common feature. This circuit helps multipath and weak signal situations by decreasing the high audio frequencies (where most of the noise is) and by reducing stereo separation.

Sometimes one or several of the above special modes in combination with each other can make a dramatic reception improvement.
 
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EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#78
continued...

Interference Filters

If you're experiencing local interference problems (static, hiss, crackling, pops, noise, etc.), and are fairly sure it's not multipath, try to find the interference source. Possibilities: arcing high-tension power lines, poorly grounded motors, appliances, spark plugs from passing cars, etc.

In these instances, there is no substitute for an experienced ear. If you know someone with electronics expertise, perhaps a local amateur radio operator, try to arrange a visit. S/he may suggest a number of possible cures, including filters for the interfering devices, as well as on the FM radio's power line, antenna line, and audio cables. Experimentation with grounding some or all of your components may also help.

A large variety of power line filters, and RF (Radio Frequency) filters (for the antenna line and/or audio cables) are available from:

Electronic Specialists
171 S. Main Street
Natick, MA 01760
(800) 225-4876

If you confirm that a powerful local FM station is preventing your reception of a weak, distant FM station on a nearby frequency, you can use the "narrow IF" modes on good FM radios (described above) to improve selectivity. A last-ditch attempt would be to try a special "notch filter" at the antenna connector, to attenuate the interfering station. The Blonder-Tongue MWT-2b is such a filter, and costs about $140 and is available from:

snip...

If all else fails, and you have reason to believe that the interference is malicious or illegal, contact the FCC:

snip...

The FCC is overworked and understaffed, and may not be able to respond immediately (if at all).

Cable TV/FM Connection

A possible solution, not available to everyone, is your local cable TV company. Although many cable TV systems dropped all FM station carriage some time ago, some systems still carry a few FM radio stations in addition to the TV channels. Check with your local cable company. If they don't offer FM, register your disappointment! Even though FM reception from the cable is often slightly degraded, it's better than none at all. [WNKU Note: Warner Cable in Cincinnati continues to offer FM, but doesn't advertise it TKR in Kentucky no longer offers an FM service, instead providing Digital Music Express (DMX), a satellite audio service.]
 
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EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#79
References: Magazine Articles...


Brinton, James: "Supertuners Are They Worth It?", High Fidelity, December 1975, pp. 59-65

Clifford, Martin: "Language of High Fidelity Part XI (Tuners)," Audio, May 1974, pp. 28-34

Feldman, Leonard: "An Empirical Study of FM Antennas," Audio, October 1969, pp. 26-32

Feldman, Leonard: "FM Specifications Revisited," Audio, April 1978, pp. 58-66

Feldman, Leonard: "New Tests and Standards for Tuners and Receivers," Audio, Jan.86, pp. 38-44

Feldman, Leonard: "11 Outdoor Antennas Analyzed," Audio, January 1983, pp. 41-47

Foster, Ed: "Interpreting FM Tuner Specs," High Fidelity, November 1977, pp. 72-75

Giovanelli, Joseph: "Remedying RF Interference," Audio, January 1977, pp. 29-32

Hirsch, Julian: "Audio/Video Antennas," Stereo Review, May 1985, pp. 44-48

Hirsch, Julian: "FM Tuner Specifications," Stereo Review, November 1990, pp. 43-44

Hirsch, Julian: "FM Tuning," Stereo Review, February 1980, pp. 35-36

Hirsch, Julian: "FM Tuners in Town and Country," Stereo Review, February 1984, pp. 44-50

Hirsch, Julian: "FM Tuner Sensitivity," Stereo Review, Sept. 1981, pp. 35-36

Klein, Larry: "FM Multipath," Stereo Review, November 1986, pp. 98-99

Long, Robert: "How to Read Our Tuner Curves," High Fidelity, August 1988, pp. 46-48

Masters, Ian: "How to Get Better FM Reception," Stereo Review, April 1991, pp. 70-72

Mitchell, Peter W.: "How to Buy a Tuner," Stereo Review, November 1987, pp. 93-97

Modafferi, Richard: "Kill FM Interference with Two Antennas," Audio, January 1980, pp. 68-72

Riggs, Michael: "Basically Speaking: Radio the Inside Story," High Fidelity April 1986, p. 21

Riggs, Michael: "Front Lines: Progress in FM Tuners?", High Fidelity May 1989, p. 5

Riggs, Michael: "How to Buy a Tuner," High Fidelity, December 1980, pp. 50

Rosenberg, Fred: "FM Antennas Parts 1 and 2," Sounds LIke issues #5 and #7

Salvati, Michael J.: "FM Antennas" [five-part series partially based on book above], Audio, January, February, March, April 1978, and January 1979

Sell, Gordon: "Tuner Design Forum," Stereo Review, April 1982, pp. 49-53

Von Recklinghausen, Daniel R.: "How to Evaluate FM Stereo Tuner Performance," Audio [month unknown] 1973 reprinted in 1974 Annual Issue

Warriner, William: "RX for RF Interference," High Fidelity, March 1976, pp. 56-59
 

EscapeVelocity

Moderator, , Webmaster of EV's Antenna Blog
#80
Good tips from bazz on cable, wires, connections....etc....

bazz's guide to FM antenna connection

Apropos of nothing really, but installing my new FM antenna put me in mind of all the small things which can prevent the signal which arrives at your tuner from being a mirror, if slightly attenuated, image of that generated by your antenna.

I’m not a professional in this field, but I do have a fair bit of experience and have learnt from my mistakes over the years.

I'll assume that you have a purpose-built roof or loft mounted FM antenna pointed at the transmitter, and that you don’t use 300 ohm ribbon to connect it to the tuner. (Ribbon actually suffers from much less signal attenuation than coax, but is horribly prone to RFI and multipath distortion)

If you are able to install an external Yagi then mad if you don’t. An indoor antenna or external half wave dipole will deliver but a fraction of your tuners potential.

Start with the balun, the little gizmo usually found at the antenna end of the cable which converts the balanced 300 ohm output of the antenna to the unbalanced 75 ohms impedance of coaxial cable and (probably) your tuner input. Most antennas come with a PCB balun already attached but some (such as mine) don’t. If you have to buy one, spend a couple of extra dollars/quid to get the best one in the shop as, believe it or not, an inefficient balun will absorb around 80% of the signal fed into it.

When you attach the balun to the antenna, make sure the flexible wires are kept equidistant between the attachment points on the antenna’s driven element and the balun body to maintain 300ohms impedance.

Coaxial cable: Turf that old RG59 coax in the shed. Use quality double screened RG59, RG6 or, preferably, quad screened RG6 as used in satellite TV installations. The quad screened stuff is a bit thicker and a bit awkward to work with, but worth the effort (heard that before somewhere?)

Coax relies on the screen to keep interference out and signal in. I have seen cheap RG59 with 20% braid coverage, which is hopelessly inadequate. The best coax has alternate layers of copper foil and braid screen with an air spaced dielectric (insulator) and a copper coated steel conductor.

Make sure too that the braid and foil are made of the same material. If they're not, electrolytic corrosion will occur when the cable becomes damp. Have a look at coax which uses differing screen materials after six months use and you’ll see that the conductor is black from corrosion. Alternatively, attach a zinc anode (just kidding!)

Also, when you’re terminating the coax with a balun or plug, make sure that no part of the screen comes into contact with the conductor, not even one stray strand of braid. (This may seem obvious, but I’ve seen some strange things when helping friends with their installations.)

Cable attenuation: Not really an issue at FM frequencies and with relatively short (say less than 50m) cable runs. Still worth keeping in mind though that the difference in attenuation between the best and worst cable is around 6db over 100 metres at 100 Mhz and we’re dealing with signals measured in microvolts.

Cable Routing: Don’t run the coax alongside AC mains cable. Even the best coax is only 85% effective at rejecting RFI/multipath/induced interference. If you have to cross a mains cable, do it at right angles and try to maintain some clearance.

Cable Joins: Avoid them. A join will result in reflections/standing waves, which will certainly compromise the VSWR the engineer who designed your antenna spent sleepless nights achieving. The same applies to wall plates, though I realise they are often a domestic necessity.

RF (booster) amplifiers: Avoid them at all costs. They will introduce noise and distortion to the signal and they kill music stone dead on contact. If you have a weak signal get a more efficient antenna.

Plugs: I personally prefer F connectors, but if your tuner uses a Belling Lee (PAL) type, then use one you can solder.

If all this sounds inconsequential I assure you it's not. The difference between cheap RG59 and quad screened RG6 for example is clearly audible in my system, and I only have 14 metres of cable between antenna and tuner.
 

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