Antennas for FM Radio Reception

Bob Klacza tests and reports on the performance of simple FM radio antennas. Robert Klacza is the holder of FCC General Radiotelephone Operator License Number PG-19-12913, issued on January 2, 1985, valid for the lifetime of the holder. He has worked at four different AM and FM broadcast stations since 1967. He also was the Design and Release Engineer for AM, FM, and Sirius/XM Antennas in vehicles for over 10 years, with extensive experience in polar pattern measurements.

[JamesSmith-flky]

Thanks for this video, helped me select a home FM antenna which is a largely ignored product in today's digital streaming world.

[victoryfirst]

This is the best video I have seen on the subject at hand. Well done.

[themoviemaniac]

Those goofy T-wires provided with the purchase of a receiver work fine for most people in or near urban areas looking to get only a couple of favorite channels, which is most people in the country now. We who live in rural areas appreciate your information to help us getting those distant broadcasts.

[GateKommand]

I am a licenced Radio Amateur and should be aware of the majority of this information. However I found it very interesting and enlightening, thank you for the presentation mate!

[mechantgarcon]

Very glad to know such a group exists. Thanks for sharing informative content! Wish you all good health and long life!

[ARJUN-SS]

Thank You for sharing this information i love Radio. Good to see Radio lover's talking about FM antenna.

[hernanrodriguezsilvera]

Brilliant conference... greetings from Montevideo, Uruguay...!!!

[Gena]

Thank you for your advice about a whip antenna, and about what its optimal length should be. I have a Sony receiver with a 75 ohm coaxial connection. I found a 30-inch (75 cm) whip antenna with a 30 inch cord, and it works perfectly ... no amplifier needed! I propped it up in a window with a venetian blind, and I now get great reception of an FM station I like, that is 60 miles away! A cheap and very effective solution ... thank you!

[pizzaface]

I learned more about FM in this video than trying to research it on my own in years. Thank you Bob for your knowledge I am going to have to try your methods. The higher the antenna the better the signal, so true. DXing is awesome.

[m.ericwatson]

I just thought about building a radio antenna at my property in Park county, Co., was sitting at Chatfield reservoir listening to am radio, thought "this is quaint, I like AM radio" then the lightbulb went off, I could erect an antenna and get really good radio signal up there, long story long, found Bob here explaining proper signal capture and antenna positioning and he's is an engineer so he knows his stuff, thanks Bob!

[patrickbullock]

I mounted four of these folded dipoles vertically and used RG62, 93 ohm cable with a balun at each antenna. I used a spectrum analyzer to phase each antenna and use the correct length of RG62 to raise the impedance of each antenna to 3oo ohms unbalanced. When the antennas were connected together, the unbalance impedance became 75 ohms. Since the FM broadcast band is rather narrow, I could easily phase the antennas Outstanding reception!

[tommyb.]

I'm 32 and i would had loved to be in that room. Thanks for the demo.

[IgnacioSanchezWebDesign]

Thanks for sharing such an interesting video. I am from Cuba and I always was a FM band lover. I had several antennas to "catch" radio stations from Florida and one of my favorites was a
7-element yagi, along with a
3-step booster which I put right on the mast about 1 foot from the dipole. It was sealed and protected from rain. Oh man! That setup worked like a charm!!!
Power supply was down by the tuner and I used the same 75 ohm coaxial cable to power up the Booster. Amazing guys! I wonder how many stations I'd get here with such a system!!! Okay, thanks again and till your next video.

[chaseprice]

thank god for youtube i was looking for stuff like this explained easy

[roberte.andrews]

I'm fortunate to live in a signal-rich urban area and pull strong signals with just an old 300-ohm floppy dipole strip, which I reposition, depending upon atmospheric conditions. That, and a receiver with a good FM stage, has served me well these past 60 years. Our village is the western-most portion of San Diego suburbs and it's a straight shot up the coast to the high antennas sited in the mountains east of the Los Angeles Basin. As I am 400 feet from the Pacific, there is virtually no multi-path phenomenon, because I am sticking out from the continent enough to allow line-of-sight between my cheapo dipole ribbon and the transmitters high atop the coast range of mountains to the north. So I get good signal strength and quite a bit of separation, even though it's almost 100 miles between us! My Fisher receiver, circa 1978, was made with Avery Fisher's patents in Japan and has one of the best FM stages I've encountered, but my two Marantz receivers were equally as good, too. This gear benefitted from American know-how and Japanese expertise in manufacture. I believe that accounts for the popularity of the big super-receivers of the 1970s today. They offer enough stable power to drive even an inefficient speaker system and great FM reception, too. I found no superiority in my high-end Tandberg separate components with their miles of interconnecting cables which may or may not have been picking up RF signals, given the traffic density here. I know it sound like heresy, but I think receivers with their short coupling paths between sections result in a cleaner signal than individual amp-preamp-tuner arrays and all the potential corrosion effects at contact points in this marine (saline) environment. At least it provides less chance of tripping over yards of cables and neatens up your listening area. Wives and sweethearts like the sound, but often balk at the hardware scattered about. I first dropped a needle on a record in 1940, so I've been around the platter several million times! Thanks, Robert, for a thoroughly professional and useful presentation. My brother Jimmy was Chief Plant Engineer for Pacific Bell here and had 12 patents of his assigned to AT&T over the years, so I have some experience with your area of expertise.

[jamesking]

Bob: Thank you for this video. Couple questions: 1) Where can I purchase a folded dipole antenna for FM radio reception? 2) I plan to mount it on my TV antenna mast. My TV antenna is a "Televes 148883 Antenna Ellipse Mix ". 2) Where on the mast, relative to the TV antenna, should I mount the FM dipole. Many thanks. Jim King, Saratoga County, NY

[maxenielsen]

Nice video! Thanks very much! Didn't know that circular polarization was pretty much standard.

Stove-Pipe Dipole
Armed with that information about circular polarization, I built a dipole out of two pieces of 8" (trade size) / 7" (actual size) galvanized HVAC duct. Each arm of the dipole is 690mm or a bit over 27" each. I put a 1" space between the ends where the 75 Ohm CATV cable connects. I did not use a balun of any sort, as the two pieces of stove-pipe make a very good match to 75 Ohms at the middle of the FM band, and I was not too concerned about disruption of the pattern because of feed line currents. Because of the large 7" diameter of the stovepipe, the antenna is fairly broad band.

The antenna seems to work well. I have made some measurements like those you give in your video, so far just for the stovepipe dipole (which I hung vertically in my attic and connected via 75 Ohm CATV cable to my radio in the basement). Have not yet made measurements on other antennas on hand.

Noise in FM Broadcast Reception
This was all in an effort to clean up some "steam" or "scratchiness" that seems to be always present in music received through this radio. I am a bit perplexed how to get rid of it. Even though my radio shows a good strong signal (as I assessed by measuring the voltage at the S-meter output of the FM IF chip), I still hear some scratch in the music. Do I not have a strong enough signal? Perhaps the scratchiness is because of the demodulation method used in the radio? The radio, by the way, is a Kenwood KR-A46 AM-FM stereo receiver., about 1987 vintage. It is frequency synthesizer-controlled, and I have not attempted to align it, though I do have the factory service manual that describes the alignment procedure. I just picked it up at a thrift store recently, so I don't have a great deal of experience with it. Maybe a fully analog FM receiver would have less "scratch"?


Thanks again for the very informative video. Good engineering!

Max

[billman]

Thanks, just what i was looking for to get my new HD kenwood radio to stay locked in, Im gonna check on the round one.

[hubkap]

Where could you purchase an Antenna like the one shown at the 2:15 mark in this video? Is there any videos on Youtube that shows how to make one?

[ntoslinux]

Excellent video. Props to the video editor.