Dipole FM antenna Vs. Amplifed FM antenna (eventually HD Radio on my Onkyo TX-NR808)

mhardy6647 wrote: »

Do you live somewhere that permits you to erect an outdoor antenna and/or can you put one in the attic?
Altitude will gain (pun intended) you more than anything else! :-) The standard dipole is not a bad antenna, believe it or not. The problem with amplified antennae (indoors or out) is that they don't improve the signal to noise ratio of the reception (i.e., they amplify both the signal and the noise).

A directional FM antenna, rotator, and altitude will get you the best signal possible. If all stations are in one direction from you, you won't even need the rotator.

EDIT: Here's a good example that Winegard "Chromstar" would be a good choice for you. No affiliation with the vendor (except as a satisfied customer; they're fairly local to me).
http://www.starkelectronic.com/fm.htm

EDIT^2: The "J-pole" design is also highly regarded; I have no experience myself, but here's a thread from audiokarma on the J-pole.
http://audiokarma.org/forums/showthread.php?t=143368

X2 on the directional!! If you have an old school tuner with a multipath meter you can really dial it in.

well there are some better amplified antennae. One that remains popular is an amplified whip sold by high-end tuner maker (the last one extant, more or less) Magnum Dynalab: http://www.magnumdynalab.com/fmantenna-st2.htm These ain't cheap, but some folks like them quite a bit. They can IIRC be used inside or outside (maybe you can stick it out a window...?) :-)

Another commercial FM indoor antenna which has polarized (no pun intended) folks considerably is the "Godar" antenna. It's small, seemingly simple, but not particularly cheap. It is not amplified but said by some to work quite well. I've never seen one so I have no opinion. http://www.godarusa.com/id67.html


That said...

Try a dipole; best thing about 'em is that you may tune them to length if one is mostly interested in a specific frequency or region - e.g., the "public service/college" radio band below 92 MHz). You can buy a cheap one anywhere or an expensive one from CC Crane or make your own with 300 ohm twinlead. You can still buy that, too (or send me a PM and I'll mail you some!). Here's a recipe for a DIY dipole. http://www.cyberpoet.net/writes/web/infwiz/spant.html

A 300 ohm dipole is the reference FM receiving antenna and has (essentially by definition) zero gain. It also has a figure 8 shaped receiving pattern; it will be sensitive to radio signals coming at it perpendicular to its arms while essentially ignoring any signal beaming towards its "tips". If you put it up high and can align it properly, it is NOT a bad antenna design at all.

EDIT: For completeness, here's the CC Crane "Reflect" dipole: http://www.ccrane.com/antennas/fm-antennas/fm-reflect-antenna.aspx
I'd think hard before shelling out that much for an FM dipole (about 20x the cost of a generic one).

Another interesting antenna is this one, which I believe is technically a cubical quad:
www.wryr.org/Antenna_instructions.pdf
Cannot vouch for it, but it'd be fun to try.

you won't need a balun with the R/S antenna unless your tuner/receiver only has a 75 ohm antenna input... oh, I guess the HD (hybrid digital) tuners likely do have only 75 ohm input, eh? :-P

PS The unfortunately discontinued Sony XDR-F1HD is probably the best way to go when/if you go HD - supposed to be a very good performer even stock; analog or digital. See http://www.radioxtuners.com/ for info.

you are correct, sir. Don't mind me, I am an old guy and I come from the days that tuners and receivers had 300 ohm screw connectors for twinlead :-P



Sorry, you mentioned the Onkyo module in your first post and I just spaced on it.

I have a tuner with 300 ohm balanced inputs and a 75 ohm unbalanced input from the antenna....the info. out there seems mixed and 300 ohm wire is outdated vs. coax. Any thoughts which would produce a better signal?:question:

inspiredsports wrote: »

Coax is 75 ohm impedance and the screw terminals are 300 ohm for old flat antenna wire that delivered a 300 ohm signal.

You need a "balun" adapter (short for balanced/unbalanced) which has the 300 ohm two wires on one side and a 75 ohm male coax thread on the other.

You do get a bit of signal loss through a balun. I can't remember the brand, but there is one brand that has very little loss and maybe someone who knows will chime in. I have one, but the printing is worn off and I can't remember the brand; it might have been as simple as Radio Shack.

So, if one had a choice between 300 ohm and 75 ohm wires, which would deliver a better signal from the antenna?
I have already run coax from my attic to the basement, but now am wondering if I should run 300 ohm wire instead...

The performance of the simple "T" dipole is pretty astonishing, really. Folks assume because they're just two pieces of wire and they cost, like, a buck-fiddy that they must be profoundly inferior. They're actually the reference (0dB) point for FM antennae. They're not the sine qua non but they do have their advantages (e.g., tucking them up above a window frame, out of sight behind the window treatments, if that matches the reception pattern you need).

The whole subject of antennae is amazingly complex and somewhat arcane. I have an ARRL antenna book that is the size of an old-fashioned metropolitan area phonebook :-)

Glad to hear it improved your lot.

I think 75 ohm coax either has less loss of signal or picks up less RF interference over the length of a typical run, so that is why it has pretty much replaced 300 ohm twin-lead wire. There's probably not much call for audiophile grade twin-lead

jbooker82 wrote: »

Well I just though I would update you guys. I just swapped out the single wire FM antenna that came with my Onkyo for a Radio Shack Dipole antenna, and a GE (purchased from walmart) Balun. The FM reception is a night and day difference. All the stations I could get with the regular FM antenna are now really clear. I can get some FM channels pretty clear from Omaha, and some are staticy. Ethire way it was a nice upgrade for 10 bucks.

Atta boy! I would have bought a directional Yagi. But, the foldered dipole does work pretty good. Mount a Yagi on your roof and be amazed. FM sound much better when you can get your antenna in the open air and "point" it to the direction of the signal transmission.

Check out FMfool.com for some hints to locate transmission towers in your area. Happy listening!