Um, not quite, Brett. How about 300 million divided by Frequency in hz? That gets you the length of a full-wave i.e. 300 million divided by 7500000 gives you 40 meters; which is 7.5Mhz.
If you divide 300 by the frequency in Megahertz, you'
ll get the same result. That is, you'll get the wavelength in meters. For the FM band, with a center frequency of 98Mhz, you'd have 3.061224 Meters, which is 10 feet .5 inches.
Steve, K8SP
----- Original Message -----
From: Brett Winches
To: [log in to unmask]
Sent: Monday, May 14, 2007 10:15 AM
Subject: Re: off topic fm and am antanna help
The basic antenna formula will get you close 300000000/frequencey MHZ
and than do the metric to English conversion if needed. Otherwise, do
the 468 over frequency. =20
-----
BRETT WINCHESTER
[log in to unmask]
208-639-8386
###
-----Original Message-----
From: For blind ham radio operators
[mailto:[log in to unmask]] On Behalf Of Pat Byrne
Sent: Sunday, May 13, 2007 11:18 AM
To: [log in to unmask]
Subject: Re: off topic fm and am antanna help
An antenna cut to frequency is just that, I would venture. So, HDTV is
more than likely a marketing strategy.
Simple is good; I would use a folded dipole, about forty inches on a
side, made of 300 ohm feed line, and fed with the same feedline. Simple
and inexpensive.
Good luck.
Pat, K9JAUAt 10:37 AM 5/13/2007, you wrote:
>some one also recommended a hd tv antanna would this work as well?
>thanks
>Hank
>----- Original Message -----
>From: "Ken" <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Sunday, May 13, 2007 5:01 AM
>Subject: Re: off topic fm and am antanna help
>
>
> > Hi Hank, I've done much reading on this subject of improving fm=20
> > reception with an indoor antenna. As you already learned, amplified
> > antennas don't work. I also tried the BesBuy indoor active Terk fm
tower with no luck.
> > I
> > really don't think you can do much better than the good old rabbit=20
> > ears antenna for indoor antennas. The trick to using one of these=20
> > antennas is getting the right location and orientation. On some=20
> > stations just moving the elements an inch or so will cause me to=20
> > lose my station. Also try setting the elements to about a 40 degree
> > angle and then tip the setup in the direction that gives the best=20
> > signal. If you can get the rabbit ears into a crawl space in to
the attic this might help.
> >
> > Try a loop. Length is 1005/Freq in Mhz (about 10 feet for fm). =20
> > Connect the ends of the wire to the 300-ohm side of a 300 to 75 ohm=20
> > balun.
> >
> > Below I've listed a couple of antennas I'm researching, but have not
> > tried.
> > They are both really just dipoles but these antennas are often=20
> > mentioned in the audiophile articles I like to read.
> >
> > The Silver Ribbon Antenna by Magnum Dynalab The SR-100 (I think it's
> > about $35 if you can find one) A high-efficiency indoor antenna that
> > is ...
> > . Continuously tunable across the FM dial to maximize reception, .=20
> > Rotatable for best station orientation.
> > . Designed to complement just about any FM system arrangement.
> > . Receives local HDTV signal with ease due to its UHF design.
> > . Directionality helps in solving problems due to multi path=20
> > interference
> >
> >
> > And then Ccrane has a $35 dipole (I think it's just an off-center=20
> > fed dipole), but it might be worth a try. About $35.
> >
> >
> > Good luck,
> > 73, Ken -N5SWR
> >
> > -----Original Message-----
> > From: For blind ham radio operators=20
> > [mailto:[log in to unmask]]
> > On Behalf Of hank smith
> > Sent: Saturday, May 12, 2007 6:49 PM
> > To: [log in to unmask]
> > Subject: off topic fm and am antanna help
> >
> >
> > Hello.
> > I am trying to pull in some week signals out of seattle wa from=20
> > olympia wa.
> > I am running a boston acoustics recepter currently I am using a pair
> > of rabbit ear tv antanna's in the horzontal possission and am=20
> > getting a little better results but I am needing a bit more=20
> > recieving power on fm and I am also needing some am recommendations.
> > I purchased a amplified am/fm antanna from terk for 30 dollars from=20
> > best buy
> >
> > and it was the worst performming antanna that was amplified I ran in
> > to even
> >
> > with the amp maxxed, it had a amp dial that you could adjust.
> > any recommendations for indoor use that I can purchase at a local
store?
> > either from radio shack best buy or some other place?
> > thanks
> > Hank
> >
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > Version: 7.5.467 / Virus Database: 269.6.8/800 - Release Date:=20
> > 5/11/2007
> > 7:34 PM
> >
> >
> > No virus found in this outgoing message.
> > Checked by AVG Free Edition.
> > Version: 7.5.467 / Virus Database: 269.6.8/800 - Release Date:=20
> > 5/11/2007
> > 7:34 PM
> >
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