antenna?

[hermanv]

If the signal is just plain weak, then a directional antenna and a way to aim it is the solution. Most TV antennas pick up FM just fine and can be found dirt cheap at garage sales etc. The more elements the higher the gain and the more directional they become.

If you are lucky then all the stations you want to hear are in the same direction and you can permanently aim the anttenna that way (in the attic sometimes works, on the roof is best).

Now multipath is a different critter, often sounds are garbeled or grainy, sometimes the volume goes up and down fast, kind of like a motor boat. Multipath is a problem in cities with high rise buildings or in hilly areas.

The best solution for multipath seems to be a very directional antenna, one with many elements probably with a boom that's 6 to 10 feet long. By aiming this monster carefully, a clean signal can often be found but it may or may not be pointed directly towards the station. Worse it may need to be aimed differntly for different stations.

If you have cable TV, many cable companies add FM stations to the cable signal. You will need a splitter and a band seperation filter often also called a splitter (good Ol Radio Shack, try and get one that has VHF/UHF/FM outputs) The first splitter (usually a little silver metal can) goes between your TV and the cable outlet on the wall. The second goes between the first splitter and the new cable to your receiver FM input. (It might work without the second splitter) Most frequency splitters have 300 Ohm outputs, often a little short piece of twin lead, so you will also need the 300 to 75 Ohm adapter mentioned earlier in the posts.

[Whatever6750]

its not to weak i think its more a problem of not rilly haveing any ware to place the antenna and interference from other stuff.. Like if the antenna is with in 2-3 feet of my computer theres barly any signal. Think ima just try and find a way to rig up something out side...

Is there any such thing thats like whats used for like cb radios for cars/trucks where the antenna is on the out side and another thing on the inside. I.E something that wouldent requier runing a wire out side..

Sorry about the spelling..

[Whatever6750]

if you have cable TV, many cable companies add FM stations to the cable signal. You will need a splitter and a band seperation filter often also called a splitter (good Ol Radio Shack, try and get one that has VHF/UHF/FM outputs) The first splitter (usually a little silver metal can) goes between your TV and the cable outlet on the wall. The second goes between the first splitter and the new cable to your receiver FM input. (It might work without the second splitter) Most frequency splitters have 300 Ohm outputs, often a little short piece of twin lead, so you will also need the 300 to 75 Ohm adapter mentioned earlier in the posts.

I did not know that. To bad theres no cable jacks in the room :-(

[nightflier]

Herm,

So I can use the same antenna for FM as I do with TV with a splitter?

Also, if I have several radios in the house, how many times can I "split" the signal?

While we're on the subject, can I combine antennas on a single cable? Will that improve things if one is omnidirectional and the other directional?

[hermanv]

Nightflier:
Each splitter will cost you 1/2 the signal strength or 3dB (no free lunch) but a band splitter if properly made will not cost 1/2 the signal (i.e all the FM will go to one output all the TV to another). They make 3, 4 and even 6 output splitters if you have a strong signal or cable that works fine. They even make amplified splitters, 'course those use a wall wart.

Yes you can "add" antenna signals but the weaker one will deplete the stronger in this case. Unless each antenna is a single frequency model. In worst case scenarios, I've seen installations with several single channel antennas facing different directions sumed with a splitter.

Whatever6750:
I have never seen a through wall/window coupler for FM you can make one but it will look silly. Paste one of those "T" shapped antennas on the outside of a window run the wires to the antenna on the roof. Paste another "T" shaped antenna on the inside of the window as close and aligned with the outside one as possible. The two antennas will couple the signal right through the glass.


Suppose a hill or cliff blocks the signal from the city? I have seeen people place a high gain antenna on the hill behind their house, with that antenna wired directly to a second antenna facing down the hill towards their house. Now a third antenna on the rooftop aimed at the second antenna on the hill will let the house "see" over the hill. Neat eh? (Lossy, yes, but workable)

[Whatever6750]

Whatever6750:
I have never seen a through wall/window coupler for FM you can make one but it will look silly. Paste one of those "T" shapped antennas on the outside of a window run the wires to the antenna on the roof. Paste another "T" shaped antenna on the inside of the window as close and aligned with the outside one as possible. The two antennas will couple the signal right through the glass.


Suppose a hill or cliff blocks the signal from the city? I have seeen people place a high gain antenna on the hill behind their house, with that antenna wired directly to a second antenna facing down the hill towards their house. Now a third antenna on the rooftop aimed at the second antenna on the hill will let the house "see" over the hill. Neat eh? (Lossy, yes, but workable)

Humm. So antenna on the inside of the windo and another on the outside lined up exsactly with it?

Also i dident menchon this before but i do have a old antenna on the top of the roof. One of those big ones. It has no motor and just some kind of wire comeing from it about 4ft long. If i under stand what u said corectly i could run a wire from the antenna from it to a T shaped antenna on the out side of a windo and then one on the inside matched right up to it? That could work if the antenna on the roof works or can be fixed or something.

[Smokey]

While we're on the subject, can I combine antennas on a single cable? Will that improve things if one is omnidirectional and the other directional?

Bad idea. Although two antennas can be sumed to one cable, they have to be same type and pointed in the same direction for added gain. Combining an omnidirectional and directional antenna will introduce noise in the system (noise coming from omnidirectional antenna) and defeat directional capabilty of latter antenna.

Directional antennas will only pick up signal from direction it is pointed to, and reject noise coming from any other directions. By combining both, noise from any other directions will be injected into cable.

Suppose a hill or cliff blocks the signal from the city? I have seeen people place a high gain antenna on the hill behind their house, with that antenna wired directly to a second antenna facing down the hill towards their house. Now a third antenna on the rooftop aimed at the second antenna on the hill will let the house "see" over the hill.

Sorry, but that will not work. Antenna on the rooftop will not see any signal if signal is blocked by the hill. Antennas will only receive and not transmit (unless it is a transmitter)

Also i dident menchon this before but i do have a old antenna on the top of the roof. One of those big ones. It has no motor and just some kind of wire comeing from it about 4ft long. If i under stand what u said corectly i could run a wire from the antenna from it to a T shaped antenna on the out side of a windo and then one on the inside matched right up to it? That could work if the antenna on the roof works or can be fixed or something.

Sorry, that will not work. Best solution would be to run a strait line from antenna to your receiver to take advantage of antenna. You may have to get up on the roof to adjust the antenna for best signal and lowest noise

[Whatever6750]

Sorry, that will not work. Best solution would be to run a strait line from antenna to your receiver to take advantage of antenna. You may have to get up on the roof to adjust the antenna for best signal and lowest noise

I dont rilly have a way to run a wire into the house.. :-(

[hermanv]

Sorry, but that will not work. Antenna on the rooftop will not see any signal if signal is blocked by the hill. Antennas will only receive and not transmit (unless it is a transmitter)

Sorry, that will not work. Best solution would be to run a strait line from antenna to your receiver to take advantage of antenna. You may have to get up on the roof to adjust the antenna for best signal and lowest noise

Smokey, you not only get it wrong but you get it wrong twice. If you drive a voltage of the correct frequency into an antenna it will transmit that signal. This is just as true for millivolts as it is for kilovolts. There is just no difference between a transmitting antenna or a receiveing antenna. Using a passive antennna coupling is no different from using a transformer both will couple a signal through a gap. I have done this, it works. No it is not as good as a direct wire connection, it is lossier but not by that many dB.

How do you think those car cell phone through glass couplers work? And they work both ways, transmitting and receiving. People with radio transmitters usually use the same antenna to listen as they do to send, really all antennas work both ways, no magic.

[Whatever6750]

I just got one of thease http://www.partsexpress.com/pe/showd...number=210-020 and im useing a 300 to 75ohm adaptor and seams to pick up radio siganls a bit more but also picks up static more. My favorite station comes in good thow.

cence the antenna is so cheap i might just try the throw window thing. Eavn if it dosent work it wont rilly matter becuse the antenna is soo cheap. like $1 from PE whitch im starting to rilly like haveing localy. Thay have a a little showroom/store up in front that pritty nice.

[nightflier]

Our neighborhood has rather draconian association rules and placing antennas above the roofline is a big no-no. If I wanted to cheat and use a T-shaped antenna and run it along the slanted roofline of my house, at the gable so that it would hardly be noticeable (instead of a T-shape, it would then have more of an upward-facing arrow shape). I could get away with this if the wire is thin enough as it won't be visible from the street where the narcs will be looking for it.

Would the non-T shape affect performance?

[hermanv]

The long leg of the "T" is really not part of the antenna, it is simply the output wire. If you run it parallel and close to one of the "T" arms unforntunately it becomes part of the antenna though.

The edge of the roof will be OK if there is no gutter or at least not a metal one. It will work better if it is spaced away from the roofing material especially when it rains.

Those "T" antennas have no gain they will not do much in low signal strength areas, think of them like "rabbit" ears for TV, a desperation measure.

[Lensman]

Our neighborhood has rather draconian association rules and placing antennas above the roofline is a big no-no. If I wanted to cheat and use a T-shaped antenna and run it along the slanted roofline of my house, at the gable so that it would hardly be noticeable (instead of a T-shape, it would then have more of an upward-facing arrow shape). I could get away with this if the wire is thin enough as it won't be visible from the street where the narcs will be looking for it.

Would the non-T shape affect performance?

If you have an attic, you could actually mount an outdoor antenna inside it. Just nail up something like a broom handle, run some wire and clamp on the antenna. Though the close proximity of the house's structure, roof and any wiring up there will compromise the antenna a little, a reasonable yagi/TV antenna in an attic will still beat a T-antenna outside by a considerable amount. As mentioned above, your method of mounting the T-antenna also weakens it (anything closer than about half a wavelength becomes part of the antenna). Quite a number of people in outlying areas use attic-mounted antennas to pick up weak stations with great success.

[Smokey]

There is just no difference between a transmitting antenna or a receiveing antenna.

That is true. But one really need "power" to overcome losses by antenna (as antenna itself is not %100 efficient) and to project any type of signal. Signal strength the antenna on the hill will receive probably will be microvolts range, and that will not be enough juice to drive another antenna to transmit signal down the hill.

You said you seen poeple place a high gain antenna on the hill behind their house, with that antenna wired directly to a second antenna facing down the hill towards their house. And a third antenna on the rooftop aimed at the second antenna on the hill will let the house "see" over the hill.

That concept work like a repeater on top of hill. But for repeater station to work properly, it need to amplify it (to get it above noise and over come transmiter deficiencies) and then send it out again via transmitter antenna--as signal is too weak by itself to drive any type of transmitter and will get buried in the noise