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FM Transmitter question


oj70chevy

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I bought the EDM-RDS and it works so far. I've not had a show yet as this is my first year. I have it set in the lowest possible setting of 1mw as I don't wish to cause problems or visits from the FCC. Doing so, I've noticed that at the curb, my new CTS, picks up the signal just fine and the RDS data works perfectly. Now other cars here, tend to pick up a less than stellar signal with more noise. I need to find a comfortable medium that won't get me into trouble and yet still work within few hundred feet of the front lawn. Antenna to street distance is about 75 feet or so.

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dgrant wrote:

I bought the EDM-RDS and it works so far. I've not had a show yet as this is my first year. I have it set in the lowest possible setting of 1mw as I don't wish to cause problems or visits from the FCC. Doing so, I've noticed that at the curb, my new CTS, picks up the signal just fine and the RDS data works perfectly. Now other cars here, tend to pick up a less than stellar signal with more noise. I need to find a comfortable medium that won't get me into trouble and yet still work within few hundred feet of the front lawn. Antenna to street distance is about 75 feet or so.


That's great. Sounds like just a quick game of trial and error as you bump it up a little at a time.
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dgrant wrote:

I bought the EDM-RDS and it works so far. I've not had a show yet as this is my first year. I have it set in the lowest possible setting of 1mw as I don't wish to cause problems or visits from the FCC. Doing so, I've noticed that at the curb, my new CTS, picks up the signal just fine and the RDS data works perfectly. Now other cars here, tend to pick up a less than stellar signal with more noise. I need to find a comfortable medium that won't get me into trouble and yet still work within few hundred feet of the front lawn. Antenna to street distance is about 75 feet or so.

Make sure you test with different positioning of your antenna. If using the included wire antenna, mount it vertically (at least that is what I found worked best with car radios).
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If I remember correctly, AM rf energy travels vertically and FM rf runs horizontally. I'll try the vertical just in case. Thanks.

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dgrant wrote:

If I remember correctly, AM rf energy travels vertically and FM rf runs horizontally. I'll try the vertical just in case. Thanks.


FWIW, I read somewhere that it's best to orient the transmit antenna in the same way as the receive antenna. Since vehicle antennas tend to be oriented vertically, I orient my transmit antenna the same way. Good luck.
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Guest wbottomley

dgrant wrote:

If I remember correctly, AM rf energy travels vertically and FM rf runs horizontally. I'll try the vertical just in case. Thanks.


So what happens if your transmitter's antenna polarity is circular?
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Aaron Maue wrote:

dgrant wrote:
If I remember correctly, AM rf energy travels vertically and FM rf runs horizontally. I'll try the vertical just in case. Thanks.


FWIW, I read somewhere that it's best to orient the transmit antenna in the same way as the receive antenna. Since vehicle antennas tend to be oriented vertically, I orient my transmit antenna the same way. Good luck.

Exactly.
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wbottomley wrote:

So what happens if your transmitter's antenna polarity is circular?

In that case, for best reception, you'd need to drive in circles. This approach is definitely NOT RECOMMENDED if you live on a narrow street.
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George Simmons wrote:

wbottomley wrote:
So what happens if your transmitter's antenna polarity is circular?

In that case, for best reception, you'd need to drive in circles. This approach is definitely NOT RECOMMENDED if you live on a narrow street.

Only works well if you live on a cul-de-sac.
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dgrant wrote:

If I remember correctly, AM rf energy travels vertically and FM rf runs horizontally. I'll try the vertical just in case. Thanks.
LOL thats a good one. Should keep the newbies scratching their heads for a bit. :cool:
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Maybe I'm messed up, but as I'm thinking or remembering, FM runs in horizontal waves out across the earth from the transimitter antenna. This is why most FM car antennas and receivers have dipole antennas designed to be mounted horizontally. Now AM will travel in vertical waves from the surface to the top of the atmosphere, again from the transmitter antenna which is always vertical. The old OEM car antennas were always just sticking up off the fender vertically for this reason.

Now saying all that, the EDM FM Transmitter has a single wire for an antenna therefore no proper dipole so mounting it horizontally or vertically, I vote for whatever works best in the given installation.

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I've installed a FM station antenna and the are absolutely horizontally polarized. Boy was it fun being on a 100' tower with nothing keeping you there except your safety belts because you've got both hands working the antenna.

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Guest wbottomley

dgrant wrote:

Maybe I'm messed up, but as I'm thinking or remembering, FM runs in horizontal waves out across the earth from the transimitter antenna. This is why most FM car antennas and receivers have dipole antennas designed to be mounted horizontally. Now AM will travel in vertical waves from the surface to the top of the atmosphere, again from the transmitter antenna which is always vertical. The old OEM car antennas were always just sticking up off the fender vertically for this reason.

Now saying all that, the EDM FM Transmitter has a single wire for an antenna therefore no proper dipole so mounting it horizontally or vertically, I vote for whatever works best in the given installation.


I'm laughing myself ignorant here.
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Indoor_TV_Antenna+rabbit+ears.jpg

I use one of these,I can transmit one vertical one horizontal and one circular. look in the middle it's even lor approved
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dgrant,

Do you understand the radiation pattern of a vertical antenna and a horz antenna? Vertical is omni direction and a horz antenna is known as a beam. I highly recommend you go and do some reading.

Timon, your so bad..

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lol its called a moonraker cb antenna my dad had one back in the day he talked what thay called" skip"the radio signals would bounce off of the earth and the ionosphere and you could point this thing towards japan and talk to Europe no it wasn t legal but it was fun as ----

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amazing what one can find when googling images.

To quote my friend mr bottomley: "i'm laughing myself ignorant here".

I'm sure you know William, as you're both from the Carolinas..he probably helped you out a lot in the past...?

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