KDX-FM New Transmitter Site

You are obviously experiencing signal absorbs-ion from trees, even if you have an antenna 10 feet away from your transmitter it will effect FM in ways it won't effect AM. so I suggest you get your TX as high as possible and no metal objects anywhere near it.

Some folks with Ramseys have used outside antennas and even at low power 1mW to 25 mW if done right could get you out an entire neighborhood. Also many folks transmitting considerably HIGHER POWER have this same issue when it comes to objects close to your antenna. It even effects your SWR as well.

Radio Brandy is selling a modified Workman SWR-3P meter that covers lower power levels than 1 Watt for FM so you can actually see what your SWR is. The lower your SWR even at P15 levels the better your range is. Your signal will also be more stable.

This is why I always have said under the correct conditions you can go further than 200 Ft legally but it requires homework. Good Luck with your FM project.

New Period of Development

Thanks for your good input TheLegacy.

I'm going to investigate whether the translator on my channel is legal, as previously I was in the exact triangular fringe of three college stations. The translator is gospel music rubbish.

Also I'll look into that new RF device from Radio Brandy.

Your comments about antenna placement are correct and I agree with them.

EDM Transmitter in Service

For KDX this is a time of FM development.

The previous use of FM as a studio-to-transmitter link has been discontinued.

As of this past week FM is the official monitoring medium at our control desk, where we have the on air signal and a production channel on two different frequencies.

Based on Tim in Bovey's inspiring EDM Transmitter Review at part15_us we have ordered the same model he talked about, EDM-LCD-CS-EP.

We have taken an interest in using all horizontal dipole antennas for FM transmission.

It is appealing to us that the signal can be aimed directionally in two opposing directions and the side lobes being nulled out, which will focus the signals on the length of our campus while casting little signal toward neighboring buildings.

First problem with horizontal is physical structure and placement. Unlike a simple whip standing vertically, a horizontal wire or metal piece must be held firm along it's length.

It seems reasonable that a horizontally polarized signal will perform better indoors, where room sizes are wider and longer than floor-to-ceiling ratios. This has not been proven or mentioned elsewhere, but we will believe it until we know otherwise.

All comments on these thoughts will be much appreciated.

Taken Into Account

DavidC: "With a horizontal dipole, you'll lose a great deal of signal on the receiving end unless that antenna is correctly polarized (i.e., horizontal as well)."

Luckily all applicable receivers are capable of having their whips rotated into horizontal position.

In some cases that might pose the problem of having antennas sticking into inconvenient locations. Another design problem.

If I find that horizontal is not provably better than vertical in an indoor environment, it will be vertical from then on.

Antenna Choices

TheLegacy suggests: "What about citcompolar antennas or folded dipole antenna for indoor flycasting or yard casting at 11 nanowatts?"

Don't we wish.

I have never had experience with anything other than straight wires and whips.

Got to build or buy some curvy multi-polar antennas for test purposes.

As DavidC mentioned, we may want to put slicker antennas on our radios at the same time.

Indoors is a strange place when it comes to FM signals.

Hey, maybe the antennas should be outdoors?

Paid a lot less for my Outside Ground Plane antenna. However could be nice for apartment dwellers who are not allowed an outside antenna.