EDM-TX-LCD Transmitter Antenna

[Brad Fryar]

I purchased an EDM-TX-LCD transmitter last year and used the wire antenna provided with fair results. I'm now looking to upgrade to an exterior antenna...where can I locate one that has a proven track record.

Also, my transmission last year was very heavy on bass, can that be attributed to my wire antenna or just a basic lack of understanding the initial set-up of the transmitter ?

I appreciate any help.

Brad

[Richard Hamilton]

Brad Fryar wrote:

I purchased an EDM-TX-LCD transmitter last year and used the wire antenna provided with fair results. I'm now looking to upgrade to an exterior antenna...where can I locate one that has a proven track record.

Also, my transmission last year was very heavy on bass, can that be attributed to my wire antenna or just a basic lack of understanding the initial set-up of the transmitter ?

I appreciate any help.

Brad

Brad, I don't have the EDM TX in my hands yet, so I am not sure about what kind of antenna connector it has, but I will mention that the most important thing to keep in mind is to make sure your antenna impedence is matched to what is expected by the transmitter. From the written specs, it appears to want a 50 Ohm load which is fairly common, so get a antenna with a 50 Ohm load to match it. Otherwise you might get accidentially mismatch it with one that is 75 Ohm which is also a common standard out there. The best performance will come from matching the load to the transmitter and run less risk of a high "SWR" from reflecting back into the transmitter to damage it.

Also use matching coax, especially if you have a long cable run. The type of antenna is less important in my opinion because we are talking about short range, lower power transmission.

Regarding the "Bass" thing... no, that is highly unlikely to be a transmitter issue. It is more like having wrong settings on the mixer output of your computer. Adjust those settings.

[pdowns]

There are a zillion good antennae to choose from. I can assure you they are all better than the simple 1/4 wave wire antenna that came with the EDM-TX-LCD transmitter. I don't think they really expected you to use it. It's just there to let you play with when you open the box.

The benefits of a better antenna will be longer range and some sound quality improvement since less energy will be reflected back in to the transmitter which degrades the sound quality. Personally, I would stay away from 1/4 wave verticals like telescoping wires, etc.

This year I will be using this antenna:

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=TM100


As to your question about your sound having too much bass. That is not caused by your antenna. Is it possible you are confusing bass with distortion? Try turning down the PC volume. Turn it down a bunch. You might be surprised at how much that will improve your sound quality.

[Steven]

A heavy bass in an FM transmitter could be caused by the pre-emphasis being set wrong. In North America the pre-emphasis is 75 µs, where in the rest of the world, it is 50 µs. If you are using a transmitter set to 50 µs, and listening with a North American FM receiver (set to 75 µs), then the lower frequencies will sound louder.

I can't visualize how the antenna could make any difference.

[Richard Hamilton]

pdowns wrote:

This year I will be using this antenna:

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=TM100

That is the same antenna I have been using for the last 2 years. I really like it!

[Steven]

Here's the antenna I'm using:


Attached files

[Steven]

And here's a close up. It's made from brass rods, soldered, welded, and epoxied to an SO239 connector, then set in a PVC pipe, which is glued to a vent on the garage roof.

I don't have it in the attic because we have a metal (steel) roof.


Attached files

[Brad Fryar]

I appreciate all the helpful information and the link to the TM100 antenna. Looks like I've got some work to do on this end. Gotta love Pink Floyd!