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Need antenna for a edm trnsmitter


THolland
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All that is, is a 36 inch length of stranded wire soldered to the tip of a RCA phono plug.

If the wire pulled loose from the plug, just resolder it, or a tv repair shop could do it for you in about 30 seconds.

If it's that some of the wire is missing, then just get some more stranded wire, strip the ends and either solder or just twist it together. Make sure the final length is approx 36 incheds

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Ok I may be able to soldier it back together it broke about 6 inches from the plug. I guess I can strip a little insullation back half inch or so and try that. If that does not seem to work does Radio shack carry something that I can replace it with and it work properly?

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Good news it seems to work after I soldier it back just have to check the range now. Thanks for all the help here in LOR land. I got to run my show for the first time to test somethings and I think the show will go on schedule for either Friday or Saturday night. Thanks again for everything and for being some of the most helpful people in the tech support realm of things.

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I don't know how to grab a link for an old message I posted about antennas, using the little test whip provided by EDM for your full time broadcast isn't really a good idea for a number of reasons. Here is a post from a few years back:

Hi All,

Antennas are not magic, and you can dump a boat load of money to buy one that you can easily build on your own - on the cheap and achieve the same results.

Linda - unplug the rabbit ears and never use them again - you can burn up your transmitter (in RF talk the Voltage Standing Wave Ratio (VSWR) can bounce back so much energy as to burnout the final stage amplifier).

Here is a link to a site that walks you through the construction of an open half wave dipole antenna: http://braincambre500.freeservers.com/open%20end%20half%20wave%20dipole%20antenna.htm

If you had to buy everything - maybe $10, and you'll probably have to turn down the power of your transmtter.

Since Linda provided the specifications for her radio: Output Impedance : 50 Ohms she should use rg-58 (50 Ohms) instead of rg-59 (75 Ohms). I would also recommend using solid copper wire (12 or 10 gauge) instead of wire hangers...

Steve

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I too have read that the included piece of wire antenna that comes with the EDM should NOT be used as a permanent antenna for it.
I came across this diagram for a simple dipole that doesn't require much more than a piece of RG-8 cable and a short chunk of wooden broomstick to make.
I built one for my EDM 2 years ago and it works great at the 87.9 frequency I am using.
I do have a very nice one that I purchased from Dennis Cherry that will go outside on a permanent pole mount one of these days but it is made for the 100.7 frequency and I have not gotten around to switching my voiceovers and things yet!
I took the ende of the cable and crimped on closed lugs (terminals used for wiring) so I can put the antenna up on an inside wall of my house using two thumbtacks to hold it and works great. I can get 1/4 mile distance easily on the low setting.

Attached files 283877=15754-EDMdipole1.gif

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The "Test Antenna" that comes with the EDM transmitters will not damage the transmitter.

The EDM is designed to safely tolerate a VSWR of at least 20:1 without damage (unlike other brands).

Using a SWR meter that is designed to cover the freg range of 88 - 108 mhz, and doing measeurements at several different frequences across the FM band, using the EDM supplied "test antenna", I found a low of 2:1 and a high of 7:1, all safely within the factory designed tolerances for this unit.

My comments apply only to the EDM, other transmitters may croak with a VSWR of only 3:1.

When trying to build your own antenna for use with any transmitter, I strongly suggest you have the appropriate test equipment for measuring VSWR and making the proper adjustments.

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As always, John is most correct on the issue.

I had only read that it was not good to use the included wire antenna for long periods of time but it is a better idea to use the proper test equipment or get someone who works on this type of equipment to test for you and make only things which can be "verified" as working correctly with whatever transmitter you are using.

My diagram for the simple bipole antenna to replace the wire was located on a radio hobbyists site. As is, it works for me (although I do not remember the exact VSWR that I get with it right now) and I did test it with my transmitter before I put it into use.

In short and as John pointed out: Take the time to do it right and CHECK things to be sure. You will only make things that will last and not be a cause of headache later on.

Thanks John for correcting my "lack of content" about things.

I should have had my "second cup" before posting! HA

Bill

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