drums114 Posted December 24, 2013 Share Posted December 24, 2013 I want a radio antenna for the EDM transmitter instead of the little wire that they give you for my 2014 display. What are people using to plug into the RCA antenna plug in the unit? I am sure there is a radio antenna that is made to plug into that RCA connection....let me know. Link to comment Share on other sites More sharing options...
a31ford Posted December 26, 2013 Share Posted December 26, 2013 I used a chunk of RG-59 U with a TNC end, and then a TNC to RCA adaptor, I measured the length of my frequency 11188 divided by 91.1 = 122.81 inches, then divided by 12 and got 10 feet 2.81 inches. this is the "multiple" length (or one can the 122.81 times whatever to get a total length) and THEN, cut the outer shield 122.81 inches from the FAR end, there by creating an ungrounded (or un-shieled) section. This section is the antenna, the rest is the feed cable TO the antenna. I ended up using 64 some odd feet (this way the antenna is up the side of my 80 foot tower, just NOT all the way up). I used a couple of short chunks of grey PVC pipe as Antenna mounts and mounted the unshielded section vertically between them. I get a total of 4 miles (2 in any direction) off a 200mw EDM this way. HOWEVER, the director is currently in the basement, and we have a couple RG6 cables that go up to the tower, so currently I've got the EDM there, and running the mismatched cables to the antenna. I need a pair of "audio line drivers" (see my post in the hardware section, accessories, "remote transmitter" ) and have ordered parts to build a stereo pair of drivers and receivers, this way I can place the EDM back out at the tower. http://forums.lightorama.com/index.php?/topic/30395-add-on-remote-300-feet-fm-transmitter/ Greg Link to comment Share on other sites More sharing options...
George Simmons Posted December 26, 2013 Share Posted December 26, 2013 Try this one: http://www.hobbytron.com/Tru-Match-FM-Broadcast-Antenna-Kit.html I've been using it for the past five years and it sounds great! (You'll need a patch cord between the amplifier and antenna.) Link to comment Share on other sites More sharing options...
drums114 Posted December 27, 2013 Author Share Posted December 27, 2013 What is it? What is in the PVC? Link to comment Share on other sites More sharing options...
Surfing4Dough Posted December 27, 2013 Share Posted December 27, 2013 I get a total of 4 miles (2 in any direction) off a 200mw EDM this way. GregYou must have a very bright display if people can see it from that far away. 1 Link to comment Share on other sites More sharing options...
a31ford Posted December 27, 2013 Share Posted December 27, 2013 LMAO @ Surfing..... wana see it ? Greg Link to comment Share on other sites More sharing options...
a31ford Posted December 27, 2013 Share Posted December 27, 2013 What is it? What is in the PVC?It is what is known as a dipole, they most likely are using a simple wire arrangement, I do like the PVC as an insulator AND weather proofing.... I simply used a chunk of cable myself. Greg Link to comment Share on other sites More sharing options...
dgrant Posted December 27, 2013 Share Posted December 27, 2013 This year, I cabled up a two meter HRT antenna and it seems to tune just fine. Now I don't own an SWR meter to be sure its working as well as it should but so far, nice clear/clean signal at the minimum power on my EDM-RDS. I'm not looking for distance, rather clean signal here within a couple of blocks of this house and not past that. Link to comment Share on other sites More sharing options...
drums114 Posted December 28, 2013 Author Share Posted December 28, 2013 So if I wanted to make my own folded dipole antenna and broadcast on 88.7 FM, I should make the lambda 43 inches then fold that in half? How long should the wire be then to the transmitter? 86 inches? Is that right? I plan on making this from some old coax cable I have with some zip wire. Link to comment Share on other sites More sharing options...
a31ford Posted December 28, 2013 Share Posted December 28, 2013 One full wave for 88.7 Mhz is 11188 divided by 88.7 which equals 126.1303 inches So diggind into my "how to build a dipole pages I come up with this.... 31 and 11/16 inches for each portion (top and then bottom (hot and earth, respectively)) Here: http://www.radiobrandy.com/dipole1.html note the balun.... IMPORTANT ! and that the top connector is center only and the bottom is shield only. Greg 1 Link to comment Share on other sites More sharing options...
drums114 Posted December 30, 2013 Author Share Posted December 30, 2013 so 31 inches up and 31 inches down on the loop? How long should the wire going to the transmitter be then and what should be the lamp cord length? Link to comment Share on other sites More sharing options...
a31ford Posted December 30, 2013 Share Posted December 30, 2013 Sorry, I should have clarified myself. the Dipole is ( 31 and 11/16 ) for each element (hot and shield). the loop makes a "Balun" and is only 3 turns of a 6" loop of coax . Gregthe length of each element is critical for distance Link to comment Share on other sites More sharing options...
a31ford Posted December 30, 2013 Share Posted December 30, 2013 So, to review the Dipole Greg Link to comment Share on other sites More sharing options...
drums114 Posted December 31, 2013 Author Share Posted December 31, 2013 Hi Greg - Sorry I am just learning all of this now. I am confused, I was going to make your antenna using coax and lamp (zip) wire like in your youtube video. So the lamp wire needs to be 31 11/16 inches total? Link to comment Share on other sites More sharing options...
a31ford Posted December 31, 2013 Share Posted December 31, 2013 It's Not my video, but looks like it would work. correct for your frequency of 88.7 Mhz, EACH one..... The shield is one, the centre wire is another. SO end to end is just under 64 inches (31-11/16 x 2). Greg Link to comment Share on other sites More sharing options...
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