lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> >> I was just mounting my ELT and noticed that it needs an antenna that appears to be identical to my com antenna. has anyone split the com antenna and used it for the ELT as well? also, do the "whip" antennas that come with ELT's need a ground plane to operate in a composite aircraft?<< Scott, The ELT antenna is identical to a Com antenna, not surprising when you remember that an ELT is just an automatic transmitter on a VHF Com frequency of 121.5 (the new ones also transmit on UHF Guard, 243.0, so one or the other frequency is not optimized). Sharing an antenna could be done, but you have to have a "spiltter" that can handle transmitters. Typcially, the splitters you see are for recievers only. If you use one of those, your Com radio will damage your ELT or vice versa. This happens because the splitter has in effect directly connected one transmitter to the other reciever and sent it way more RF power than it was designed to handle. The type of "splitter" you would need is available. They are called something else, like "coupler", and cost considerably more. Lastly, the antenna that came with your ELT would need a ground plane, or you could use a dipole like many builders use for Com antennas. - Doug Dodson Glasair II-S FT Flight Test Engineer, CFI-A,G Baby Dragon IF1 Race Team >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>