>>> There is a very acceptable range of impedance (ohms) that will work just fine for you. <<<
Right on! That's why Gawd (and the receiver makers) made antenna trimmer capacitors! <<grin>> In recieve only antennas, I tend to save a few bucks by designing around Mil surplus RG11/U coax (70 ohms to begin with) as the transmission line to feed them... not that it really makes a whit of difference in reception if you use 50 or 70 ohm coax. I used to make 50 to 70 ohm broadband transformers for the reciever end of the line, but finally decided it wasn't worth the trouble; most receivers, especially old ones, don't REALLY have a 50 ohm input impedance anyway, no matter WHAT the manual says! >>> If you want to split hairs (or ohms) then get an SWR meter or some form of analyzer and either adjust the length of your antenna to something near 50 ohms or use a tuner that can match the feedline and the antenna to 50 ohms. There are several possible ways to transfer power to an antenna in a ratio of 50 volts per ampere of current that many transmitters like to see. Transmitters manufacturers have chosen 50 ohms based on the most commercially available and popular transmission lines on the market with consideration to the many different antenna systems in use other than just a theoretical dipole. <<< Quite true... but with TRANSMITTING antennas you wind up with a different problem; ya ever seen a Bird 43 with a 70 ohm line section? In that case, 50 ohms is a sort of mandatory thing unless you keep a pocket calculator next to your Bird... so for transmitting antennas I go with the more traditional 50 ohm lines. It's just easier that way. I have to wonder about that tho; I'm a broadcast engineer, and in 3.125" hard line I keep encountering older stuff (mostly made by RCA) that is marked as 51.3 ohms!!! Never could figure out what's up with THAT! In any case... for receiving antennas, just don't sweat the entire issue. My ricebox TX doesn't like 70 ohm lines, but my boatanchor rigs don't even notice the difference; Valiants, DX-100s, and Globe King 500s will eat ANYTHING! Mr. T., W9LBB ______________________________________________________________ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
