I've used 75 ohm line for everything from repeaters to moonbounce. Years ago I used to make the quarter wave matching sections out of copper/brass tubing, and they worked fine. But for the last several years I just cut the line to provide low SWR. Assuming your antenna is close to 50 ohms, you can repeat that at the other end of a 75 ohm line by cutting the line to an exact multiple of a (electrical) half wavelength. I do this experimentally. For 2 meters I start with the line about 3 feet longer than it needs to be to reach wherever I want it terminated (one foot will do for 440). Once it is connected to the antenna I then start trimming it an inch or so at a time (at the other end) and checking SWR until it is very low (trim in smaller increments on 440 !!). Then use a random length 50 ohm jumper from the end of the 75 ohm hardline to the duplexer/radio or whatever. With this approach you can use either 75 or 50 ohm cable for a flexible jumper at the antenna end. Of course this only works on one band, but the same can be said of the quarter wave transformers! This method takes a little time and patience, but I haven't had a problem with it yet.
Paul N1BUG Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
