Doug Smith <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---------------------------------------------------------------------- > I think a 4:1 balun would be more appropriate. I think that is what the > balun for the MN-2000 had as an option from Drake.
Well, yes, it *might* be more appropriate. Or not. Depends on whether the antenna is short or long on the various frequencies of interest. If it's short, then a 1:1 would be a better choice. A short antenna presents a very low resistance and running a 12 ohm antenna (not unusual) through a 4 to 1 transformer is going to be hard to match with any tuner. If it's always long then a 4:1 might be better. Also, the length of the feedline makes a difference. If it's a length that would effectively transform low and high impedances into moderate impedances then a 1:1 would be better. If the feedline is near an even multiple of a half wave at any F/O then a wider range of high / low impedances will be encountered and either a 1:1 or a 4:1 might work, or not, depending on the frequency. And, finally, I must point out that there is a credible school of thought that suggests that using a balun on the reactive side of a tuner is not the best design. Apparently, baluns tend to work best at their design impedance, losing efficiency as the reactive component of the circuit increases. Certainly, any balun so placed should be *way* overrated to minimize losses. If it were me, I'd go with a feedline of 31 or 93 feet long (assuming an open wire feedline velocity factor of 0.88) and use a BIG 1:1 balun. But, it's not me and this advice is worth no more, and maybe less, than what you paid for it.. 73 and see ya on the air! -Doug, W7KF ---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
