Where do the little AM guys hang out?

[K1JJ]

Yes, the RFI issues are very real when the legs get drooped down into the yard. Maybe because of proximity, ground effects or even some vertical polarization that is very prone to RFI it seems.

So in this case maybe the suggestion of trying the 57' dipole alone, flat on the top of the roof with masts is best.  I would suggest the 500'  #10 wire at Home Depot for the open wire and flat top.

Also, there is the perfect for you and simple homebrew antenna tuner design that consisits of just one capacitor and some copper tubing coil (HomeDepot)  that will handle 10KW, thus low loss for these types of antennas. Your tiny MFJ tuner may have problems being efficient on 75M with the low 10 ohms  -j2000 ohms that this ant will present.

Here's the article:
http://www.amfone.net/ECSound/K1JJ13.htm

Dave is correct that a 75M dipole that has its legs pulled down to the ground will be poor on the higher bands cuz the currennt point will be out in the center of the legs at times.

The bottom line is that if you use thgis high 57' long flat dipole, heavy #10 wire feeders and this homebrew tuner, your signal on all bands will be very close to a full sized dipole that is cut for each band... dipole figure 8 on 75M and 40M, 2 half waves in phase on 20M -figure 8, and a clover leaf pattern on 10M.  Not bad at all.  The 75M band is the real challenge cuz of the low impedance, thus the need for the heavy wire and beefy ant tuner. But 75M is where we get our our asses kicked around the most, so is the most important, caw mawn.

You've now got lots of ideas to work with, OM.

73,
Tom, K1JJ

[Steve - WB3HUZ]

Every situation is different.

I doubt a dipole with the ends dropping down will cause any more RFI than the vertical you are using now. It would probably cause a lot less.

I used a 75 meter dipole with vertical extensions hanging vertically off the ends and it worked well on 160 meters. I also worked well on the higher bands too. It's all a function of your feedline, the length and your tuner. I wouldn't worry too much about patterns if your antenna is going to be low to the ground.

And thus my previous message to experiment. Just because something worked or didn’t work for someone else, doesn't mean it will work/nor work for you.

[ne2d]

Thanks for all the advice, guys.
I'll have to think about it for a little while before coming up with an exact design, but I might try to put up a half-wave dipole or inverted vee for 75, if it will reach either vertically or horizontally at the ends. Then, if RFI problems are real bad, I can cut off the ends, so it's just a straight antenna.