I have an R7 up for 40-10. Two maple trees on the property, one in the
front yard and one in the back but not far enough apart for an 80m
dipole. The trees runs east west over the house. I would prefer to run
the dipole north south, using the backyard maple for a support. The
lot at this point is 66' wide. One other thing to mention I don't
think I can run ladder line or open wire feeder into the house. I am
pretty much limited to coax.

Thanks for the help,



I just got done building a "shortened" 75M dipole for traveling. It
is 27' on each leg. Homemade coils are out from the apex 15'. Doing a
little research in some old antenna books, and on web, I found good,
easy, information on calculating the value of the coils, depending on how
far out from the apex you want. In my case, I needed 50uH coils, which I
wound on some 1.5 inch plastic pluming material with #22 close spaced
telephone house wiring. For my little 5W FT-817 this works quite well,
but if you are running more power, you'll need to build a bit more robust
coil. Apex is held up with one of those 23' RV telescoping fibreglass
flag masts.

While open ladder line feed would give you a lot more flexibility, if
you must use coax, then what I did sure would be an easy thing to do. If
you need coil computation data and can't find it yourself, email me and I
will try to get it to you.


Ed K7AAT Email: Frog850 AT Bivalley.net