I know this has been discussed a bit in this NG. There is a
surprisingly small amount of information in my antenna books regarding
the spacing of HF antennas. I currently have a full wave 40 meter
vertical loop and much to my pleasure it works great. It's built
exactly the way one of the ARRL antenna books describes it.

I would also like to set up two 80 meter inverted V's in a HUGE pine
tree about 100' from the loop. The two V's are for greater directional
coverage and will have their own coax feed lines. I have a pretty good
antenna tuner so I may have to run the inverted V multi-band if space
is a problem. I also have a 10 meter rigid dipole that I would like to
hang vertical. Finally, the "antenna farm" will include a fan dipole
for 15 and 20 meters.

I haven't been able to find any firm rules regarding the spacing of the
antennas. I assume a full wave length will be enough. Unfortunately,
there may not be enough space for that.

Are there any "rules of thumb" I can follow for adequate antenna
spacing? There will never be more than one antenna in use at a time
with perhaps one exception of an additional receive only antenna for
the shortwave. I'll be getting my General class next month and am
chomping at the bit to get this stuff up! :-)

Thanks!

Any antenna will couple to some extent to another, especially if on the
same band... I have modeled my 80 meter antennas with spacings in
excess of 1000 feet and they still distort each others pattern... I use
relays to detune the unused antennas...
Now, your inverted vees at right angles on the same support will work
OK... I don't know that there will be a big difference in patterns, I
suspect less than a half S-unit at best... But try it and let the group
know your results...
There will be less couplilng between antennas on different bands and
while there will be some pattern distortion what you lose in one
direction you will get back in another... I would hang the antennas and
go for it... Drop us a line when you are ready to go and we can make a
sked to work you on 80...

denny / k8do