[TowerTalk] 80 - 40 Meter Vertical Ideas

[RLVZ at aol.com]

Hi guys,

I plan to homebrew a combination 80-40 meter vertical to place at the edge of 
a saltwater river.   I am thinking of using one of the following options.  
Your thoughts would be greatly appreciated.

OPTION 1:  Use a 33' tower and extend a 33' length of aluminum tubing out of 
the top section giving a combined height of aprx. 66'.  I could insulate the 
tower from ground and base feed it giving me a 1/4 wave on 80 and a 1/2 wave on 
40.  I would then need to match the base impedence for 40 meters.  What would 
you recommend for matching the impedence?

OPTION 2: Use the same 66' structure as listed in Option 1 but ground mount 
the tower.  Have 2 shunt feed systems: one for 40 and one for 80.  Can I have 2 
shunt feed connected at the same time?

OPTION 3: Use the same 66' structure as in Option 1 but not only insulate the 
tower from ground but isolate the top 32' section from the bottom.  This 
would give me a 1/2 wave vertical dipole on 40.  When used for 80 meters I would 
use a relay to connect the lower and upper halves giving me a 1/4 on 80.  What 
would you recommend I use to switch in/out the two sections?

Ideally, I would like it set up for fast band changes.  (no time to fool 
around outside during a contest!)

Any recommendations at to which option would provide the best field strength, 
bandwidth, easiest match, etc. etc. etc. is much appreciated!

73, Dick- K9OM