I have been using exactly the setup you ask about for 4 yrs on 80m. I
have 2 Hytower verticals spaced 1/2 wave. I feed them in phase for
broadside coverage and 180 out of phase for end fire coverage. You need
to use 1/4 or 3/4 wave coax feedlines to each vertical to force equal
currents into them. The 2 feedlines are connected in parallel to your
xmtr feed line for broadside operation. For end fire you need another
coax line 1/2 wave long. It is inserted in series with the feed line to
one of the verticals and paralleled with the feed line to the other
vertical. If you simply parallel the feedlines, the swr will be ar;ound
2 or 3. I use it that way since my linear wil easily load into that swr.
A single relay can be used to switch the 1/2 wave line in and out.
If you use one 1/4 wave line and one 3/4 wave line to the verticals
then paralleling them gives you 180 degree phasing and adding a 1/2 wave
line in the 1/4 wave tower feed line gives you in phase broadside
operation. It is also possible to use a RF transformer to get 180 degree
phase shift.
Of course, you can match the pair of feed lines to your xmtr feedline
with LC networks but you will need 2 matching networks and additional
relays to handle the changes in Z with broadside/endfire switching.
GL and 73, Dan, N5AR
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