[TowerTalk] Re: Feeding 2 Inv V's with 1 feedline

[Pete Smith]

At 01:32 PM 1/26/04 -0600, Didier Juges wrote:
>If both dipoles will be used in the CW portion, I would tune the 40m dipole
>first. Considering that the 80m dipole should have greater impedance at 7
>MHz than the 40m dipole at 3.5 MHz, the 40m dipole will have greater
>parasitic effect on the 80m operation, so you should probably adjust it
>first. Now, if you want to tune the dipoles up in the band (such as the SSB
>portion), or one CW and the other SSB, it makes probably less difference.


For many years, my main antenna system was three inverted vee dipoles off 
the same feedpoint, hung in a tree behind our townhouse.  Separate dipoles 
for 10, 20 and 40 meters, the latter with W9INN coils to extend them to 
cover a segment of 80.  As long as the dipoles were arranged so that they 
were not too close to each other (rotated 20 degrees or so from one 
another, as viewed from above), I saw very little effect from changing the 
length of one on the tuning of the others.  Changing the included angles of 
the individual dipole pairs seemed to have a much larger effect on their 
resonance and feedpoint impedance than anything that was done to the other 
ones.


73, Pete N4ZR
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