Lou,

That's exactly what I'm thinking of putting up here.  Did you you feed the coax directly to the dipoles or through a balun?  Can't decide on which way to go
with that.

73

Don  W6SMB

On Sun, 30 Jan 2005 17:30:17 -0500, Louis Kim Kline wrote:

Hi Keith.

Feeding two dipoles from the same feedpoint works, and it can be quite
painless if you keep everything at right angles because there is virtually
no coupling between the dipoles when they are placed at right angles to
each other.  I haven't the space to do 160 meters, but when I had 80 and 40
meter dipoles set at right angles and fed with coax, the combined load from
the two dipoles put the load within range of my auto tuner everywhere from
80 meters through 6 meters.  Pretty versatile.  Admittedly, the efficiency
wasn't terrific on some of the WARC bands, but it actually gave a darn good
account of itself and did as well as my multiband vertical.  I had mine
strung as inverted vees.  That might make a difference for multiband
operation, as it tends to lower the feedpoint impedance, which may help to
put the load within range of the tuner on some bands.

On the system that I used, the vees were strung off the top of the mast and
served two purposes:  they served as the radiator, and when properly
tensioned, they also served as the guy wires for the mast, making the
antenna system very stable in high wind conditions.  Aside from a major ice
storm, I found this antenna to be very rugged in bad weather.

The one element was cut for about 3820 kHz, while the other one was cut for
7100 kHz.


73, de Lou K2LKK




At 09:54 PM 1/30/2005 +0000, you wrote:
>Hi all,

>Wonder if any one has compared the doublet fed with open wire line to
>dipoles cut for the required bands.

>My two bands of interest are 160 and 80 metres.  I am using a doublet
>with a top of around 230 feet.

>I was talking to a friend today with a similar setup on 80 metres.  He
>went and cut the extra ends off and made it 132 feet in length and his
>signal was reported some 10 db improved.

>So, I am concluding that it is possible for a doublet to be too long and
>the old saying to get as much wire in the sky is not always true.

>So, just wondering if anyone has made meaningful comparrisons
>between the doublet and dipoles.  What about the F7FE idea of feeding
>more than one dipole from the same feeder?

>My activity is devided between the two bands and I do not need the
>aerial to work on any other band.  I had thought of traps but I use a high
>power linear and would not wish to melt them.


>Keith

>- -

>Keith Barrett


>gw4nby

>Bridgend
>South Wales

Louis Kim Kline
A.R.S. K2LKK
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