[bars] 40M Dipole?

[Mike Raisbeck]

 Hi Willie,
A couple of observations:
1 - it doesn't need to be super straight.  any angle greater than 60 should do it.
2 - if you have choices on which point can be the highest, go for the center.  The center portion of the dipole carries most of the current, so the higher the better.

 3 - shoot for the middle of the band - it's a squeeze, but you might get most or all of the band at less than 2:1 SWR.  If you have a tuner on your rig, it hardly matters at this fequency

4 - depending on where your coax enters the house, you have the opportunity to base feed the whole thing as an 80m vertical
5 - might as well have a 20m dipole on the same feed points as well.  That way you get 20.  Though the SWR may be a bit over 2:1,  you will get 15m as well.
 
-----Original Message-----
From: William Smith <w_smith at compusmiths.com>
To: bars at w1hh.org
Sent: Thu, Sep 3, 2020 7:11 pm
Subject: [bars] 40M Dipole?

Hi All,
As I mentioned last night during the Zoom meeting, I'm looking at building a 40M dipole out of some wire, insulators, and an SO-239 connector, using essentially the instructions at:
https://dcasler.com/2011/02/17/ham-radio-40-meter-dipole-your-first-antenna/
I'm hoping to stretch it out across the roof peak of my house, which has lots of space:

The ridge of the larger side is 40 feet, and the smaller side is 25 feet, so 66 feet ought to be do-able.
I have a couple of questions for the experts:
1) Does it make much difference if the antenna is straight?  I might do something like:

To stay away from the ridgelines, where I know there's a lot of wiring (the point of the "Vee" is where I have a couple of antenna poles.)
2) Obviously I want to start out long and shorten the wires, so as to avoid the "I cut it three times and it's still too short!" problem, but I'm not sure if I have to cut the (insulated) wire at the ends, or if I can wrap it back around itself (which would allow me to lengthen it if I overshoot).
3)  Should I aim for one end of the band or the middle?  Or is it going to be pretty good throughout the band?
Is there anything else I should know before I start?
Many thanks in advance!
73,
WillieN1JBJ
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