Experimenting with a DIY VHF Dipole

[Greekman]

So.... Assuming that a dipole has an impedance of 75ohm, which turns to 50 when it is made into an inverted V,

why shouldn't one make an inverted-V VHF antenna and then turn it 90 degrees for vertical polarization?





measurements

[Smurf Hunter]

Theoretically you should have a 1.5:1 balun between the dipole and coax. 

Also, I think as you get to higher frequencies, your dipole will be less broad banded, and its going to be difficult to get a low SWR across the entire 2 meter band.

We don't usually care about this on HF, both because of lower frequencies and we often have an auto tuner in line.

[Greekman]

yes, i know.
but the goal is to improve on the dipole SWR which is expected to be 1.5. Workable but it doesn't hurt to waste less power

[Carl]

add a couple more elements to the shield connected side and you have a ground plane....

[Smurf Hunter]

add a couple more elements to the shield connected side and you have a ground plane....

If you have a half wave dipole, why should you also need the ground plane?

[Greekman]

add a couple more elements to the shield connected side and you have a ground plane....

in fact i almost did. it so happened i watched a Kevin Loughin's (KB9RLW) suggesting the thing, the day before.

photobucket is acting up, so I will not be posting the pic yet

[Carl]

If you have a half wave dipole, why should you also need the ground plane?

I guess my humor was wasted. You really can't improve the SWR of a dipole without inducing LOSS to the antenna or feedline...1.5 to one is what you get and PLEASE PEOPLE ....remember that SWR is not an indicator of antenna performance any more than your autos 'oil' light is a gauge of RPM, SWR is a measure of the impedance match ONLY and a dipole is a 70 ohm antenna ,so the best you can get ,without inducing loss,is 1.5 to one...or we would all be using dummy loads for antennas.

[Smurf Hunter]

But I can spend a lot of money on a dummy load that gives a perfect 50 ohms any every band.

[Carl]

 

But I can spend a lot of money on a dummy load that gives a perfect 50 ohms any every band.

Yes ,you can.

[Greekman]

1.5 to one is what you get and PLEASE PEOPLE ....remember that SWR is not an indicator of antenna performance any more than your autos 'oil' light is a gauge of RPM, SWR is a measure of the impedance match ONLY and a dipole is a 70 ohm antenna ,so the best you can get ,without inducing loss,is 1.5 to one...or we would all be using dummy loads for antennas.

well my experiment was to find out if the impedance changes to a much favorable one

You really can't improve the SWR of a dipole without inducing LOSS to the antenna or feedline

Assuming that -as in my case- nothing changes other than the angle of the elements, where the extra loss would come from?
I mean is there any other kind of energy expenditure other than return and radiated power?