> was wondering couple things. If I make a full quarter wave vertical WIRE
>in tree 65 feet tall and see DX Engineering verticals claim 65 foot tall
>but wider bandwidth. What is their secret or just advertisement?
I don't know the DX Eng. product. Usually "wider bandwidth" means
flatter vswr cur
Mike, a different question than you asked, but if you have two trees or other
supports at 65 feet or greater and more than 130ft apart, I think an 80M dipole
strung between them will be a better all around antenna than a vertical. If you
can get to 80ft or 100ft the dipole was be markedly better
Hi Mike, et al,
Here are my thoughts interlaced.
> Hey Topbanders,
>
> I was looking to buy or make a mono type 80 meter antenna for DXing.
>
> I was wondering couple things. If I make a full quarter wave vertical WIRE
> in tree 65 feet tall and see DX Engineering verticals claim 65 foot tall
The larger the diameter of the antenna, the broader the bandwidth. So an
aluminum self supporting vertical that starts with 3" diameter tubing
(the HD DXE starts with 4") can have twice the intrinsic bandwidth of
16ga wire. It also gets a bit shorter for same resonance frequency. I
had a guy
Hi all -
Assuming a standard 1/4 wave vertical is 36 ohms - is there any formula that
will calculate the Z if the vertical is short and brought to resonance by top
loading wires - I understand the Z will be less - but how much by ? I am trying
to use the formula on ON4UN disc to calculate the a
Eznec is your friend Dave. Having used a previously short Vertical 51ft for
20+ years, the top loading is not your problem. Because the feed Z is low you
will require longer radials. Mine are typically 0.4 wavelengths.
I will stand corrected but the formula is E (efficiency) = Feed Z/ Feed Z p
Hi Dave,
There is a very accurate formula to calculate radiation resistance of
vertical radiators that are 1/8 wavelength or shorter in physical length
that's in the ARRL Antenna Book, and this formula provides values very
close to those you would obtain using 4nec2 (you could use this formula to
