Isn't this a Vertical dipole? Two quarter wave radiating elements? And
tower behind it will be some kind of reflector/director depending on
height. The radials seem unimportant if thought of this way.
Antennas radiate because of the current flow.
So you would have two current maximums, one
Tom and all,
If I am reading the question correctly, aren't we talking about something that
is done at VHF/UHF with great regularity? Stacked vertical elements, stacked
vertically polarized beams and all manner of stacked vertical anything are
done there all of the time to avoid cross
Hi, Mike
When you say that you use stacked vertical beams - aren't they stacked
horizontally?
It seems to me that the vertical collinear elements,along the lines of what
Carl is describing, are generally vertical collinear 1/2 waves in phase -
usually with a 1/4 wave phasing line between
Well, if I understand Carl's proposed antenna - he is proposing enough
vertical height for two 1/4 wave ground plane antennas, one above the other.
In that case I would elect to use a vertical dipole. That would place the
current maximum at least a 1/4 wave above ground - reducing the ground
Tom,
Fully understood. I wasn't referring to the usual collinear antennas sold by
comet or anything of that nature. I am referring to the stacking arrangements
used for ops like moonbounce, etc. As far as the design theory (and practical
application) goes, I have a reasonable amount of
Oh, I didn't address one comment you made, Tom.. 5/8ths are dogs on 160?
Really? That is odd in the extreme to me. I had incredible success with a
ground mounted 5/8 on 20 meters while I was stationed in Hawaii. I was rather
space limited, so I could only go up and a tower mounted beam
Oh Tom, I FULLY agree that it would be VERY difficult and not very practical,
especially considering we are talking 160.. In fact, the price/performance
ratio simply wouldn't be worth it, in my own humble opinion. no doubt about
that.
There are certainly better ways to get ALOT more
On 09/06/2013 04:13 PM, Edwin Karl wrote:
There are several interesting articles if you Google Franklin Antenna
they are mechanically BIG and require feeding ingenuity (hams are known
for this feature ...) but are stacked verticals, note- phase the top
element
to avoid cancellation.
If memory
Guy, I was right across from the small marina you see. The difference I am
talking about is the difference between a 5/8ths wave vertical and a quarter
wave vertical in the same place. I am not talking about the difference between
a vertical next to the sea as compared to a vertical in
Guy, you aren't reading my emails.. because that question is not
appropriate to the conversation. I am NOT, I repeat NOT talking the difference
between LOCATIONS, but the difference between ANTENNAS AT THE SAME LOCATION! I
am NOT talking about RURAL ANYTHING. That location being on Gannet
Like Tom said earlier, it's all about ground loss. Near the sea, a 1/2 or
5/8 wave vertical may perform very differently than a duplicate antenna a
long way from the sea. The near-field and far-field losses at the lower
angles would be much lower.
73, Mike
www.w0btu.com
On Fri, Sep 6, 2013 at
On two meters, yes indeed. But we are talking about 160. To quote Tom above:
Also, for 160, antennas are near earth. Earth spoils everything. A 160
antenna at 260 feet is like a two meter antenna at 3.25 feet above ground.
... This is 160. The distance ratio for the same behavior on two meters
Mike, you are answering the wrong question. Guy didn't understand the question
at all. I KNOW that sea water is a better ground than dirt.. The
comparison I was ALWAYS talking about had NOTHING AT ALL to do with LOCATION!
NOTHING! The comparison was a quarter wave vertical compared to a
What got my attention was seeing what appears to be stacked groundplanes at
the Manchester NH airport.
I dont want a collinear or vertical dipole.
The basic ollinears are 2 half wave elements fed at the center either
vertical or horizontal and go back to the 30's for SWBC and some ham use. In
I find SNR reports from RBN very useful and RBN a great tool, but you have to
understand the numbers and what they really mean. Let me explain that with a
real life example.
Almost all skywave HF signals are affected by amplitude fading which follows a
Rayleigh distribution when plotted
Gee, I wonder if Carl had any idea what a catfight he was going to start,
when he began this thread?
For my money, if I had enough support height to support two 1/4 wave ground
planes, one above the other, I'd install a vertical 1/2 wave dipole and get
the current maximum higher above ground to
On 09/06/2013 09:26 AM, ZR wrote:
I would think that at 6-12' spacing from the tower it would minimize
interaction on 160 or 80?
I don't know, Carl. I'll leave it to the experts. What I do know is
I have made several attempts to erect a vertical for 80 meters near
my 160 meter tower, using
Carl and Charlie,
I am not sure it would even be close to practical or even doable, but I
remember seeing an old book on verticals written by a prior Navy Captain, I
believe. He had a very interesting design for what WE would, today, call a
collinear that was 3/4 wave length tall on 20
Mike,
This is the book.
http://store.cq-amateur-radio.com/Detail.bok?no=26
73, Tony K4QE
On Fri, Sep 6, 2013 at 10:41 PM, Mike Armstrong armst...@aol.com wrote:
Carl and Charlie,
I am not sure it would even be close to practical or even doable, but I
remember seeing an old book on
Hi, Mike
I remember the guy that you are referring to, but it's been so many years
that I don't remember his last name tither. He published a book via either
ARRL or CQ mag.
A collinear 1/2 wave over a 1/4 wave GP has certainly been done and used
commercially at VHF. The skirt can also be
Thanks, Tony
Yes, that's the one! I was pretty sure that it was published by CQ, but I
was having a senior moment and couldn't remember Paul's last name! J
73,
Charlie, K4OTV
From: Anthony Scandurra [mailto:anthony.scandu...@gmail.com]
Sent: Friday, September 06, 2013 10:52 PM
To:
Tony, Thanks...,. that is the one. As I recall a very good book from my
youth. It was one of the first antenna books that I remember reading in my
early ham years.. I think its original publishing date was after I was
first licensed (1960, when I was an ancient 8 years old... LOL). But
Hey.. IF the tower is tall enough for that duty (3/4 wave tall), then you
could put that skirt on the middle 1/4 wave, as it were, and you got
'er.. Could he be that lucky? I have to admit, other than right this
second, I hadn't ever considered that as a possibility. It should work so
I have the book. It is among the first antenna books I bought in 78 when I was
first starting in this hobby.
The book is The Amateur Radio Vertical Antenna Handbook by Capt. Paul H. Lee,
USN retired N6PL SK.
I built one of the 1/2 over 1/4 wave that you gentlemen are talking about for
20m
On 09/06/2013 09:26 AM, ZR wrote:
I would think that at 6-12' spacing from the tower it would minimize
interaction on 160 or 80?
I don't know, Carl. I'll leave it to the experts. What I do know is I have
made several attempts to erect a vertical for 80 meters near my 160 meter
tower, using
Say Paul I am going to try the same setup except ground the 80m vertical as a
close (5') coupled radiator and see what the feed impedance of the 160 vertical
is on 80. It models well...
On 09/06/2013 09:26 AM, ZR wrote:
I would think that at 6-12' spacing from the tower it would minimize
26 matches
Mail list logo
