Vertical Dipole vs. Inverted V? (need help)
ner...@my-dejanews.com
I floated over here to ask this question because the good home brew antenna
makers are the amateur radio guys.
I am getting ready to install a modest CB (11m) base radio at my house. I
have a need for a low profile antenna that isn't too serious of a compromise.
The 5/8 and 1/2 wave vertical antennas are too tall and the long radials of
the 1/4 wave ground plane won't do either ( covenants and a wife). If I can
keep it unobtrusive I might be OK. I have narrowed it down to a 1/2 wave,
center fed, inverted V dipole or a 1/2 wave vertical dipole.
The inverted V would be mounted at one end of my house, at the peak (approx
25 feet high), with the legs angling down with the slope of the roof. The
main benefits seem to be very low profile and very inexpensive. The V
configuration should bring the antenna impedence down to 50 ohms or so. A
great match for the coax. The down side would be that, since it is mounted on
the side of the house, the legs would not be "in the clear". This is supposed
to be an omni-directional design, with the nulls pointed down. I am not clear
whether this wastes alot of energy transmitting up? I'm guessing there is a
bit of gain towards the slope of the legs, is this true? That would be OK
since it would give me a pattern that favors north-south communucations. That
is of some benefit where I live.
The vertical dipole would be constructed of two common 1/4 wave fiberglass
whips, mounted end to end and oriented vertically. The center feed point of
this antenna would mount on the end of the house at the peak, with the
vertical element extending above the roof and the lower leg extending down
the side of the house. The benefits would seem to be true omni directional
pattern with the nulls straight up and down. This seems like it would have a
very low angle of radiation for good distance. The down side seems to be
higher cost (slightly), less stealth with the vertical element (tolerable
however) and some mismatch between the antenna (70-80 ohms?) and the coax.
The lower element would also be very close to the side of the house.
Can you tell me if my logic is good here?
I am especialy curious about the radiation pattern and gain of these two
options. I realize my mounting location is less than ideal.
Is there any clear winner for local communications?
You assistance and expertise is appreciated .
nero.
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
William Lee
by all means put up the inverted Vee and compair the two. Then come back and
tell us all what the results are. CB AM and SSB is a lot like Amateur QRP
(low power operation) in that you need every advantage you can get to
maximize your 5 watt signal.
William Lee N5WRX
Marty Duplissey
vertical. The inverted V would show some loss in local contacts which I'm
sure you want since it's illigal to make long distance contacts on 11M :-)
Jesse Touhey wrote in message <37042ddf...@news.olypen.com>...
>>http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
>
>
>Nero, how about two 1/4wl fiberglass whips in a V
>, fed at the apex, apex mounted at the top of the
>eves, and the tips going up at 45 degrees? In
>other words, an upright V mounted up high.
>An inverted V with the legs close to the eves,
>operated on 27mhz will have quite a bit of loss.
>
>73, Jesse, W7OKI
CW
says...
an Antron 99. When switching betweenn the two, receivingg stations
usually could not tell the difference. Try the inverted l. Very easy to
hide and they work rather well. Mine was 25 feet vertical and 60 feet
horizontal.
--
CW
KC7NOD
ner...@my-dejanews.com
post, an antenna that tall is not going to fly with the neighbors or the
wife. You're talking 18 feet above the roof with a large diameter element vs.
8 ft above the roof with a thin diameter whip. I have already accepted the
compromise of less than a full size vertical. I am now trying to minimize the
weanesses of my remaining options.This was the reason for my post. I have
re-posted my original question below and would appreciate some input on the
merits of these two antennas. Thank you. nero
**************** REPOST************************************
Hi folks,
*********end of repost*******************
In article <7e0rjv$cjs$1...@camel15.mindspring.com>,
"William Lee" <wil...@interconnect.net> wrote:
> I think you would do better by seting up an antenna like the Antron 99. But
> by all means put up the inverted Vee and compair the two. Then come back and
> tell us all what the results are. CB AM and SSB is a lot like Amateur QRP
> (low power operation) in that you need every advantage you can get to
> maximize your 5 watt signal.
> William Lee N5WRX
>
-----------== Posted via Deja News, The Discussion Network ==----------
Jesse Touhey
ner...@my-dejanews.com wrote:
>The lower element would also be very close to the side of the house.
>
>Can you tell me if my logic is good here?
>
> I am especialy curious about the radiation pattern and gain of these two
>options. I realize my mounting location is less than ideal.
>
>Is there any clear winner for local communications?
>
>You assistance and expertise is appreciated .
>
>nero.
>
>
>-----------== Posted via Deja News, The Discussion Network ==----------
>http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
ner...@my-dejanews.com
>
> Nero, how about two 1/4wl fiberglass whips in a V
> , fed at the apex, apex mounted at the top of the
> eves, and the tips going up at 45 degrees? In
> other words, an upright V mounted up high.
> An inverted V with the legs close to the eves,
> operated on 27mhz will have quite a bit of loss.
>
> 73, Jesse, W7OKI
>
Jesse, I have never heard of nor considered an upright V. But, why the heck
not. Something new to stick in the antenna arsenal. I enjoy experimenting.
My inverted V was originally going to be made with 1/4 whips, but I figured
why spend the extra cash when I didn't need the support of a whip. Wire for
dipoles is so cheap. Another gent e-mailed me and noted the horizontal
polarization of the inverted V ( I imagine the upright V would be the same).
The overwhelming majority of CB rigs are mobiles with vertical antennas. This
difference would seem to give the nod to the vertical dipole.
Thanks for your input. nero
ner...@my-dejanews.com
I missed that one good. I just received another e-mail pointing this out. I
was too busy thinking about the theoretical increased gain a horizontal
dipole has over a vertical dipole. Not intersted in skip. This arrangement
doesn't lend itself well to consistant long distance communications anyway.
Thanks for your help, nero.
In article <erWM2.45$O94....@news12.ispnews.com>,
"Marty Duplissey" <mdupl...@lsbs.com> wrote:
> I would recommend going with the vertical.99% of the activity on 11M is
> vertical. The inverted V would show some loss in local contacts which I'm
> sure you want since it's illigal to make long distance contacts on 11M :-)
>
> Jesse Touhey wrote in message <37042ddf...@news.olypen.com>...
> >>-----------== Posted via Deja News, The Discussion Network ==----------
> >>http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
> >
> >
> >Nero, how about two 1/4wl fiberglass whips in a V
> >, fed at the apex, apex mounted at the top of the
> >eves, and the tips going up at 45 degrees? In
> >other words, an upright V mounted up high.
> >An inverted V with the legs close to the eves,
> >operated on 27mhz will have quite a bit of loss.
> >
> >73, Jesse, W7OKI
>
>
-----------== Posted via Deja News, The Discussion Network ==----------
Arnie Macy
look. http://people.delphi.com/cecilmoore/dipvsver.htm .
Arnie -
KT4ST
ner...@my-dejanews.com wrote in message <7e0qf1$v37$1...@nnrp1.dejanews.com>...
ner...@my-dejanews.com
cma...@sprynet.com (CW) wrote:
> In article <7e0qf1$v37$1...@nnrp1.dejanews.com>, ner...@my-dejanews.com
> says...
> > nero.
> At one time I had two antennas for 11 meters. An end fed inverted l and
> an Antron 99. When switching betweenn the two, receivingg stations
> usually could not tell the difference. Try the inverted l. Very easy to
> hide and they work rather well. Mine was 25 feet vertical and 60 feet
> horizontal.
> --
> CW
> KC7NOD
>
CW, I hadn't even considered an inverted L. Sounds interesting.
Thanks to everyone that responded by e-mail or posting. Time for the fun to
begin. nero
Mark Keith
> I am especialy curious about the radiation pattern and gain of these two
> options. I realize my mounting location is less than ideal.
The vertical should be the most omni of the two.
>
> Is there any clear winner for local communications?
>
> You assistance and expertise is appreciated .
Neither is going to be a world beater. I'd probably go with the vertical
being as both will be below the roof line. The problem with the 1/2
vertical you want to make is the feeding. You will have feed problems
trying to feed a vertical from the side. You would be better off making
a base fed 1/2 vertical. And run that at a level you can get away with.
Remember on a 1/2 wave , the maximum currents are in the middle of the
element.
You might want to try both, but I would think overall they will be about
the same on long haul. For local the vertical should be better. If you
have to side feed, make sure your coax extends a ways out from the
antenna before dropping to the shack. I'm using a base fed 1/2 vertical
here right now at 20 ft on 10m. Works pretty good for a simple antenna.
You can base feed with a single turn loop . MK
--
http://web.wt.net/~nm5k
William Lee
inside of it.
How can they complain about you flying the American flag.
William Lee
ner...@my-dejanews.com wrote in message <7e15tf$93h$1...@nnrp1.dejanews.com>...
>William, I would love to put up the A-99, but as I described in my
original
>post, an antenna that tall is not going to fly with the neighbors or the
>wife. You're talking 18 feet above the roof with a large diameter element
vs.
>8 ft above the roof with a thin diameter whip. I have already accepted the
>compromise of less than a full size vertical. I am now trying to minimize
the
>weanesses of my remaining options.This was the reason for my post. I have
>re-posted my original question below and would appreciate some input on the
>merits of these two antennas. Thank you. nero
>
>**************** REPOST************************************
> I am especialy curious about the radiation pattern and gain of these two
>options. I realize my mounting location is less than ideal.
>
>Is there any clear winner for local communications?
>
>You assistance and expertise is appreciated . nero.
>
>*********end of repost*******************
>
>In article <7e0rjv$cjs$1...@camel15.mindspring.com>,
> "William Lee" <wil...@interconnect.net> wrote:
>> I think you would do better by seting up an antenna like the Antron 99.
But
>> by all means put up the inverted Vee and compair the two. Then come back
and
>> tell us all what the results are. CB AM and SSB is a lot like Amateur QRP
>> (low power operation) in that you need every advantage you can get to
>> maximize your 5 watt signal.
>> William Lee N5WRX
>>
>
ner...@my-dejanews.com
nm...@wt.net wrote:
> >
> > I am especialy curious about the radiation pattern and gain of these two
> > options. I realize my mounting location is less than ideal.
> The vertical should be the most omni of the two.
> >
> >
> > You assistance and expertise is appreciated .
>
> being as both will be below the roof line. The problem with the 1/2
> vertical you want to make is the feeding. You will have feed problems
> trying to feed a vertical from the side. You would be better off making
> a base fed 1/2 vertical. And run that at a level you can get away with.
> Remember on a 1/2 wave , the maximum currents are in the middle of the
> element.
I passed on this option because I thought it would be difficult to properly
match an end fed 1/2 vertical. I know the commercial versions have components
at the base to handle this.
> You might want to try both, but I would think overall they will be about
> the same on long haul. For local the vertical should be better. If you
> have to side feed, make sure your coax extends a ways out from the
> antenna before dropping to the shack.
If I go this route the coax will extend horizontally away from the antenna
for 40 feet along the roof of the attic before it heads down to the radio.
This should be plenty.
> I'm using a base fed 1/2 vertical
> here right now at 20 ft on 10m. Works pretty good for a simple antenna.
> You can base feed with a single turn loop . MK
Could you give me more specific details as to what you mean by a single turn
loop? Is this similar to running a single piece of heavy gauge copper once
around the base of the antenna, with a sliding connection from coax to
antenna for tuning?
> --
> http://web.wt.net/~nm5k
>
Thanks, nero.
ner...@my-dejanews.com
Mark Keith
>
> I passed on this option because I thought it would be difficult to properly
> match an end fed 1/2 vertical. I know the commercial versions have components
> at the base to handle this.
attached from ground at one end to the base of the radiator at the
other. You run a tap from coax hot to a point on the loop where you get
the best SWR. Also for best match use a cap from loop ground to the
radiator. But surprisingly I found lately this is not absolutely
neccesary as I just made one a few weeks ago from a cb antenna and I
used the loop that was included. At first I tried with no cap expecting
a high SWR and having to add the cap, but it turned out to be a good
match with just a loop. I was pretty surprised as I had always used a
cap in previous versions. On a 10m version the loop is about 11 inches
diameter and if a cap is used, about 50 pf. I make these from a piece of
coax. If you look at a cushcraft AR-10 vertical this is almost exactly
the same. In fact you could buy one of these fairly cheap if you didn't
want to make one. But , I wouldn't be afraid to make it, they are easy
to tune. I've run quite a few. You only need a 16 ft vertical section.
MK
>
>
--
http://web.wt.net/~nm5k
ner...@my-dejanews.com
tracy glenn
> The vertical dipole would be constructed of two common 1/4 wave fiberglass
> whips, mounted end to end and oriented vertically. The center feed point of
helical wound whips and not the thin wire coatred with fiberglass,either
way I highly recommend the same setup but use 2 102" stainless steel
whips and don't forget to add a 1/4 turn quick disconnect,or spring,or
something to make up the extra length.if your lucky you can find whips
the right length without the spring.
If you play with the spacing and use a hairpin match you can easily
see 50 ohms.AB7RS
ner...@my-dejanews.com
nero
In article <7e4alj$sso$1...@nnrp1.dejanews.com>,
nm...@wt.net wrote:
> In article <370507...@wt.net>,
> nm...@wt.net wrote:
> > >
> > > I am especialy curious about the radiation pattern and gain of these two
> > > options. I realize my mounting location is less than ideal.
> > The gain appx the same. The pattern? who knows? Try elnec demo for that.
> > The vertical should be the most omni of the two.
> > >
> > > Is there any clear winner for local communications?
> > The vertical.
> > >
> > > You assistance and expertise is appreciated .
> >
> > Neither is going to be a world beater. I'd probably go with the vertical
> > being as both will be below the roof line. The problem with the 1/2
> > vertical you want to make is the feeding. You will have feed problems
> > trying to feed a vertical from the side. You would be better off making
> > a base fed 1/2 vertical. And run that at a level you can get away with.
> > Remember on a 1/2 wave , the maximum currents are in the middle of the
> > element.
>
> I passed on this option because I thought it would be difficult to properly
> match an end fed 1/2 vertical. I know the commercial versions have components
> at the base to handle this.
>
> > You might want to try both, but I would think overall they will be about
> > the same on long haul. For local the vertical should be better. If you
> > have to side feed, make sure your coax extends a ways out from the
> > antenna before dropping to the shack.
>
> If I go this route the coax will extend horizontally away from the antenna
> for 40 feet along the roof of the attic before it heads down to the radio.
> This should be plenty.
>
> > I'm using a base fed 1/2 vertical
> > here right now at 20 ft on 10m. Works pretty good for a simple antenna.
> > You can base feed with a single turn loop . MK
>
> Could you give me more specific details as to what you mean by a single turn
> loop? Is this similar to running a single piece of heavy gauge copper once
> around the base of the antenna, with a sliding connection from coax to
> antenna for tuning?
>
> > --
> > http://web.wt.net/~nm5k
> >
>
> Thanks, nero.
>