Long inverted V not working well, why?
 

I just put up an inverted V that is up about 70 feet in the center and
about 15 feet at the ends. Each leg is about 130 feet long, or about 260
feet overall, which is right around a half wave for 160 meters. It is fed
with ladder line and an LDG auto-tuner.

I also have a dipole antenna that's up about 17 feet and is a half wave
for certain MARS / CAP frequencies above the 75 meter band, hence it's a
bit short for 75 meters. That antenna is coax fed and goes through a
different LDG auto-tuner which allows me to use it on 75/80 meters with a
good match.

The long and high inverted V doesn't work any better than the short and
low dipole, and in some cases doesn't work as well.

I have checked all the connections on the inverted V and even did a
continuity check from each side of the ladder line, up through the feed
point, out each leg to the end of each leg, and all seems OK.

I have tried switching auto-tuners (taking the one that's on the coax-fed
dipole and putting it on the inverted V) with no discernible difference.

Seems very strange. Any ideas that might account for why the V doesn't
work better?

Long inverted V not working well, why?
 

Rick (W-A-one-R-K-T) wrote:
Seems very strange. Any ideas that might account for why the V doesn't
work better?

The key is the combination of feedpoint impedance and
length of the ladder-line. Some lengths of ladder-line
at some frequencies are close to worst case. For instance,
if the feedpoint of the 160m dipole is 6000 ohms on 75m,
you certainly don't want to feed it with 1/2WL of
ladder-line on 75m.

The free demo version of EZNEC available from eznec.com
will probably tell you what is wrong with your installation.

There's a DOS program on my web page that will tell you
the optimum lengths for feedline. It can be downloaded
from http://www.w5dxp.com/imax.exe

For instance, with a 260 foot dipole used with 450 ohm
ladder-line on 3.8 MHz, the optimum feedline lengths
are ~55 feet and ~172 feet. If your feedline length is
halfway between those two lengths, i.e. ~113 feet, it
is a worst case impedance situation for 3.8 MHz.
--
73, Cecil http://www.w5dxp.com

Long inverted V not working well, why?
 

"Rick (W-A-one-R-K-T)" wrote in message
.. .

I just put up an inverted V that is up about 70 feet in the center and
about 15 feet at the ends. Each leg is about 130 feet long, or about 260
feet overall, which is right around a half wave for 160 meters. It is fed
with ladder line and an LDG auto-tuner.

I also have a dipole antenna that's up about 17 feet and is a half wave
for certain MARS / CAP frequencies above the 75 meter band, hence it's a
bit short for 75 meters. That antenna is coax fed and goes through a
different LDG auto-tuner which allows me to use it on 75/80 meters with a
good match.

The long and high inverted V doesn't work any better than the short and
low dipole, and in some cases doesn't work as well.

I have checked all the connections on the inverted V and even did a
continuity check from each side of the ladder line, up through the feed
point, out each leg to the end of each leg, and all seems OK.

I have tried switching auto-tuners (taking the one that's on the coax-fed
dipole and putting it on the inverted V) with no discernible difference.

Seems very strange. Any ideas that might account for why the V doesn't
work better?


It could depend on where the stations are you are trying to work. If they
are closer than about 200 to 300 miles on 75 meters then the lower antenna
probably will work beter. It is low to the ground and it tends to shoot the
signal up so it bounces down and covers the local area. The other antenna
will tend to send the signal out to more distance places. I have not done
the math for the angle of the higher antenna, but seems that it might too
steep. It should not be any less than about 120 deg where the wires come
together. It could also be the directions the stations are from you.

I have an off center fed antenna up about 50 feet that is about 130 feet
long and another dipole cut for 80 meters that is about 20 feet up. Most of
the locals are much stronger on the lower antenna.
I put it up because I like to talk to a couple of stations that are less
than 100 miles away.

Long inverted V not working well, why?
 

"Rick (W-A-one-R-K-T)" wrote in message
.. .

I just put up an inverted V that is up about 70 feet in the center and
about 15 feet at the ends. Each leg is about 130 feet long, or about 260
feet overall, which is right around a half wave for 160 meters. It is fed
with ladder line and an LDG auto-tuner.

I also have a dipole antenna that's up about 17 feet and is a half wave
for certain MARS / CAP frequencies above the 75 meter band, hence it's a
bit short for 75 meters. That antenna is coax fed and goes through a
different LDG auto-tuner which allows me to use it on 75/80 meters with a
good match.

The long and high inverted V doesn't work any better than the short and
low dipole, and in some cases doesn't work as well.

I have checked all the connections on the inverted V and even did a
continuity check from each side of the ladder line, up through the feed
point, out each leg to the end of each leg, and all seems OK.

I have tried switching auto-tuners (taking the one that's on the coax-fed
dipole and putting it on the inverted V) with no discernible difference.

Seems very strange. Any ideas that might account for why the V doesn't
work better?


you left out many details.
1. on what band did you do these tests?
2. what where your criteria for evaluating 'better'? swr, rx noise, rx
signal strength, tx field strength, tx signal measurements by someone at
some distance from you?
3. at what distance were the stations you compared, if that is what you did?
4. at what time of day/night, and on what date (important if there was some
kind of geomagnetic disturbance or some other propagation anomaly that day).
5. over how long of a period of time have you made these observations?
6. in what directions were the stations relative to each of the v's?
7. how close together are the v's?
8. what is supporting the v's?

Long inverted V not working well, why?
 

On Sat, 12 May 2007 08:02:52 -0400, "Rick (W-A-one-R-K-T)"
wrote:


I just put up an inverted V that is up about 70 feet in the center and
about 15 feet at the ends. Each leg is about 130 feet long, or about 260
feet overall, which is right around a half wave for 160 meters. It is fed
with ladder line and an LDG auto-tuner.

I also have a dipole antenna that's up about 17 feet and is a half wave
for certain MARS / CAP frequencies above the 75 meter band, hence it's a
bit short for 75 meters. That antenna is coax fed and goes through a
different LDG auto-tuner which allows me to use it on 75/80 meters with a
good match.

The long and high inverted V doesn't work any better than the short and
low dipole, and in some cases doesn't work as well.

I have checked all the connections on the inverted V and even did a
continuity check from each side of the ladder line, up through the feed
point, out each leg to the end of each leg, and all seems OK.

I have tried switching auto-tuners (taking the one that's on the coax-fed
dipole and putting it on the inverted V) with no discernible difference.

Seems very strange. Any ideas that might account for why the V doesn't
work better?


http://www.cebik.com/wire/vang.html

Long inverted V not working well, why?
 

On Sat, 12 May 2007 13:03:31 +0000, Dave wrote:

1. on what band did you do these tests?

Mostly 80 and 40, since those are the frequencies near where my two
reference dipoles are cut (the one I mentioned, cut a bit above 80 meters,
and a second 40-meter dipole at the same elevation, 17 feet, fed from the
same coax feedline).

2. what where your criteria for evaluating 'better'? swr, rx noise, rx
signal strength, tx field strength, tx signal measurements by someone at
some distance from you?

The only criterion I have available right now is received signal strength.
I don't yet have the resources to do transmit signal strength
measurements.

3. at what distance were the stations you compared,

Some were regional, less than 200 miles away, and so of course I would
have expected the low dipole to perform well, perhaps better than the
inverted vee. However, others were 500 to 1000 miles away, in places like
Virginia and Georgia (I'm in New Hampshire). Consistently, they came in
as well, or nearly so, and sometimes better, on the dipole than on the V.

4. at what time of day/night, and on what date

I work at home, and so I am able to get on the air several times during
each day. I ran some tests on the ECARS net at 7255 during the day,
generally from about 10 AM until about 3 PM EDT, and on 80 meter CW and 75
meter SSB during the early to mid evening. I did this every day for about
the last week and a half or so (for reference, today is Saturday, May 12).

5. over how long of a period of time have you made these observations?

As noted above, about the last week and a half or so.

6. in what directions were the stations relative to each of the v's?

There is only one V, and the other is a dual band dipole (75 and 40 meters
fed with one coax). The V and the 75-meter dipole are oriented roughly
east and west, and the 40-meter dipole is oriented roughly east-southeast
and west-northwest. Most of the stations I tested with were in Ohio down
through Florida, and so were about 260 degrees true down to about 210
degrees true ... especially in the case of the Ohio stations, not really
optimal for the antenna orientation, and yet an inverted vee should have
been much less sensitive to that than a dipole.

7. how close together are the v's?

The V and the dipole are approximately 30 feet apart horizontally and 50
feet apart vertically at their feedpoints, hence their feedpoints are a
bit under 60 feet apart.

8. what is supporting the v's?

The V is supported by a tall tree in the back yard. The tree doesn't have
many branches or much foliage, and what it does have are high up, mostly
higher than the feedpoint.

The dipole is supported by trees on each end.

Long inverted V not working well, why?
 

On Sat, 12 May 2007 06:42:30 -0700, Danny Richardson wrote:

http://www.cebik.com/wire/vang.html

Good morning, Danny.

Thanks for the pointer. That one was a real eye opener. I always thought
that any angle 90 degrees or greater at the feedpoint was OK. I think
mine is something like about 100 degrees. I'll see if I can raise the
ends up a bit and see what difference that makes.

Long inverted V not working well, why?
 

how far apart are the ends?

On May 12, 5:02 am, "Rick (W-A-one-R-K-T)"
wrote:
I just put up an inverted V that is up about 70 feet in the center and
about 15 feet at the ends. Each leg is about 130 feet long, or about 260
feet overall, which is right around a half wave for 160 meters. It is fed
with ladder line and an LDG auto-tuner.

I also have a dipole antenna that's up about 17 feet and is a half wave
for certain MARS / CAP frequencies above the 75 meter band, hence it's a
bit short for 75 meters. That antenna is coax fed and goes through a
different LDG auto-tuner which allows me to use it on 75/80 meters with a
good match.

The long and high inverted V doesn't work any better than the short and
low dipole, and in some cases doesn't work as well.

I have checked all the connections on the inverted V and even did a
continuity check from each side of the ladder line, up through the feed
point, out each leg to the end of each leg, and all seems OK.

I have tried switching auto-tuners (taking the one that's on the coax-fed
dipole and putting it on the inverted V) with no discernible difference.

Seems very strange. Any ideas that might account for why the V doesn't
work better?

Long inverted V not working well, why?
 

On Sat, 12 May 2007 10:37:13 -0400, Rick (W-A-one-R-K-T) wrote:

Thanks for the pointer. That one was a real eye opener. I always thought
that any angle 90 degrees or greater at the feedpoint was OK. I think
mine is something like about 100 degrees.

Actually I just calculated it out and it's more like around 130 degrees,
or each leg is just 25 degrees down from horizontal. So, according to
Cebik that should be pretty good.

Long inverted V not working well, why?
 

On Sat, 12 May 2007 09:27:47 -0700, herbert.don wrote:

how far apart are the ends?

Around 235 feet.

Long inverted V not working well, why?
 

Rick (W-A-one-R-K-T) wrote:
On Sat, 12 May 2007 10:37:13 -0400, Rick (W-A-one-R-K-T) wrote:
Thanks for the pointer. That one was a real eye opener. I always thought
that any angle 90 degrees or greater at the feedpoint was OK. I think
mine is something like about 100 degrees.

Actually I just calculated it out and it's more like around 130 degrees,
or each leg is just 25 degrees down from horizontal. So, according to
Cebik that should be pretty good.

What is the length of your feedline?
--
73, Cecil http://www.w5dxp.com

Long inverted V not working well, why?
 

On Sat, 12 May 2007 12:47:32 -0500, Cecil Moore wrote:

What is the length of your feedline?

That I don't know at the moment. I downloaded your imax.exe program and
ran some numbers.

There sure aren't very many numbers that are good for all bands 160
through 10.

No doubt my feedline is wrong for a lot of frequencies, made more clear by
the fact that there are a few frequencies where my LDG autotuner can't
find a match.

However, how much does the feedline length matter IF the autotuner is able
to find a good match point?

I can get 1.5:1 or better from everywhere in the 160 and 80 meter bands,
and the high end of the 40-meter band (on the low end I can't get below
about 2:1).

I'm about to go outside and try some different feedline lengths.

Long inverted V not working well, why?
 

Rick (W-A-one-R-K-T) wrote:
No doubt my feedline is wrong for a lot of frequencies, made more clear by
the fact that there are a few frequencies where my LDG autotuner can't
find a match.

However, how much does the feedline length matter IF the autotuner is able
to find a good match point?

Some impedances are outside the matching range and some
impedances are barely inside the matching range. Some
of the latter may not be a "good" match point. I model
my antenna systems to get a ballpark idea of what
impedance I am up against and use an antenna analyzer
to fine tune the system.
--
73, Cecil http://www.w5dxp.com

Long inverted V not working well, why?
 

Rick (W-A-one-R-K-T) wrote:
. . .
The only criterion I have available right now is received signal strength.
I don't yet have the resources to do transmit signal strength
measurements.
. . .

Do you expect them to be different? Why?

Roy Lewallen, W7EL

Long inverted V not working well, why?
 

On Sat, 12 May 2007 13:33:16 -0700, Roy Lewallen wrote:

Do you expect them to be different? Why?

Good evening Roy...

Well, yeah... sorta...

Wouldn't one normally expect a "better" antenna to be "better" on receive
(i.e. give a stronger received signal) as well as on transmit?

Long inverted V not working well, why?
 

"Rick (W-A-one-R-K-T)" wrote in message
.. .
On Sat, 12 May 2007 13:33:16 -0700, Roy Lewallen wrote:

Do you expect them to be different? Why?

Good evening Roy...

Well, yeah... sorta...

Wouldn't one normally expect a "better" antenna to be "better" on receive
(i.e. give a stronger received signal) as well as on transmit?


yes, a 'better' antenna would be... but higher and longer don't necessarily
mean 'better'.

Long inverted V not working well, why?
 

Then it should work fine
yes you do seem to have a problem. maybe if you shrtened it up some.

On May 12, 10:46 am, "Rick (W-A-one-R-K-T)"
wrote:
On Sat, 12 May 2007 09:27:47 -0700, herbert.don wrote:
how far apart are the ends?

Around 235 feet.

Long inverted V not working well, why?
 

You should definitely expect the difference between two antennas to be
the same in terms of signal strength for transmitting and receiving.
However, the antenna which produces the stronger signal isn't
necessarily the better receiving antenna. What counts when receiving is
signal/noise ratio, and the the antenna producing the strongest signal
may well produce a worse signal/noise ratio.

Doing transmit signal tests is entirely useless unless you happen across
someone with a step attenuator who knows how to use it, and the patience
to make many measurements as QSB fades you in and out. A friend of mine
gets perverse pleasure out of the dramatic differences other people
report between "antenna A" and "antenna B", when they're actually the
same antenna.

Roy Lewallen, W7EL

Rick (W-A-one-R-K-T) wrote:
On Sat, 12 May 2007 13:33:16 -0700, Roy Lewallen wrote:

Do you expect them to be different? Why?

Good evening Roy...

Well, yeah... sorta...

Wouldn't one normally expect a "better" antenna to be "better" on receive
(i.e. give a stronger received signal) as well as on transmit?

Tuning an antenna
 

I have been reading the Inverted Vee thread about the differences in
receive and s/n.

My process of using the tuner is to find the highest noise level,
then, turn on the carrier and fine tune to the lowest SWR. Often I
find that the signal strength isn't as good as it was before tuning.

Assuming the SWR is acceptable when tuned to the best signal, even
though it is not at its lowest, would it be better to leave the tuner
at the best received signal and use the radio with a bit higher SWR?

I am talking about SWR below 2:1, (not 10:1) as measured by the meter
or radio at time of tuning. For me, acceptable SWR for my solid state
rigs is 1.7:1 as 1.8:1 often causes protective circuits to kick in and
reduce power.

Comments?

Buck
N4PGW

--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."

Tuning an antenna
 

Buck wrote:
I have been reading the Inverted Vee thread about the differences in
receive and s/n.

My process of using the tuner is to find the highest noise level,
then, turn on the carrier and fine tune to the lowest SWR. Often I
find that the signal strength isn't as good as it was before tuning.

Assuming the SWR is acceptable when tuned to the best signal, even
though it is not at its lowest, would it be better to leave the tuner
at the best received signal and use the radio with a bit higher SWR?

I am talking about SWR below 2:1, (not 10:1) as measured by the meter
or radio at time of tuning. For me, acceptable SWR for my solid state
rigs is 1.7:1 as 1.8:1 often causes protective circuits to kick in and
reduce power.

Comments?

Buck
N4PGW

It would be really neat if we had a tuner that would selectively tune
the signal and noise. But alas, we don't. At HF, the signal and noise
are both coming from outside the antenna, so anything we do at the tuner
-- or anywhere between the antenna and receiver -- affects both equally.
The tuner won't affect the received s/n ratio unless you get it so badly
mistuned that you start hearing receiver noise, which isn't likely at
HF. So tune it any way you want.

For transmitting, you're always best off getting as much power to the
antenna as you can. (I mean actual power, not "forward power".) What
you're trying to do is make the best s/n ratio at the other guy's
receiver. You can't do anything about his noise, but for every dB you
increase your signal, you get a one dB improvement in the s/n ratio at
his end. This means having an SWR low enough that your rig doesn't shut
down. Unless you have an extraordinarily lossy transmission line, any
SWR below the shutdown point will get the same amount of power to the
antenna for practical purposes.

At VHF and above, receiver noise is usually greater than atmospheric
noise, so the rules change for receiving antennas. There, you do want to
get as much signal from your antenna as you can in order to get the best
s/n ratio. The rule for transmitting is still the same, though.

Roy Lewallen, W7EL

Tuning an antenna
 

On Sat, 12 May 2007 20:48:44 -0700, Roy Lewallen
wrote:


It would be really neat if we had a tuner that would selectively tune
the signal and noise. But alas, we don't. At HF, the signal and noise
are both coming from outside the antenna, so anything we do at the tuner
-- or anywhere between the antenna and receiver -- affects both equally.
The tuner won't affect the received s/n ratio unless you get it so badly
mistuned that you start hearing receiver noise, which isn't likely at
HF. So tune it any way you want.

For transmitting, you're always best off getting as much power to the
antenna as you can. (I mean actual power, not "forward power".) What
you're trying to do is make the best s/n ratio at the other guy's
receiver. You can't do anything about his noise, but for every dB you
increase your signal, you get a one dB improvement in the s/n ratio at
his end. This means having an SWR low enough that your rig doesn't shut
down. Unless you have an extraordinarily lossy transmission line, any
SWR below the shutdown point will get the same amount of power to the
antenna for practical purposes.

At VHF and above, receiver noise is usually greater than atmospheric
noise, so the rules change for receiving antennas. There, you do want to
get as much signal from your antenna as you can in order to get the best
s/n ratio. The rule for transmitting is still the same, though.

Roy Lewallen, W7EL

Thanks, Roy,

A friend of mine suggests I setup a field strength meter and tune for
maximum fs. I don't usually use baluns so I would wonder how accurate
that would be.

Currently, I am tuning my gutters up for HF. I checked it with an
analyzer the other day and found it is an excellent 160 meter and 20
meter antenna without the tuner (swr-wise). In the meantime I am
building a vertical for 20 and up.

Thanks again,
73 for now,
BUck
N4PGW

--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."

Long inverted V not working well, why?
 

"Rick (W-A-one-R-K-T)" wrote in message
.. .
On Sat, 12 May 2007 09:27:47 -0700, herbert.don wrote:

how far apart are the ends?

Around 235 feet.

Is there a reason you are using a 160 m antenna on 40/80 meters? A shorter
antenna would get the ends a lot higher, assuming you used the same end
supports.

Tam/WB2TT

Long inverted V not working well, why?
 

On Sun, 13 May 2007 09:26:13 -0400, Tam/WB2TT wrote:

Is there a reason you are using a 160 m antenna on 40/80 meters?

So I can get decent results on 160.

Long inverted V not working well, why?
 

"Rick (W-A-one-R-K-T)" wrote in message
.. .

I just put up an inverted V that is up about 70 feet in the center and
about 15 feet at the ends. Each leg is about 130 feet long, or about 260
feet overall, which is right around a half wave for 160 meters. It is fed
with ladder line and an LDG auto-tuner.

I also have a dipole antenna that's up about 17 feet and is a half wave
for certain MARS / CAP frequencies above the 75 meter band, hence it's a
bit short for 75 meters. That antenna is coax fed and goes through a
different LDG auto-tuner which allows me to use it on 75/80 meters with a
good match.

The long and high inverted V doesn't work any better than the short and
low dipole, and in some cases doesn't work as well.

I have checked all the connections on the inverted V and even did a
continuity check from each side of the ladder line, up through the feed
point, out each leg to the end of each leg, and all seems OK.

I have tried switching auto-tuners (taking the one that's on the coax-fed
dipole and putting it on the inverted V) with no discernible difference.

Seems very strange. Any ideas that might account for why the V doesn't
work better?


One of the bad things about stationary high gain antennas . It may have gain
out the wazoo but if its not putting the signal in the right place it doesnt
do much good.

Jimmie

Tuning an antenna
 

Buck wrote:

A friend of mine suggests I setup a field strength meter and tune for
maximum fs. I don't usually use baluns so I would wonder how accurate
that would be.
. . .

That's a perfectly good way to adjust a tuner, providing the meter is
far enough away from your transmitter that direct leakage radiation from
the transmitter and line between it and the tuner aren't making a
significant difference. As long as it is, it doesn't matter if you have
a balun or not, or whether your feedline is radiating or not. Adjusting
the tuner has no effect on how your system radiates, just how much. The
field strength meter is sampling just one part of the overall pattern.
But adjusting the tuner increases or decreases all parts of the pattern
in proportion, so the field strength meter tells you what you want to know.

A field strength meter isn't, however, usually a good way of judging
whether a change in the antenna (as opposed to a tuner adjustment) is
good or bad. This is because changing the antenna does affect the
pattern, and the field strength meter only tells you what's happening in
one direction -- and likely in the near field, to boot.

Roy Lewallen, W7EL

Tuning an antenna
 

Buck wrote in
:

Currently, I am tuning my gutters up for HF. I checked it with an
analyzer the other day and found it is an excellent 160 meter and 20
meter antenna without the tuner (swr-wise). In the meantime I am
building a vertical for 20 and up.

I don't know if there is a different meaning for the term gutters on your
side of the big pond, but if you mean the parts of a building for
collecting the rainwater from the roof...

Roy has talked to you briefly of the near field / induction fields. The
closer you place your antenna to noise sources (eg appliances, including
switched mode power supplies), the greater the response of your antenna
to those sources.

You have probably heard of the square law of light that tells you that
the power density of an EM wave decreases with the square of distance.
That is true in the radiation far field, but in the near field, the
induction fields decay more rapidly that that, and every bit of distance
you can put between your antenna and noise sources is worthwhile.

Wrapping your noise sources with your antenna sounds a sure fire way to
couple the very most interference... is that what you really want to do.

Owen

Tuning an antenna
 

On Sun, 13 May 2007 22:41:49 GMT, Owen Duffy wrote:

Buck wrote in
:

Currently, I am tuning my gutters up for HF. I checked it with an
analyzer the other day and found it is an excellent 160 meter and 20
meter antenna without the tuner (swr-wise). In the meantime I am
building a vertical for 20 and up.

I don't know if there is a different meaning for the term gutters on your
side of the big pond, but if you mean the parts of a building for
collecting the rainwater from the roof...


Yes, gutters are the rain collectors/diverters. I live in a duplex
apartment with gutters that go from just outside my back door, up the
wall two stories, across the roof edge for two apartments and down to
just above the ground on the far wall of the apartment.



Roy has talked to you briefly of the near field / induction fields. The
closer you place your antenna to noise sources (eg appliances, including
switched mode power supplies), the greater the response of your antenna
to those sources.

You have probably heard of the square law of light that tells you that
the power density of an EM wave decreases with the square of distance.
That is true in the radiation far field, but in the near field, the
induction fields decay more rapidly that that, and every bit of distance
you can put between your antenna and noise sources is worthwhile.

Wrapping your noise sources with your antenna sounds a sure fire way to
couple the very most interference... is that what you really want to do.

No, but until I build the vertical, it is all I have to work with.
This is a 'cliff-dweller' situation.


Owen

Thanks for the responses. I appreciate them.

Buck
N4PGW

--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."

Long inverted V not working well, why?
 

When an inverted V gets long with respect to wavelenth, the main lobe
elevates pretty dramatically, so you no longer get a decent take off
angle...lots of radiation at high angles, but very poor at the lower angles.

I found this precise problem when trying to run inverted vee's as extended
double zepps...they don't work very well compared to the same antenna as a
flat top.

All I had to do was model the V using EZNEC, and sure enough a 3D display of
the pattern showed the problem. The nice gain lobes I was looking for were
missing in the 2D display at the elevation angles I had expected. Going 3D
showed me where they went...way high, not very useful for what I wanted.

The moral of the story: if you want long (w/r to wavelength) dipoles to be
effective at low angles, only use flat top configuration. Inverted V's don't
do well as they get long with respect to wavelength.
"Rick (W-A-one-R-K-T)" wrote in message
.. .

I just put up an inverted V that is up about 70 feet in the center and
about 15 feet at the ends. Each leg is about 130 feet long, or about 260
feet overall, which is right around a half wave for 160 meters. It is fed
with ladder line and an LDG auto-tuner.

I also have a dipole antenna that's up about 17 feet and is a half wave
for certain MARS / CAP frequencies above the 75 meter band, hence it's a
bit short for 75 meters. That antenna is coax fed and goes through a
different LDG auto-tuner which allows me to use it on 75/80 meters with a
good match.

The long and high inverted V doesn't work any better than the short and
low dipole, and in some cases doesn't work as well.

I have checked all the connections on the inverted V and even did a
continuity check from each side of the ladder line, up through the feed
point, out each leg to the end of each leg, and all seems OK.

I have tried switching auto-tuners (taking the one that's on the coax-fed
dipole and putting it on the inverted V) with no discernible difference.

Seems very strange. Any ideas that might account for why the V doesn't
work better?