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What antenna should I build?

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JT Croteau-2

What antenna should I build?

My only antenna currently here at the home QTH is an HF2V vertical
which does great for long haul DX on 40 and 80 but in general is not
good for local or regional work. I just launched some monofilament
over the only high branch in my yard at 50'.

As I only have a single support, I'm looking at some suggestions on
constructing a multiband vee wire antenna but have limited materials
on hand and even more limited $$ to go out an buy stuff at the moment.

Here is what I have in the junk box:

75' of RG213
~30' of solid conductor commercial ladder line
~800' of 14ga stranded insulated THN wire
Assortment of dog-bone style insulators
Wide assortment of PVC and nuts/bolts

What can I do with the above and the internal tuner in my K1 without
going out and buying anything? Ideally, I'd like something that will
load well on 80/40/30/20/15 but will settle for 40-15.

Anyone have any ideas?

Thanks

--
JT Croteau - W6FO - Canton, GA | K1 #292
ARS #2,147 | NoGA-QRP | SEDXC | ARRL
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Don Wilhelm-3

RE: What antenna should I build?

I would suggest a fanned dipole configuration with elements cut for 80, 40
and 20 meters - feed it with the RG-213 directly (or through a balun if you
have one).

Cut the elements for 40 and 20 plenty long (about 15%) and cut the 80 meter
elements for the low part of the band (3.5 MHz). You will have to do a lot
of cut and try to get it tuned - fan the elements for each band as far away
from each other as possible to reduce interaction (maybe easiest to guy them
in a circle 60 degrees apart around your center support), then start tuning
on the lowest band and work upward.

The theory is that the 80 meter wire will also serve on the 3rd harmonic at
30 meters and the 40 meter element will similarly serve on 15 as a 3/2
wavelength antenna, giving you coverage of 80 thru 15 meters with the 3
elements. The harmonic operation will only provide a low SWR if you cut the
80 and 40 meter sections for the low end of the band. The SWR may not be
perfect on all bands, but then you have a tuner to compensate, so it will be
tolerable with the RG-213.

Try it and see - it would give you a good multiband antenna even without a
tuner in many cases.

73,
Don W3FPR

> -----Original Message-----
>
> My only antenna currently here at the home QTH is an HF2V vertical
> which does great for long haul DX on 40 and 80 but in general is not
> good for local or regional work. I just launched some monofilament
> over the only high branch in my yard at 50'.
>
> As I only have a single support, I'm looking at some suggestions on
> constructing a multiband vee wire antenna but have limited materials
> on hand and even more limited $$ to go out an buy stuff at the moment.
>
> Here is what I have in the junk box:
>
> 75' of RG213
> ~30' of solid conductor commercial ladder line
> ~800' of 14ga stranded insulated THN wire
> Assortment of dog-bone style insulators
> Wide assortment of PVC and nuts/bolts
>
> What can I do with the above and the internal tuner in my K1 without
> going out and buying anything? Ideally, I'd like something that will
> load well on 80/40/30/20/15 but will settle for 40-15.
>
> Anyone have any ideas?
>
> Thanks
>
> --
> JT Croteau - W6FO - Canton, GA | K1 #292
> ARS #2,147 | NoGA-QRP | SEDXC | ARRL
>

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Ron D'Eau Claire-2

RE: What antenna should I build?

In reply to this post by JT Croteau-2

-----Original Message-----
My only antenna currently here at the home QTH is an HF2V vertical which
does great for long haul DX on 40 and 80 but in general is not good for
local or regional work. I just launched some monofilament over the only
high branch in my yard at 50'.

As I only have a single support, I'm looking at some suggestions on
constructing a multiband vee wire antenna but have limited materials on hand
and even more limited $$ to go out an buy stuff at the moment.

Here is what I have in the junk box:

75' of RG213
~30' of solid conductor commercial ladder line
~800' of 14ga stranded insulated THN wire
Assortment of dog-bone style insulators
Wide assortment of PVC and nuts/bolts

What can I do with the above and the internal tuner in my K1 without going
out and buying anything? Ideally, I'd like something that will load well on
80/40/30/20/15 but will settle for 40-15.

Anyone have any ideas?

----------------------------------

If you can arrange the wire to come close to your operating position
(window, etc.) forget the feed line and use an end-fed wire. Eliminating the
feed line eliminates the problem with feeder losses in a multiband antenna.

An end-fed inverted V works just as well as a center fed one. Make it as
long as possible to keep the feedpoint impedance high. The problem with most
end-fed wires is that they are only 1/4 wave long or even shorter. Such
antennas are highly-dependent upon a very good ground for good operation.
We're talking physical length, no electrical length. Short antennas that
have loading devices that make them "look" like they're a half wave long to
the RF are still inefficient.

You'll want a ground anyway to keep the rig at a low RF potential, even
though it's probably not needed for an efficient antenna on most bands. The
ideal length for a true ground-independent end fed antenna is a wire a half
wave long, but that's a problem with ATU's. They can't handle the very high
impedance the antenna will present. So the "trick" is to use as long a wire
as you can, greater than 1/2 wave is FB, that will still present an
impedance within the range of your ATU on all bands. If you want to work 80,
that'll mean something close to or greater than 130 feet. Now add insulated
counterpoise wires for each band. They can be run anywhere - along
baseboards, stapled to the side of the house, etc., as long as they are
insulated from ground and 1/4 wave long for each band. Keep the ends of the
counterpoises separate too, at least the last several feed of each wire.
Fewer counterpoises will often work, especially on the bands were the
antenna is close to 1/2 wave long or greater, but don't fall into the trap
of believing that a 1:1 SWR reported by the ATU means the antenna is working
efficiently. It only means the rig is feeding power efficiently. What the
antenna is doing is something quite different. You want to provide as good
an RF ground as you can for each band to ensure the radiator is getting
maximum RF current, especially on the lower-frequency bands were the antenna
is less than 1/2 wave long.

Fifty feet in height will provide excellent signals for close in operations
using an end-fed "inverted V" or sloping wire configuration on all the bands
below 30 meters and excellent low angle radiation for DX on the higher
bands. Even 40 will provide good DX at that height. The ideal height for a
horizontal antenna is about 1/2 wavelength above the ground. At 50 feet,
expect your horizontal wire to show 4 to 6 dB *GAIN* over your vertical,
thanks to the help horizontals get from ground reflections that verticals
don't. So it'll have the effect of doubling or quadrupling your effective
radiated power.

Start with all the wire that fits your yard and counterpoises cut for each
band. If your ATU can't find a match on some bands, start shortening the
antenna by small steps. Keep in mind that if the higher bands produce a
matching problem, you don't need to shorten it by much. For example,
shortening the antenna by 10 feet will have a huge effect on 15 meters and
virtually no effect on 40 or 80 meters. You can simply fold back the
radiator wire on itself and add guy line as needed to shorten it until you
find a length that will load on all bands. Folded back wire acts like a
"fat" wire to the RF, which flows over the outside of the wire, not through
the copper. Once you have a length that works on all bands, you can trim it
short and clean up the installation.

That would be my first choice. A second choice would be to center feed the
wire using the ladder line. You may or may not use a balun, especially if
the feed line can be brought to the rig "in the clear" where radiation from
the line won't be unduly absorbed by surrounding objects. Just hook one side
of the feeder to the hot conductor on the antenna jack and the other to the
case. The antenna acts like a combination radiator and counterpoise all
built into one.

My last choice would be to use the coax. If you do that you *must* have a
fairly low SWR on the coax to avoid excessive losses. I'm talking about the
coax SWR, not the SWR reported by the ATU. The SWR reported by the ATU is
the SWR between the tuner and the K1, not the SWR on the feeder. The easiest
way to have a acceptably-low SWR on the coax using a wire antenna is to
build parallel center fed dipoles (1/2 wave wires) for each band. Connect
each dipole in parallel with the others to the feeder with the feed point as
high as possible. Separate the far ends of the dipoles as much as possible
to avoid interaction. IF you put up a 40 meter dipole, you don't need
another one for 15 since a 40 meter dipole is 3/2 waves at 15 meters and
will produce a reasonably low SWR to the feedline on both bands. The other
bands will need their own separate wires, however.

Ron AC7AC

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sjolin

Re: [QRP-L] What antenna should I build?

In reply to this post by JT Croteau-2

Your HF2-V will work fine as is on 15 meters. I usually mine rather than my
Cushcraft R5 which also covers 15. The ground mounted Butternut does better
for dx while the R5 maybe better for the US and South America.

By the way you can load your HF2v up on 20 and 17 meters with your tuners if
you are using qrp. I wouldnt run high power or you might blow a capacitor.
If you add the 30 meter add on kit to the HF2V you use that band as well. By
the way you can also use the HF2v to work six meter e-skip.

73 de Dave, N0IT

----- Original Message -----
From: "JT Croteau" <[hidden email]>
To: "QRP-L" <[hidden email]>; "Elecraft" <[hidden email]>;
<[hidden email]>
Sent: Monday, June 12, 2006 1:25 PM
Subject: [QRP-L] What antenna should I build?

> My only antenna currently here at the home QTH is an HF2V vertical
> which does great for long haul DX on 40 and 80 but in general is not
> good for local or regional work. I just launched some monofilament
> over the only high branch in my yard at 50'.
>
> As I only have a single support, I'm looking at some suggestions on
> constructing a multiband vee wire antenna but have limited materials
> on hand and even more limited $$ to go out an buy stuff at the moment.
>
> Here is what I have in the junk box:
>
> 75' of RG213
> ~30' of solid conductor commercial ladder line
> ~800' of 14ga stranded insulated THN wire
> Assortment of dog-bone style insulators
> Wide assortment of PVC and nuts/bolts
>
> What can I do with the above and the internal tuner in my K1 without
> going out and buying anything? Ideally, I'd like something that will
> load well on 80/40/30/20/15 but will settle for 40-15.
>
> Anyone have any ideas?
>
> Thanks
>
> --
> JT Croteau - W6FO - Canton, GA | K1 #292
> ARS #2,147 | NoGA-QRP | SEDXC | ARRL
> ______________________________________________________________
> QRP-L mailing list
> Home: http://mailman.qth.net/mailman/listinfo/qrp-l
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>

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Ron D'Eau Claire-2

RE: What antenna should I build?

In reply to this post by Don Wilhelm-3

Don W3FPR wrote:

The theory is that the 80 meter wire will also serve on the 3rd harmonic at
30 meters and the 40 meter element will similarly serve on 15 as a 3/2
wavelength antenna, giving you coverage of 80 thru 15 meters with the 3
elements.

-----------------

Ha, Ha! Good point, Don. Shows how long it's been since I used a fan dipole:
since before 30 meters. Yes, a dipole for 80 is about 134 feet long and 3/2
waves on 30 meters is just about 141 feet, allowing for nominal end-effect.
That's close enough to use one wire on both bands.

Ron AC7AC

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Stuart Rohre

Re: What antenna should I build?

In reply to this post by JT Croteau-2

Take a look at the Ten Tec Vee beam, then remember that a non terminated Vee
beam is bi directional, so you do not need the termination resistors. Make
it up as a one support sloping vee as long as will fit your lot with the
angles suggested, 45 degrees. You can stake out the lower ends with tent
stakes and then move the direction by moving the stakes to steer the beam
for time of day and conditions. Feed it with the ladder line and to a tuner
for all band use.

Stuart
K5KVH

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Clyde Moody

[QRP-L] Re: [NoGaQRP] What antenna should I build?

In reply to this post by JT Croteau-2

I have read articles on the web recently that mention the low NVIS type
antenna's.
I'm not sure if your familiar with the concept but here is a link that I've
used
http://www.hamuniverse.com/nvisbeam.html

I kind of like the one they mention - the cloud warmer - it looks like a
neat concept.
I would think that if you are wanting to intentionally get a higher angle of
radiation for more regional / local stuff - (instead of that very low one
your vertical is producing) - this would be a pretty good candidate.
One thing that worried me however was ground losses (running QRP it matters)
with it being as low as it is. I think the reason this design above using
the director "element" beneath the main radiator is to minimize the ground
loss but I'm not sure. Just an idea..
Of course your monofiliment over the 50 ' limb wont come in handy on this
one... !

----- Original Message -----
From: "JT Croteau" <[hidden email]>
To: "QRP-L" <[hidden email]>; "Elecraft" <[hidden email]>;
<[hidden email]>
Sent: Monday, June 12, 2006 2:25 PM
Subject: [NoGaQRP] What antenna should I build?

> My only antenna currently here at the home QTH is an HF2V vertical
> which does great for long haul DX on 40 and 80 but in general is not
> good for local or regional work. I just launched some monofilament
> over the only high branch in my yard at 50'.
>
> As I only have a single support, I'm looking at some suggestions on
> constructing a multiband vee wire antenna but have limited materials
> on hand and even more limited $$ to go out an buy stuff at the moment.
>
> Here is what I have in the junk box:
>
> 75' of RG213
> ~30' of solid conductor commercial ladder line
> ~800' of 14ga stranded insulated THN wire
> Assortment of dog-bone style insulators
> Wide assortment of PVC and nuts/bolts
>
> What can I do with the above and the internal tuner in my K1 without
> going out and buying anything? Ideally, I'd like something that will
> load well on 80/40/30/20/15 but will settle for 40-15.
>
> Anyone have any ideas?
>
> Thanks
>
> --
> JT Croteau - W6FO - Canton, GA | K1 #292
> ARS #2,147 | NoGA-QRP | SEDXC | ARRL
> _______________________________________________
> NoGaQRP mailing list
> [hidden email]
> http://mailman.qth.net/mailman/listinfo/nogaqrp
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.394 / Virus Database: 268.8.3/361 - Release Date: 6/11/2006
>
>

James T. "Jim" Rogers, W4ATK-2

RE: What antenna should I build?

In reply to this post by JT Croteau-2

Gee,
I live in a restricted neighborhood and I could not be happier with my 40M
off center fed dipole I have stapled to the "ridgepole" in my garden home. I
mounted a 4:1 balun at the feed point and fed it with 1/2 wavelength of
coax. It works 80 thru 10 meters and is easily tuned with my KAT100 to 1:1
on 40 thru 10 and 1.2:1 on 80M.
Moving from band to band changes the radiation pattern and on 20M, it has a
pipeline into Europe and the Middle East. Made some nice contacts on the K2
alone, I very seldom QRO up to the big gun, the KPA100.

73s Jim, W4ATK

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n6wg

Re: What antenna should I build?

In reply to this post by JT Croteau-2

Hi JT
You mentioned the tree with a 50 ft support point.
What do you have to support the ends of your wires?
Also, what kind of real estate do you have to spread out
over? That would help us a lot in suggesting something.
Good luck and 73
Bob N6WG
----- Original Message -----
From: "JT Croteau" <[hidden email]>
To: "QRP-L" <[hidden email]>; "Elecraft" <[hidden email]>;
<[hidden email]>
Sent: Monday, June 12, 2006 11:25 AM
Subject: [Elecraft] What antenna should I build?

> My only antenna currently here at the home QTH is an HF2V vertical
> which does great for long haul DX on 40 and 80 but in general is not
> good for local or regional work. I just launched some monofilament
> over the only high branch in my yard at 50'.
>
> As I only have a single support, I'm looking at some suggestions on
> constructing a multiband vee wire antenna but have limited materials
> on hand and even more limited $$ to go out an buy stuff at the moment.
>
> Here is what I have in the junk box:
>
> 75' of RG213
> ~30' of solid conductor commercial ladder line
> ~800' of 14ga stranded insulated THN wire
> Assortment of dog-bone style insulators
> Wide assortment of PVC and nuts/bolts
>
> What can I do with the above and the internal tuner in my K1 without
> going out and buying anything? Ideally, I'd like something that will
> load well on 80/40/30/20/15 but will settle for 40-15.
>
> Anyone have any ideas?
>
> Thanks
>
> --
> JT Croteau - W6FO - Canton, GA | K1 #292
> ARS #2,147 | NoGA-QRP | SEDXC | ARRL
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

Mark Bayern-2

Re: What antenna should I build?

In reply to this post by James T. "Jim" Rogers, W4ATK-2

Jim,

That OCF sounds interesting, and I'm also in a restricted
neighborhood, but what is a '1/2 wavelength of coax' for an antenna
that covers 80 thru 10 meters?

Mark AD5SS

On 6/12/06, James T. Jim Rogers, W4ATK <[hidden email]> wrote:

> Gee,
> I live in a restricted neighborhood and I could not be happier with my 40M
> off center fed dipole I have stapled to the "ridgepole" in my garden home. I
> mounted a 4:1 balun at the feed point and fed it with 1/2 wavelength of
> coax. It works 80 thru 10 meters and is easily tuned with my KAT100 to 1:1
> on 40 thru 10 and 1.2:1 on 80M.
> Moving from band to band changes the radiation pattern and on 20M, it has a
> pipeline into Europe and the Middle East. Made some nice contacts on the K2
> alone, I very seldom QRO up to the big gun, the KPA100.
>
> 73s Jim, W4ATK
>

Craig Smith

RE: What antenna should I build?

In reply to this post by Ron D'Eau Claire-2

If you just had another few feet of ladder line to reach from your shack to
your feedpoint, Ron, my answer would be easy. The classic 88 ft center fed
doublet which your tuner would load fine on 80 thru 10. With the center at
50 ft, it would give you good coverage over the US on the low bands. But
guess you will need to cut some spacers from your PVC collection and make
some additional ladder line from your AWG 14 wire. Will take some time but
work just as well.

Have fun!
... Craig AC0DS

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Buck-4

RE: [QRP-L] What antenna should I build?

In reply to this post by JT Croteau-2

> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]]
> On Behalf Of JT Croteau
>
> Here is what I have in the junk box:
>
> 75' of RG213
> ~30' of solid conductor commercial ladder line
> ~800' of 14ga stranded insulated THN wire
> Assortment of dog-bone style insulators
> Wide assortment of PVC and nuts/bolts
>
> What can I do with the above and the internal tuner in my K1 without
> going out and buying anything? Ideally, I'd like something that will
> load well on 80/40/30/20/15 but will settle for 40-15.
>
> Anyone have any ideas?
>

Most of this will bounce since I am not subscribed to but one of your
cross-posted forums...

However,

There are several things you can do. You didn't tell us how much horizontal
space you have so I will just guess.

You don't have a balun or an external tuner so this will be fun to work
with.

You can try some of the following:

1: stretch out a 135 foot dipole (Inverted Vee) and feed it with the RG213
to the rig. Trim the antenna to match as close to the lower end of 80 as
possible. 3.525 or so should work. Then see if the rig can handle the
antenna on the other bands. It should work harmonically on all bands but 30
meters. If not, calculate the center frequency of the 80 meter band and trim
it to one whose multiple will put you closest to those other bands you wish
to operate. I am assuming you are wanting to operate CW mostly.

Once trimmed, then try to fine-tune it with the internal tuner to those
bands it doesn't match. If it matches all but 30, then calculate a 30 meter
dipole and add it under the 80 meter dipole. Use the PVC to space the
elements about 4-8 inches apart. Trim the lower frequency antenna first,
and then the higher frequency antennas. Now, you should be able to operate
on all bands.

If you don't have the space, you will have to be more creative. Trimming
the inverted vee to 7.025 will also give you a multi-band from 40-10 and
require less space. You may still need the 30 meter element.

If you could make a full sized dipole (flat-top), you can keep adding
dipoles under the 80 meter dipole until you have all the bands you desire,
each trimmed for your favorite frequency and the tuner will match it on the
rest of the band.

I don't remember if the G5RV uses the same or less twin feed as you have,
but you can look into that.

I hope this helps, if nothing else maybe it will stir up some thoughts that
bring about your solution.

73 for now
Buck
N4PGW

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JT Croteau-2

Re: [QRP-L] What antenna should I build?

I'd like to thank everyone who replied. Here is what I just finished
building and installing:

I only had 17' feet of ladder line, not the 30' I thought I had so
this antenna is probably extremely far from ideal. The overall
antenna is roughly 102' long in an inverted vee configuration. The
ends are only 8' to 10' off the ground with the center probably around
35' judging by the feedlines I ended up having to use. It is fed in
the center with the 17' of ladder line connected to some type of balun
I found in the junk box (I think it came with a G5RV kit many moons
ago). I then had to use a 20' piece of RG8X to extend it to meet the
75' of RG8U TRIAX into the shack.

Here are what the numbers from my MFJ analyzer reads. If someone
could translate all this for me into how this antenna will work at QRP
levels with my K1 and KAT1, I'd sure appreciate it.

1.810 MHz SWR=7.0 R=6 X=37
3.560 MHz SWR=8.1 R=5 X=21
7.040 MHz SWR=5.2 R=5 X=34
10.100 MHz SWR=4.6 R=101 X=124
14.060 MHz SWR=6.0 R=7 X=15
18.080 MHz SWR=3.7 R=146 X=80
21.060 MHz SWR=4.5 R=118 X=123
24.906 MHz SWR=3.9 R=11 X=10
28.060 MHz SWR=3.9 R=30 X=54

So how bad does this POS look?

Thanks

--
JT Croteau - W6FO - Canton, GA | K1 #292
ARS #2,147 | NoGA-QRP | SEDXC | ARRL
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Don Wilhelm-3

RE: Re: [QRP-L] What antenna should I build?

It looks like the KAT1 should be able to match it - have fun.

73,
Don W3FPR

> -----Original Message-----
>
> I only had 17' feet of ladder line, not the 30' I thought I had so
> this antenna is probably extremely far from ideal. The overall
> antenna is roughly 102' long in an inverted vee configuration. The
> ends are only 8' to 10' off the ground with the center probably around
> 35' judging by the feedlines I ended up having to use. It is fed in
> the center with the 17' of ladder line connected to some type of balun
> I found in the junk box (I think it came with a G5RV kit many moons
> ago). I then had to use a 20' piece of RG8X to extend it to meet the
> 75' of RG8U TRIAX into the shack.
>
> Here are what the numbers from my MFJ analyzer reads. If someone
> could translate all this for me into how this antenna will work at QRP
> levels with my K1 and KAT1, I'd sure appreciate it.
>
> 1.810 MHz SWR=7.0 R=6 X=37
> 3.560 MHz SWR=8.1 R=5 X=21
> 7.040 MHz SWR=5.2 R=5 X=34
> 10.100 MHz SWR=4.6 R=101 X=124
> 14.060 MHz SWR=6.0 R=7 X=15
> 18.080 MHz SWR=3.7 R=146 X=80
> 21.060 MHz SWR=4.5 R=118 X=123
> 24.906 MHz SWR=3.9 R=11 X=10
> 28.060 MHz SWR=3.9 R=30 X=54
>
> So how bad does this POS look?
>
>

Stuart Rohre

Re: Re: [QRP-L] What antenna should I build?

In reply to this post by JT Croteau-2

You need to use a tuner between your antenna and the radio to avoid the
radio cutting back power to protect itself from high SWR.

You might want to try measurements without the unknown balun. They might
be better! Don't get hung up on the need for balun without trying without
first. I did not use a balun for my first 18 years as a ham, and worked
just as good that way as now with a balun.

Stuart
K5KVH

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