Homebrew 40m 7 MHz antennas for amateur ham radio

 

This is a list of designs for any type of 40m 7 MHz homebrew amateur antenna

To refine your search to show only vertical, loop, wire, portable, multiband etc. click refine search for homebrew antennas


Showing matches 1 to 47 of 47

THE DOUBLE BAZOOKA ANTENNA

The Double Bazooka Dipole is a very efficient single band antenna which is very quiet and does not require the use of a balun. This antenna consists of coax (RG58) or other 50 ohm type with the shield split at the center and the feedline attached to the open ends.



Australian Broadband Dipole 2MHz o 30MHz with no ATU

A dipole can be modified by inserting resistive loading networks so as to produce standing waves between the feedpoint and the networks. The authors have, by adjustment of the networks and the dipole sections, developed a travelling wave dipole whose VSWR is less than 2:1 from 3 to 15 MHz and does not exceed 2.6 to 1 from 2.3 to at least 30 MHz.



The $4 Special Antenna



Sure, you can find "all-band wire antennas" for sale in the back pages of Ham magazines costing $150 or more. But beware
: Marconi spins in his grave every time a ham buys an aerial instead of building it. The plain and simple truth is that wire antennas for the HF bands were intended to be hand-made and not store-bought.

Untold generations of intrepid Radio Hams have fashioned their own equipment out of spit and bailing wire. Do you think the spark-gap dudes of the 1920's just went out and bought ready-built G5RV's from HRO or AES? No way! They slapped together aerials out of bedsprings, chewing gum, and frozen cow poop. For them, every day was Field Day. I think that home-built antennas should be awarded 10 db of "honorary gain" simply by virtue of their ingenuity. And in this world of microprocessor controlled micro-rigs, constructing one may be your only chance to build something and actually see it work on the air. Think about it.




9 band vertical HF antenna

Simple vertical radiator with a not so simple matching box. No traps, no tuner required.



The Fence Fan Dipole

A Quick, Easy and Inexpensive Multiband Antenna By W6HDG



FULL WAVE LOOP ANTENNA

Are you looking for an inexpensive wire antenna that makes possible HF operation on all bands 10M through to 80M with wide bandwidth? This Delta Loop is a threesided antenna suspended high in the air by vertical supports such as tall evergreen trees. Recommended height is 40 feet or more at highest point but higher is better. It's one feed line eliminates the need for multiple antennas to cover the HF bands.



Portable Magnetic Loop Antenna for 20m, 30m, 40m

A simple multi-band magnetic loop antenna designed for 20, 30 and 40 metres, but by changing the overall length of the wire coverage of other bands is feasible.



K3MT presents the GRASSWIRE - another approach to hidden HF antennas

Deed restrictions got you down? Neighbors intimidating your tower plans? Need a really easy portable HF antenna? Then
the grasswire may be the answer! Virtually invisible, lightweight, and compact (you can carry one in your hip pocket),
this antenna works! It has been used by K3MT in various installations for more than 10 years.



Skywire Loop Antenna

In we ham radio operators' continual quest for the perfect antenna system, we try some strange things at times, but often, the simplest is also the best. That is certainly the case with the basic "loop" antenna, an often misunderstood critter, but one that gives absolutely the most for each foot of wire of any antenna I have had occasion to play with.

First, let me reassure you that such an antenna does not necessarily take much room. One reason I went to one in the first place is because I didn't have room for a 260-foot-long dipole for 160 and I wanted to give the "top band" a try for the first time in my 45 years of being a ham. If you are talking 75 meters (and up if you
want a multi-band antenna...more later on that), it's only about 65 feet on a side in a square arrangement



HB9ABX RoomCap Antenna

Yet another new, revolutionary design which allows the construction of small
HF antennas which provide the same efficiency as large antennas.

(Maybe but probably not !!! - G6KIZ)

This antenna can be built for all HF bands, from 10 to 80 m.



10-80m MOBILE HF MULTIBAND ANTENNA PROJECT

This is
a combination center and top loaded multiband antenna. It gets a good boost in efficiency from the
capacity hat which, unlike the commercial bugcatcher antennas, is located where it should be: as high as
practical on the whip. The low profile of the capacity hat lets it cut through the wind while still remaining
effective. This is the largest diameter hat which can withstand highway speeds without using a stiffer whip.

Band switching is accomplished by moving the jumper plug to different tap points on the coil. You have
to stop, get out, and manually change the tap.





6-Band HF Center-Loaded Off-Center-Fed Dipole

The goal that I set out was to design an HF antenna, with a VSWR of 3:1 or less over the full bandwidth of as many amateur radio HF bands as possible, with a preference for the low- and the non-WARC bands. This design goal has been achived with a new kind of antenna;



160-10M Sturba Curtain

This design will work all bands from Top Band to 10M using a tuner.



Super Linear - Loaded Inverted V

How do you fit a full length 160 meter antenna into a 40 foot deep yard?
Install the KG0ZP Super Linear-Loaded Inverted V, of course!
This design can also be scaled to work at 80m and 40m



PA0RDT Mini Whip

Compact wideband active antenna.

Claimed effective from 10kHz to 30MHz

Specifications:
Frequency range: 10 kHz – 30 MHz
Power: 12 – 15 volts at 50 mA.
Second order output intercept point: > + 70 dBm.
Third order output intercept point: > + 30 dBm.
Maximum output power: in excess of – 15 dBm

Dimensions:
Length: 100 mm, diameter: 40 mm



A low cost fishing pole vertical antenna by G4AON

There seems to be a myth among many newly licensed radio amateurs that an antenna works better if it costs a lot of money. This may have originated from magazine reviews which appear to be written to keep the advertising revenue up rather than serving the needs of the reader. The antenna shown here costs around one tenth the price of a commercial vertical, yet it will perform as well as (and in many cases better than) a trapped vertical antenna.



The 40 meter Stealth Vertical

“You’re 30dB over 9 here…” S
o goes the consistently fine signal reports received from around the USA and beyond - on 40 meters at the peak of Sun Spot Cycle 23. The most common antenna used in ham radio mounted over poor desert soil conductivity still performs beautifully!



80/40m Vertical +160M at a push..!!

I have always admired the Butternut vertical antennae. They are very well built using good quality doorknob capacitors and nice airwound lowloss coils. Having had an HF2 for a while I decided to see if I could make a homebrew improved..?? version.



Portable HF Transmitting Loop Antenna

Small tunable magnetic loop antenna light enough to carry while operating, it disassembles into small but rugged pieces that fit easily in a backpack or gym bag, and it can be tuned from 14 MHz to 30 MHz.



Short dipoles and verticals from DJ9RB

Basic design details for a number of different antennas from 160m to 40m



THE $4 SPECIAL by Joe Tyburczy W1GFH

Now at this point, some of you may be looking at the diagram and muttering, "Jeez Joe, that'
s just a dipole fed with twinlead and used with a tuner". Well of course it is. Virtually all antennas are "di-poles" (i.e. "two sides") in some form or another. This one just happens to be made from low-cost materials.

I won't go into the theory here, but trust me: balanced feedline, properly used, does not "leak" RF and is less lossy than coax. I've tried the commercial 450-ohm ladder line, but prefer 300-ohm TV twinlead, and the cheaper the better. Radio Shack TV twinlead is ideal. Home Depot has some good stuff, too. Forget all the obsessive junk about standing waves, impedance and velocity factor. What you really need to concentrate on is getting an interesting set of antenna insulators.



THE CLOUD WARMER NVIS BEAM

AIM FOR THE CLOUDS AND GET BETTER "LOCAL" SIGNALS! AN NVIS STYLE "BEAM" ANTENNA FOR BETTER "LOCAL" AREA COVERAGE ON HF

Some of you may recognize
this design as nothing more than a half wave dipole, but upon closer examination, you will see that there is a reflector at the bottom of the antenna spaced at about .15 wavelength or less from the driven, (dipole), element. This in fact, makes this antenna a 2 element wire "beam" aimed straight up at the clouds! Hence the name "Cloud Warmer Beam". NVIS style antennas work best below about 8mhz as confirmed by the U.S. military.



N3OX "Stealth" Multiband Vertical

I traded lawn mowing for antenna permission at the house I'm renting now, but since I don't own the place, I'm not able to install big, heavy, or very permanent antennas. Despite the practical restrictions, I wanted to have a vertical for 40m and 80m as we slide down to the sunspot minimum. This is what I came up with, and got 60m and 30m essentially for free.



G5RV Multi-Band Antenna by Louis Varney,

THE G5RV ANTENNA, with its special feeder arrangement, is a multiband centre-fed antenna capable of very efficient operation on all hf bands from 3.5 to 28mhz, specifically designed
with dimensions which allow it to be installed in gardens which accommodate a reasonably-straight run of about 102ft (31.1m) for the "flat-top". However, because the most useful radiation from a horizontal or inverted-V resonant antenna takes place from the center two-thirds of its total length, up to one-sixth of this total length at each end of the antenna may be dropped vertically, semi-vertically, or bent at some convenient angle to the main body of the antenna without significant loss of effective radiation efficiency.



W5DXP No-Tuner, All-HF-Band, Horizontal, Center-Fed Antenna

The No-Tuner, All-HF-Band, Horizontal, Center-Fed Antenna is our old friend, the 80 meter halfwave dipole dressed up a bit. By varying the length of the 450 ohm ladder-line feeding the antenna, we can achieve an SWR of less than 2:1 on all frequencies on all HF bands with the exception of the lowest part of 80m. On 75m, we are feeding the antenna with a half-wavelength of ladder-line. On 40m, we are feeding it with 3/4 wa
velength of ladder-line.



St. Louis Vertical

The St. Louis Vertical (SLV) About 51' of twinlead is coiled on the 4' bottom section of a 20 collapsible fiberglass fishing pole. An additional 16' of twinlead in the clear serves as a vertical radiator.

Offers portable enthusiasts an easytobuild easytouse antenna which covers 1040M via a balanced line tuner and installs independently of external supports (trees are not required)




40m 2el short yagi

Shortened 2 elem
ent yagi for 40m



A Multiband Vertical

I have to thank Con, DF4SA, of Spiderbeam for giving me the opportunity to inexpensively try their new 18m telescoping pole. I turned it into a great 160m through 30m antenna; as a bonus it makes a good tree surrogate to hang a 15m dipole from.



The RXO unitenna

Wide band vertical antenna for 40 to 15 meters band



BUILD THIS MULTIBAND FAN DIPOLE FOR ALL BAND HF ANTENNA EXCITEMENT

The only construction effort necessary over a standard multi-band dipole is the fabrication of a feed block or center insulator that is about 12 inches vertically by 3 inches
wide, made of a good insulating material, such as Lucite, Bakelite, fiberglass, or PVC.



40M Triangular Full-Wave Vertical Loop Antenna

Add the Missing Leg to that InvertedL Antenna



QRP Fan Dipole

The object of the exercise was to produce an aerial that would allow me to operate from 40 metres to 10 metres specifically 40 20 17 15 & 10 metres. The antenna was always going to be mounted in the attic as no external antennas are permitted at my QTH the attic allows the antenna to 'beam' roughly northwest / southeast and the house is some 40 feet above sea level. Construction would be simplified by the fact that I intended to run a maximum of 10 watts which means that the antenna wires can be simply attached to the rafters.



3 HALF WAVE LENGTH HORIZONTAL VEE

The short vee beam described has a reasonable omnidirectional pattern with a maximum directivity in a line that bisects the angle between the legs. Good low-angle radiation is obtained when a horizontal antenna has a one wavelength height above ground. Below .5 wavelengths give marginal performance. For lower heights (.5 wavelengths and less), some improvement in low angle propagation can be had by tilting the leg ends below the center feed point. This will help improve DX but at the expense of the omni pattern not being as good and will increase the vertical pattern more skyward at a higher angle.



40 Meter NVIS antenna

This project gives enough information to build a 40 meter Super-Gain antenna designed to help hams compete somewhat better with the foreign broadcast stations which practically take over the band in the evening and night time. It is based on the theory of super gain NVIS arrays, which reject QRM from low angles.

The final design....still under testing by many hams....is extremely simple, uncritical and offers large gain and QRM rejection.

The propagation studies and design work was done at Dusina Enterprises in Melbourne, Florida.
The antenna is described
as having approximately 9 db forward gain and an average of 15db rejection against low angle QRM. The antenna is useful up to about 200 miles radial distance from the transmitter in the daytime and up to around 1,000 miles at night.



THE LATTIN 5 BAND ANTENNA

This antenna should be considered EXPERIMENTAL! Most builders who have atte
mpted to build it, report difficulties! More research by builders is needed on it's proper design!

The antenna was named for W4JRW who invented it and holds a patent on the basic principle and uses quarter wave stubs, which act as insulators at the frequency for which they are cut. For example, the 6'11" stub (quarter wave times the velocity factor 0.8 of the feed line used) blocks RF for 28 mhz from reaching the rest of the antenna.



80m & 40m DUAL BAND HOMEBREW 2 EL SHORT BOOM YAGI

The VE6WZ QTH is a small city lot so achieving gain on 80m has been difficult. Good DX results have been experienced using the Force1
2 EF180B 80m rotatable dipole at 100' so it was decided to design a 2 el 80m yagi around similar elements. The VE6WZ yagi design uses high Q mostly air core loading coils instead of the linear loading on the 68’ elements. Because of dimensional constraints at the VE6WZ city QTH a 28’ short boom reflector design was built with the 2 el 40m yagi sharing the same boom.



A Small Loop Antenna for Forty Meters

Small vertically mounted loop constructed from copper tubing. Rather limited detail for copycat constructors.



Super loop 80 antenna

The "trick" to the Superloop is the 30' length of ladder line hanging down from the center insulator. This length has been
tuned so that appears to be a open-circuit stub on 40 meters; thus the antenna becomes two full-wave wires (at 40
meters) and is commonly referred to as the Bi-Square antenna. On 80 meters, it appears to be a short and the antenna
becomes a single wave vertical loop. This happens automatically and no switching is involved.



G5RV 40m Beam Antenna

Adding a 28 ft. piece of vertical wire to one end of a traditional 102 ft. centerfed G5RV dipole turns it into a 40m beam with a very wide beamwidth.



DUAL LOOP - 80 AND 40 METER HF WIRE ANTENNA

The antenna is basically a full wave 80 meter loop on top and a 40 meter loop on the bottom all supported from a 64 foot center support, namely my tower. They are both fed from the center feed point with one length of 50 ohm coax. No tuner is required.



Battle Creek Special

Trapped wire vertical for 40m 80m and 160m



SM0DTK 40 meter Moxon

On my lot I have some pretty high trees (15 meters) which can carry wire antennas. So what antenna to hang up to get some gain to the west and to reduce signals from the east? My choice was to try a moxon wire antenna made by very thin wire to reduce weight. I started up the Moxon Rectangle Generator and calculated the dimens
ion for the antenna. Then I cut the wire according to the result from the generator and made some supports for the corners and for the feeding point by plexiglass.



The KL3JM modified "SRI" multiband fan dipole for 80-40-20 meters

The antenna in this project is a modification of the techniques used to design a multiband fan type dipole with little or no
tuning involved.



The Kite and Balloon Antenna Site

Kite and balloon lifted antennas for Top Band and higher from YB5AQB (Plus YI9CC and 9M2/G4VGO)



K4TX 40 Meter 2 Element Parasitic Delta Loop Switchable NE/SW

The Delta Loop array used at my QTH is a simple and inexpensive way to achieve substantial gain and reasonable F/B ratio. I took the idea from Dave Pietraszewski K1WA's article
in the ARRL Antenna Book when he wrote about 5 Sloping Dipoles suspended from a single tower. The sloper parasitic array he described had an ungrounded coax switch mounted in the tower. He used 3/8 electrical wavelength feedlines to each element. He would transmit with a single sloper & the other ones acted as reflectors. Why? Because the 3/8 wavelength feedline going to the other slopers (each being open circuited due to the ungrounded coax switch) added inductance making the element appear 5 % longer thus acting like a reflector.



IK0GDH 40 METER LOADED MOXON

This is a prototype and it is not a lightweight antenna.

I erected the antenna on a 9 meter test tower at my mother's home. The trial began. With only a few adjustments of the feed point on the driven stub, the antenna analyzer showed a close to perfect match, with overall SWR less than 2:1 over 130 Khz! The same operation was performed to optimize the rear F/B.



Vertical antenna for ham radio - 40 meter ham band

Spanish article. Extract from Babelfish translation...

This self-supported vertical antenna was made with aluminum tubes of 3 ms in length that have an External to diameter of 32 mm and to wall thickness of 1,2 mm total The length of the radiating system is 10,33 ms and its square-shaped bases measures 25 cm on to side.


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