Ham-Radio operator blog and resources from Firenze Italy, edited by IW5EDI Simone
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After evaluating HF vertical antennas I’ve finally choosen and ordered my new vertical hf antenna.
Gap Titan DX is the choosen one.
According to characteristics and price the Titan resulted the one with the best price / performance ratio.
I ordered at Wimo (german ham radio dealer) and it arrived in 3 days via UPS.
Best price and fast delivery, thanks folks at wimo.
More posts will come about antenna setup
After a long research on antenna makers websites I’ve produced a quick reference chart to compare most popular HF multiband vertical antennas.
This table will help me on choosing my next vertical antenna.
Populatrity of antennas has been decided by visiting eham reviews, qrz.com forums, and other local ham radio communities.
Price comparison has been done by quering eruopean dealers, and asking for better quotations without considering delivery costs but including VAT where needed.
Attached to this post you will find a PDF file with the full technical comparison.
Links to official web sites:
Download my Vertical Antenna Comparison Chart
As published in antennex Dec. 2001
The 40 Meters band stealth vertical antenna by K7ZB
“You’re 30dB over 9 here…” So 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!
Original article by K7ZB
Results
The simple 15′ vertical antenna shown mounted on the railing of our second floor deck has produced almost 200 countries worked around the world… VQ9’s in Chagos and 3B8’s on Mauritius in the Indian Ocean, TX0DX on Chesterfield Reef, VK0MM on Macquarie Island in the Antarctic region, BQ9P on Pratas Island off Taiwan, ZM7ZB on Chatham Island in the South Pacific along with FO0AAA on Clipperton, 9M0OO on Spratly Island in the South China Sea, JT1CO in Mongolia and on and on. What I hear, I can usually work with this little wonder and the small size and profile make it feasible for use in deed restricted neighborhoods.
A radio amateur friend and antenna designer came up with a simple design for a 10 meter vertical, which another friend and I modified to make work for the 14, 18, 21, 24 and 28 MHz ham bands. Its performance surpised us, and I’ll share it with you, in case you too are looking for a simple, inexpensive DX antenna that really performs well.
Main Antenna Concept
The basic concept is to put up a piece of aluminum tubing with a telescopic section held by a small hose clamp to adjust the height. By attaching the center conductor of a coax feedline to the tubing, and the shield of the coax to a couple of radials from the base of the tubing you can load the vertical across quite a broad range of frequencies.
Of course, with a vertical element of approximately 15′ this is a non-resonant antenna for the 10, 12, 15, 17 and 20 meter bands. I chose this length on purpose to allow the system to be tuned to resonance with an antenna runer.
Tuning
Since the SWR in an antenna system of this type will be relatively high, an antenna tuner unit will definitely be required. You may need an external ATU if the one in your transceiver can’t handle the impedance mismatches involved. Here at K7ZB, I drive my TS570 (which has a built-in ATU) thru the amplifier, which then drives a high power ATU to the antenna. I put the SWR/Power meter between the amplifier and ATU to ensure a good match for the amp, and in cases where I run barefoot without the amp, I can still use the ATU to assist the transceiver’s ATU in ensuring a good match.
In this way, everything is matched for maximum power output: from the transceiver to the amp, and amp to the antenna. And, even though the SWR’s are high at the feedline and the antenna, it doesn’t matter because the system is matched with the ATU.
Need a general purpose antenna on “6 – the magic band” ?
The J-Pole is an easy-to-build and inexpensive device that provides an omni-directional vertically polarised antenna without the need for a ground plane. In technical terms, it is an end fed vertical 1/2 wave which is fed via a 1/4 wave matching stub.
If you need more info or dimensions for other frequencies, check out the web on J-Pole antennas.
This construction will take your 1-2 hours and it will cost you about $25.
cost breakdown below is for the material actually used, longer tubing lengths may be required that inflate the apparent cost.
Materials :
1 x 6.1 metre length 19mmx1.5mm round aluminium tubing ($12.75)
1 x 1000mm length 16mmx1.2mm round aluminium tubing ($1.50)
1 x 200mm length 38×25mm rectangular aluminium tube (x 1.0mm wall) ($1.80)
4 x 12-23mm stainless steel worm-style hose clamps ($1.50 each)
2 x 16mm (tubing size) plastic chair tips ($0.70 each)
16 x aluminium pop rivets
50 ohm coax cable, eg RG58A/U, minimum length 3-4 metres
200mm x 32mm white outdoor conduit
Nylon cable ties etc…
I’m looking to setup a hidden / indoor antenna, and i’ve found a couple of interesting articles on hidden / stealth antennas
This small antenna can allow hams which lack space to install an antenna for 40 meters. This project has been originally produced by F6CYV. I’m going to test this antenna in the coming weeks. I will try to setup this inside my balcony.
According to his experience, using it form inside the apartament, european singals are all very readable, he has worked over 150 countries.
The antenna is made of 2mm wire.
The 2 coils are constituted by 18 turns of 2 mm wire, distance of tunrs is also 2 mm.
The diametre of the coils is of 7,8 centimeters.
The Feed of the dipole is done with a 75 ohms tv coaxial cable.
A 1/1 balun would be recommand for a correct feed of the coaxial cable to the dipole.
It is not necessary to use a coupler, it is enough to set the length of both extremities of
the dipole in order to have at 7.050 mhz a low SWR, and especially to pay attention what the lenght of the 2 sides of the dipole to be identical.
[tags]antenna,ham-radio,amateur radio,HF antenna[/tags]
G5RV verses Superloop 80
Many operators with small lots, a G5RV is what can fit for the 80 and 40 meter bands. The G5RV is 102 feet long and has a 34 foot
section of twinlead followed by coax into the shack, possibly with some sort of RF choke on the coax. The ends are typically supported by ropes up in
the trees. An 80 meter dipole would be about 134 feet long.
A tiny lot is limited in antenna potential and zoning laws prevent real towers.
RadioWorks “Superloop III” designed by Jim, W4FTU, and refined over the years, is a good alternative