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CB 11 meter 1/2 Wave Dipole. ALL STAINLESS With 1:1 Current Balun, TRUE 2.15Dbi
$ 26.39
- Description
- Size Guide
Description
Designed by Nelson Antennas (KD8UJM)For maximum DX'ing on AM or SSB
First, please look at all pictures for helpful details and please read my entire listing. The bottom has GREAT information to maximize your radio station
The Half wave dipole has been considered one of the best all time antennas for both local and long distance DX contacts.
This 1/2 Wave dipole includes a built in custom built 1:1 current balun that isn't just a wide banded universal multi band balun but optimized for the 11 meter CB band frequency area. The balun will handle 500 watts without issue.
All Stainless steel hardware for many years of trouble free service. Stress reliefs on all stress points as you can see. Includes UV protected nylon dog-bone insulators. Standard but very high quality SO-239 connector to mate with your coax PL-259 coax connectors. The enclosure has a very small upward flowing air inlet hole with a tiny "weep hole" at the bottom ensuring condensation with temperature changes can always escape the system. Elements made with Marine 18 AWG tinned copper insulated wire can handle 2kW of power but also provide a nice thin/small footprint. Depending on my stock, dog-bone insulators will either be white or gray.
Power Handling 500W PEP
Antenna Length Approx 16 feet
Antenna True Gain 2.15dBi
Effective Radiated Power @2.15dBi gain 12 watts in = 19.7W ERP
Antenna Radiation Pattern Omnidirectional
Element Material 18 AWG Marine tinned copper insulated wire
Bandwidth 26.965 through 27.405MHz
Typical SWR 26.965 (ch1) = 1.3 or less
27.205 (ch 20) = 1.1 or less
27.405 (ch 40) = 1.3 or less
The importance of a
proper
1:1 current balun on a dipole;
A resonant half-wave dipole is typically fed with coaxial feedline and tuned to a specific area of a band. Its planned use is generally within that band. A popular misconception is because the dipole is resonant, or because the dipole feedline is small in diameter, a balun is not helpful. Current baluns isolate or add impedance to unwanted common-mode current paths, reducing or controlling common-mode current. Current baluns are the balun of choice in all but very specialized situations, because they work better than voltage baluns in most real-world systems. Basically, they ensure that the currents on each side of the dipole (balanced antenna) are perfectly even. This also stops unwanted currents from flowing on the outside of the coax (all coax is unbalanced line) and traveling back to your receiver.
This ensures a "clean" system without unwanted RFI issues.
How to deploy this antenna for maximum gain:
To achieve highest gain and Best operation 1/2 wave dipole should be mounted 1/2 wavelength or 17-20 feet high. This will give the rf the best low angle radiation for long distance DX. It will work fine at lower heights but for highest gain 17-20 feet is best.
The center of the antenna has a stainless eye-bolt at the top for it to hang from a support. Pull each leg of the dipole straight out flat and secure by tying your cord/rope to the dog-bone insulators. If securing the antenna to objects like trees that will move in the wind be sure to use a cord material with some stretch. You can also leave just a bit of slack in the system.
As with ALL antennas, you should install them in an area as open as possible. Obstacles close to the antenna will have an affect on both the tune of the antenna and radiation pattern. You cannot mount this or any antenna up against walls and such.
Coax selection helpful hints/ tips:
Remember, all coax has losses. Losses in coax are equal in receive and transmit! A very good rule of thumb to maximize your radio station is to have 1dB of coax loss or less. Here is a small chart of popular coax sizes recommended depending on the coax length for the 11 meter band.
RG58 coax at 27MHz
25 feet has .495dB loss, 50 feet has 1dB loss (borderline), 100 feet has 1.98dB loss (not good at all)
RG8X coax at 27MHz
25 feet has .388dB loss, 50 feet has .776dB loss, 100 feet has 1.552dB loss (not good at 100 feet)
LMR400 coax at 27MHz
25 feet has .158dB loss, 50 feet has .316dB loss, 100 feet has .633dB and 150 feet has .949dB loss (great to 150 feet)
Here is what coax loss does to your system
Radio output power 100 watts for ease of calculation
50 feet of RG58 coax at 27MHz losses are 1dB so only 79.6 watts of the 100 hit the antenna.
Now if you used LMR400 coax at 50 feet the losses are only .316dB so of your 100watts out, now your antenna gets 93 watts of your 100. Much better right? A good coax system is very important!
Any questions? Please feel free to ask. I am adding many more antennas and other antenna related products to my eBay store so please check them out from time to time.