VERSION II NOW SHIPPING, OMNI-DIRECTIONAL ANTENNA, PACKS AS MUCH GAIN AS 2 DIPOLES
Shipping from EU! Also check the new STAINLESS STEEL VERSION HERE!
Why is it so great?
Looking for a solution giving gain similar to 2 bay vertical dipoles with perfect omni-directional coverage and have some space available at the top of a roof or a tower? Than this is the antenna for you. 2-dipoles mounted at the side of the tower will not give perfect omni-directional coverage; this antenna at the top of a tower will. Produced to exacting standards using state of the art electrical and mechanical designs resulting in superior performance and long service life. When measured against a standard 1/2 wave dipole the ExterminatorII® delivers close to a massive 5.15 dBi (3dBd) gain across the entire FM Band. All RF connectors are PTFE components with specifications that exceed required ratings. Antenna arrives fully tuned and assembled the ExterminatorII can be installed on your tower or mast in a matter of minutes.
Remember to write your desired frequency during check-out under comments, we will tune your antenna for you. You can always tune your antenna alone with SWR meter and instructions. Note that although antenna is tuned at the factory it is sometimes necessary to make a small adjustment depending on for example nearby objects etc. Some parts may also move slightly during shipping so remember to re-tighten all screws. Antenna ships in fully assembled form, but the two sections are collapsed for easy transport. You will only have to release two screws and extend the two telescopic sections all the way to the two black marker circles, than fix the screws again.
What’s new in version II:
– Significantly improved connector assembly
– Several other small improvements
– Perfectly circular coverage when mounted on top of a tower/pole.
– Matches or outperforms 2 dipoles
– Easier to mount than 2 dipoles
– Not wideband, requires tuning (we do this for you)
– NOT SUITABLE for people who don’t know how to operate SWR meter or perform simple antenna tuning (take wideband dipoles or multi-bay systems instead please)
– Frequency range: 87.5 – 108 MHz (check our website for VHF TV version)
– Max power rating: 900-1000W (N), 3KW (7/16)
– Impedance: 50Ω unbalanced
– Gain: 5.15 dbi (Upgrades 1KW tx into 2KW ERP tx, 3dBd)
– Radiation (H-plane): 360° omni directional
– Polarization: Vertical
– Connector: “N” – 7/16″ DIN
– 6MHz Bandwidth at S.W.R. 2:1:
– S.W.R. at res. freq.: ≤ 1.5:1
– Feed system: Gamma match
– Tuning: Arrives pre-tuned (retuning by length adjustment and gamma match adjustment)
– Materials: Aluminum, PTFE, Copper
– Wind load / resistance: 305 N at 250 Km/h
– Wind surface: 0.28 m2
– Height (approx.): 3,5m (depending on frequency)
– Weight (approx.): 5,5Kg
– Mounting mast: 40mm
How much ERP will my transmitter have with this antenna in ideal situation?
1KW transmitter: Your ERP will be increased 3dB (2x), 1KW transmitter will give 2KW ERP*
2KW transmitter: Your ERP will be increased 3dB (2x), 2KW transmitter will give 4KW ERP*
(*) not taking coaxial cable losses into account
What is 3/4 Wave EXTERMINATORI® 1KW head only?
If you want to repair a broken antenna or make your own this head is quite an important element and is not so easy to do by yourself. You can buy this CNC machined head from us cheaply.
Although antenna comes pre-tuned it is recommended that you re-check the SWR before putting antenna into service, nearby objects can slightly de-tune the antenna!
1. If you received your antenna pre-tuned extend the two telescopic sections until the two black marker rings show.
If you are retuning to another frequency extend the antenna as shown below (loosen screws and extend the 2 telescopic parts).
If tuning for around 88MHz: Extend fully
If tuning for around 100MHz: Extend 50%
If tuning for around 108MHz: Extend about 25%
2. Mount the bottom part of the antenna to the intended metal pole and tighten with screws firmly
3. If you received antenna pre-tuned, do not loosen gamma rod.
If this is a new untuned antenna or if you are re-tuning loosen the gamma strap so that the gamma rod can move in and out with a bit of effort. Now set the rod so that it is about 1/3 in the black gamma match tube.
4. Connect RigExpert SWR analyzer (AA-230 or better), power it up, press 4 for SWR measurement. (read the PS below if you do not own one).
5. Move center frequency to frequency of choice (use Freq – and Freq + buttons), set range to about 20MHz for a start, you can reduce range later when you get close to the frequency of choice.
6. Press OK to start measurement. The curve minimum needs to be close to zero at the desired Frequency.
7. Change the length of the antenna until you get best SWR at desired frequency.
8. Change gamma rod position until you get best SWR at desired frequency.
9. Repeat 7 and 8 until you get minimal SWR reading possible.
10. Tighten all screws
11. Check SWR again. If needed, correct.
12. You’re done!
PS: If you don’t have antenna analyzer feel free to use SWR meter as well, however do this at minimal power that still makes it possible to get a decent reading out of your SWR meter and at the same time does not endanger the output stage of your transmitter. Never read SWR off the LCD display of your transmitter, USE A REAL SWR meter or antenna analyzer.
Important: Due to large size and irregular shape of these packages the website often gets shipping cost wrong. Also sometimes we have to use wooden case which adds about 100 euro to the cost of antenna. For exact shipping cost please contact our sales department, be sure to give them your exact address and they will quote you shipping.
Recommended accessories: Grounding kits can be purchased here, they ensure lightning protection. They should be installed at the antenna, at the tower base and at the point of entrance into transmitter building. Also use self-sealing tape on connectors, it fuses into rubber and protects moisture from entering your coaxial cable and antenna system.
This antenna is based on the old AVANTI SIGMA 4 or AV-174 design. An antenna first produced by Avanti, (The Antenna Specialist Co.) and cloned by many under various names. Lately it has been sold by SIRIO as Vector 4000. Antenna is most commonly seen on the CB band and can be found under various names like: Sigma IV, Vector 4000, CTE saliut lw 150, Targa BT 104, Q-82, etc. Though there are examples since 1996 available for other bands up to VHF region like FM broadcasting. Almost every present day CB user has heard of the antenna. In fact many have used or are still using the antenna today.
Most of the FM broadcasting band versions are actually produced for CB band and just modified to work for FM band radio. CB radio products are usually quite low-quality low-cost and they use very poor quality gamma match which is perfectly good for CB radio but when used at high power at 88-108MHz these blow fast. Those also often use cheap plastic connectors and parts, again fine for low power and CB but not 24/7 high power VHF broadcasting. Pretty much all of them use low-cost cast heads. Competition in CB world is very stiff and every cent counts.
Our VHF FM broadcasting band Exterminator antenna is also a version of the AVANTI SIGMA, but it has been built from scratch for FM broadcasting and comes with high-grade CNC machined head. Antenna is fully built for VHF FM broadcasting and not a re-purposed CB version. Check the photos. Connectors are all PTFE.
If you run into guys who sell these antennas and claim that they invented them even though the antennas are identical to the old AVANTI SIGMA design just ask them for patent number and see them struggle as they won’t be able to produce it. Some of them put up fake websites and launch smear campaigns to attack their competitors. We don’t. Everything written above is true. You can and should read about this very interesting antenna here, it makes for an interesting reading and is highly recommended.
Yes, full 3dBd is possibly a bit too optimistic to expect but it gets pretty close to two dipoles considering there are no combiners and no harness cables. Also less parts to break. Perfectly circular omni-directional pattern is a plus as well as there is no shadow from the tower seen with side-mounted dipoles. As this antenna is mounted on top of the tower it will likely be a bit higher than 2 dipoles would have been. All in all, our field tests indicate performance very close to two dipoles and in some cases exceeding two dipoles (shadow from the mast with dipoles).