This is the successor to our very popular 4113ocf combo balun and an instance where you really do get the best of the both worlds. By winding individual cores as 1:1 choke baluns and then cross connecting them to make a 4:1 current balun, we achieved the ultimate balun combination to build a multiband Off Center Fed dipole around.
If you look closely at the pictures, you can see the individually wound cores that form the combo balun. Each core has 10 individual turns to generate maximum choking impedance and produce near perfect transformation. The black polymer spacer is used to insure proper separation of the individual baluns at all times. The balun also includes the Top Hanger Eyebolt so you have a complete package for your antenna project.
This design offers several advantages over competitiors models:
- Choking impedance that peaks at over 5000 ohms for each conductor
- Power handling of 5kw
- Individually wound core for each conductor
Please review the test scans below to appreciate the excellent specs this balun offers.
Click to Enlarge
All testing done with an AIM-4170c Network Analyzer and precision 200 ohm load
If one or both legs of your OCF dipole will be installed over or close to (< 20 feet) your house, a large structure (garage, barn, etc) or near (< 30 feet) a metal roof/structure and you will run 700+ watts, DO NOT use this 4115ocf balun. The interaction/coupling of the antenna with the structure and or metal will create excessive flux in one core and subsequent damage to the balun. Instead use the Model 4114ocf which utilizes a single stacked core designed to handle the imbalance caused by any interaction or coupling.
There are a number of interesting designs for OCF dipoles available on our website
listed under the "Support & Downloads" tab at the top of the page
Custom mix toroids with low permeability provides broadband coverage from 1-54MHz. Epoxy coating for long term durability.
The design has excellent low frequency response which makes it very efficient (99%). Input impedance remains essentially flat across the full HF frequency spectrum.
Individually wound cores with windings of 14 gauge Superior Essex Heavy build polyamideimide "Allex 240 Winding Wire" wire inserted in Teflon tubes. This is NOT the enameled type (Formvar) used by less expensive competitors. It is coated with a polyimide covering rated at a minimum of 2kv breakdown voltage. Overall breakdown voltage is 10kv created by the combination of this special wire and Teflon tubing.
Insertion loss is < 0.1db
SO-239 connectors are silver plated with teflon insulation.
All hardware is Stainless Steel. Eyebolts are 1/4"
N connectors and alternate mounting options available in the accessories section.
The balun is installed in a weatherproof 4" X 4" X 2" NEMA Box with only small weep holes at the base to allow escape of condensation. Balun should always be mounted with the SO-239 in the down position.
This design can also be built with 1/4 inch studs in place of the side eyebolts.
Please be sure to choose your connector preference carefully.
E-mail a friend about this item.
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