Posted In: Technology
Hello everyone, I would like to ask more experienced Hams for advice on how to make a 1:1 current balun for an inverted V on 3.5 MHz. I have an AMIDON T200-2 toroid. I know there are plenty of guides online, but I don't know which one would be right for me. Power up to 100W. Thank you all for your time and valuable advice. Peter, OM6APJ
Sorry, I forgot to click the address there http://www.ok1cjb.cz/index.php?option=com_content&view=article&id=63:0-540&catid=16:zaizeni-vf&Itemid=4
Hi, try looking at this:
http://anteny.webz.cz/articles/cz/baluny_a_ununy_pro_KV_anteny.html
It's quite a comprehensive and interesting article.
Rado
I will also contribute, at this address is everything needed to make a dipole:
http://www.aa5tb.com/dipole.html – dipole antenna, calculator for calculating dimensions (foot = 30.48 cm), practical implementation of the antenna.
Peter, I am 31 years old, I transmit with antennas without baluns, try this solution and only then include the balun!
You 73!
Vilo, OM3CAQ
@om2zz wrote:
Hi, try looking at this:
http://anteny.webz.cz/articles/cz/baluny_a_ununy_pro_KV_anteny.htmlIt's quite a comprehensive and interesting article.
Rado
Somewhat dubious article. I don't know what this resolute warning is for, that ferrite cores should not be used. It is not possible to achieve sufficient inductance with iron powder.
A balun does not always have to be a transformer. Sometimes it can be just an inductor, with such baluns better results can often be achieved. I recommend the toroid FT-240-61, which is wrapped with Teflon tape (insulation) and on which 6 turns of RG-400 coax (Teflon diameter 5 mm) are wound. This works from 80 to 10 m and under normal conditions, 2 kW is not a problem. The core is saturated only by sheath currents, so the 2 kW applies to dipoles, quads, etc.
It is simple, but complicated at the same time.
Use a current guanella balun, but before installation, blow it with full power into the load and measure the input SWR and the output antenna current.
It should not change dramatically across the entire intended range.
Otherwise, the balun will be a problematic component of the entire antenna.
If you insist on a balun, snap on or thread ferrite cores onto the plastic and more in a row (at least 10) or coil the cable into several circular loops and secure with tape, or wind it onto a PVC pipe and secure with zip ties through the holes.
It will definitely work better than when you have no experience with adjusting and making baluns.
Voltage baluns have quite a small bandwidth and are problematic due to the materials used, such as iron powder starch and others.
Cores from switched sources are not very suitable for amateur operation, so perhaps for the 160m band, higher is already useless.
all of this is nonsense. A current balun, i.e., 1:1, is minimally stressed on the core, because if two symmetrical windings are made against each other, the entire core is only saturated by differential currents (i.e., minimally...)
Amidons are quite suitable for this, albeit expensive, but they work.
Amidon T 50-2 with 2x2x12 turns against each other covers 80-10 meters absolutely comfortably and without losing the 'flower'... max SWR is 1:1.5