It works - Winding my own BALUN coils

Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
Love it when a plan comes together.

Here are some images of my coil winding experiment. This is a 4:1 Current Balun. The expected results should be 50Ω source into a 200Ω load. This will be used for an Off-Center Fed Dipole. This is for my home system. Currently I have a 4:1 UnUn Balun (unbalance source to unbalance load) which works but is not the correct Balun. So I have to replace it and don't want (yet) to buy one.

First image is the meter reading. Second is the coil and resistor load.

meter.jpg


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Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
Update - The setup above yielded good SWR with some reactance (X) across the amateur bands. There was a rise in SWR around 10MHz with a continual rise up to 1.2:1 in the low VHF (54MHz) band.

After I put the coil in a container and cut the leads short, the SRW was flat (1.0:1) across the entire HF spectrum from .53MHz to 113MHz were it started to rise very quickly.

The balun has been installed in my current antenna that is 130' configured as an Off-Center Fed Dipole and produce excellent turner results. The antenna is too long for multiband use without a tuner. However, I can tell the tuner is happy with a 4:1 balun vs a 4:1 unun. I will be cutting and installing the new antenna next week. Will report back then.
 
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Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
A look inside the balun box.
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Here are the specifics:

The ferrite core is a FT-140-43. It is 1.4" in diameter and the mix is material 43. The wire is 18AWG solid copper. There are 8 wraps on each side of the core. This is a single core balun which is not recommend unless one is using a Common Mode Choke with this balun (which I am). The preferred method is to use a dual core (1:1 x 2 which will equate to 4:1). The dual core will act like a Common Mode Choke (how convenient). The ratings for this balun are power 100~300 watts which is limited by the core size. The 18AWG will handle up to 16 amps. So overall this balun is a good balun to use on standard powered systems (no linear amps).

I have taken down my 130' wire antenna and will replace it with a 66' OCF Dipole. This will allow me to operate on 7 MHz and above with and without the antenna tuner. Only those frequencies which are a harmonic of 7 MHz will work without a tuner. But I will use a tuner anyway.

Testing up until I took the antenna down has shown that I am getting out really well now. My receive is hampered by my Solar Panels on my roof with use an Optimizer in the system. The wiring of the Optimizer is in a big loop and spewing RFI/EMI all over the HF bands. The system is by Solar Edge. If you are a ham and want to go solar at your house, do not use Solar Edge systems unless you do not want to operate anymore.
 
Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
New antenna working. 40m @5 watts. Using WSPTNet software to see how my system is working.

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