NOTE: After looking back, this may more properly be called an unun for unbalanced to unbalanced.
I had a 9:1 balun for my SDR (Software Defined Radio) in use on the receive antenna port of my FTDX101D. The SMA connector and adapter were bulky plus connecting it to my EFRW (End Fed Random Wire) antenna, which is the best I can do at the moment. Since it seemed to work so well for receiving, I wanted something a bit better in the connection department. Obviously this balun designed for SDRs is not suitable for transmitting. I have nothing at the moment to compare this to except for the 60 foot long antenna stretching from the house to the back of the detached garage.
Cancer treatment interrupted my antenna farm development about three years ago. While I’m cancer-free, recovery from surgery is slow….very slow. So, antenna development will be one slow step after another.
The 9:1 balun as it came from Amazon
Since I have no current plans using this particular balun outdoors and wanted to easily swap wires, I decided to add banana jacks to this balun to make quick swapping possible.
I couldn’t center the holes due to the connectors already mounted. The terminal for the black ground jack wanted to contact the center conductor for the UHF connector so I moved it “down” a little. I then cut off a little of the terminal for the banana jack to be sure it wouldn’t short.
There’s a reason the holes are crooked and not centered
Here’s it all wired and ready to go. The hot glue used by the manufacturer was not holding the toroid. Maybe I’ll secure it later.
The black colored jack is the ground connection and the red colored jack goes to the antenna.
Top view of finished work. All it needs is to snap the cover back in place. Remember that there is a reason the jacks are not centered!
Now, how does it work? It works a little better than sticking the wire straight into a UHF connector on the back of the transceiver. The random wire takes a meander to my workshop and then to a mast at the back of the detached garage. If I try to talk on 10 meters, it trips the GFCIs in the workshop, even at 5 watts. It also turns the touch-activated light over the kitchen sink on and off as I speak. So, I don’t transmit right now!
Hopefully this makes sense! Getting organized is still a challenge at times. I’ll post on this again if anything noteworthy is found.
