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New and Improved 9:1 Un Un
10 August 2013 | by My latest antenna uses a 9:1 Un Un. That’s a funny word isn’t it. It means Unbalanced to Unbalanced. It matches an unbalanced coax feed to an unbalanced antenna. The bonus here is that I can operate on 7 different bands using the same 35 foot wire antenna!
I had to change antennas every time I changed bands the old way. I guess this means I’ll have 7 single band antennas for sale soon!
Un Un Mounted on my porch rail
Note the bungee cord in the back. It allows for strain relief when this antenna is mounted over a tree limb.
Torroid on the left and PL 259 on the bottom.
Reinforcing block at the wire end of the Un Un. Note the hot glue holding the block.
Strain Relief for the wire lug.
I’ll use this antenna in the park, portable. Strain relief keeps the wire lug from separating from the antenna wire.
http://www.earchi.org/92011endfedfiles/Endfed6_40.pdf
I got the diagram and physical layout here. I added the bungee for strain relief and the reinforced ends. The Reinforced ends allow me to mount this antenna horizonatally, from my condo porch to the nearby Live Oak Tree.
Jim Cluett, W1PID mentioned this un un kit in a recent post. Thanks Jim. Thank you to the ‘Emergency Amateur Club in Honolulu for the PDF for this project.
73 de AA1IK
Ernest Gregoire
5 Responses to “New and Improved 9:1 Un Un”
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This is my most favorite design. Have used it for many years with all sort of wire lengths. Before I got my KX3 it was with a FT-817, K2/10/100, Tentec Eagle + LDG 100Plus (Eagle ATU sucks), and my K3/100. Worked great on all bands. I have found 50 to 55 ft of wire to work pretty well, but longer and shorter lengths do to. I also have never found the need for a counterpoise on any band with any power. I used plane old radio shack RG/58 25 foot and no issues. This antenna is a winner and really loves my KX3
73
Harry K7ZOV
Someone in my former club put together one of these. With an 85 ft length of speaker wire on the roof of my former apartment…could talk locally on 60 M and use 80 M without any problems at all. Since I’ve moved to Colorado Springs a couple of months ago into an apartment…can’t even get a satellite TV dish installed per management. Does anyone know if this antenna could be used inside of an apartment running along the floor and on low power with my FT-450 with some speaker wire around 30 ft?
Don, To answer your question…Yes and NO.. The antenna should work FB in you apartment. That is the YES part. The NO or maybe part is the ATU, in my opinion since I had a FT-450/AT for a while, stinks. It barely handle 3:1 SWR. If you had a Z100plus or similar no problem. The next choice would be to look into the LNR/PAR family of EndFed antenna. Once the wire length is cut to 1/2 wavelength the no ATU is needed… Hope the info helps
73
Harry K7ZOV
Thank you Harry for answering the question! I forgot to mention that my 450 is one of the original ones without the tuner…so I bought an LDG Z100 Autotuner when I got it.
Looks like I’ll get that speaker wire out…get the 450 and the rest of the gear setup and get back on the air.
Thank you again!
73
Don AE7QL
I have a similar setup that I use portable with my KX3 many lunchtimes at work. I attached everything to a 31′ Jackite pole.
You can see pictures and a write up on it on my blog here:
http://www.n0hyd.com/p/portable-qrp-antenna.html
Really like this setup! I can just about work anyone I can hear.