I live in the country with 2 acres at my disposal . But I didn't want some big monster antenna on 160. In the 1990s I bought a W9INN Half Sloper with a 160 meter coil. It was a very simple concept. You take it to the top of the tower but under your 3 element beam ( which creates capacitance on the grounded side). Then obviously you load the center of the 50 ohm coax to the wire and slope it back down . Mine is about 66 feet to the coil ( it also works on 80 meters) and then at the W9INN coil you have about a 15 foot tag end for a nice 75 footer coming off the 50 foot tower. Much better than a 133 foot wire but if you have room that would work.(with trimming)
Every beam and tower (guy wires are ok) create great variable to make it fun but there is resonance at the end of your effort.Just cut and trim.
I'm certainly not the first on this antenna but I do add a rather stunning modification. The antenna can be loaded at the bottom end. in that case radials are added and it really becomes a slanted 1/4 wave vertical , W9INN made that suggestion in his instructions. The instructions are no longer shown on line. He is an SK.
My thought was-- what if I put radials at the base of the tower to cut ground loss. It was amazing. My 160 meter signal was much better. I worked 7 new countries in Europe in one night with 350 watts on cw (that is my maximum output with my little AL 84 Ameritron linear because my big SB220 doesn't go there) .
I only have 12 100 foot radials out now and I bend them around the house and every which way. But get this!! My signal was better off my tribander!! ( Hygain explorer 14) . Have studies been done on this?. Look I have been a ham 53 year. I have 342 countries confirmed and 1750 Challenge band countries. I'm not making this up. When I radialized the tower with ground radials, I definitely enhanced my signal on 20,15 and 10. There is no doubt about it. Yes, it is not demonstrable, it is anecdotal. . I have a friend ,NM5Y, who has noticed improvement when he radialized his 160 meterL offset from his 90 foot tower with his Steppir beam up there. . This needs field testing which I will not do but I pass it on for further testing. and thinking. Something is happening which I speculate is LESS GROUND LOSS of the radiated signal.But the half sloper vastly improved!!
Any way , back to the half sloper. Here is a quote from from a reflector with his Hams experience with the 160 meter half sloper.
Every beam and tower (guy wires are ok) create great variable to make it fun but there is resonance at the end of your effort.Just cut and trim.
I'm certainly not the first on this antenna but I do add a rather stunning modification. The antenna can be loaded at the bottom end. in that case radials are added and it really becomes a slanted 1/4 wave vertical , W9INN made that suggestion in his instructions. The instructions are no longer shown on line. He is an SK.
My thought was-- what if I put radials at the base of the tower to cut ground loss. It was amazing. My 160 meter signal was much better. I worked 7 new countries in Europe in one night with 350 watts on cw (that is my maximum output with my little AL 84 Ameritron linear because my big SB220 doesn't go there) .
I only have 12 100 foot radials out now and I bend them around the house and every which way. But get this!! My signal was better off my tribander!! ( Hygain explorer 14) . Have studies been done on this?. Look I have been a ham 53 year. I have 342 countries confirmed and 1750 Challenge band countries. I'm not making this up. When I radialized the tower with ground radials, I definitely enhanced my signal on 20,15 and 10. There is no doubt about it. Yes, it is not demonstrable, it is anecdotal. . I have a friend ,NM5Y, who has noticed improvement when he radialized his 160 meterL offset from his 90 foot tower with his Steppir beam up there. . This needs field testing which I will not do but I pass it on for further testing. and thinking. Something is happening which I speculate is LESS GROUND LOSS of the radiated signal.But the half sloper vastly improved!!
Any way , back to the half sloper. Here is a quote from from a reflector with his Hams experience with the 160 meter half sloper.
"I run a 68 foot half sloper (1/8 wave length on 160 meters) mounted on my 40
foot tower, and really have a blast on 160 with it. You can see my antenna
in the March 1998 issue of QST.
Here are a few different lengths for your sloper, and a few different coil
locations. Efficiency is not as good with the coil at the feedpoint, but I
found it very convenient to place it there for my situation.
I calculated the values below using 14 gauge wire as your sloping wire. The
formula I use is right out of the ARRL antenna handbook (Limited Space
Section). The handbook also has a chart that yields similar values. I
calculated the antenna for 1.8MHZ. You can just shorten the end of the
sloper to make it resonate up higher in the band.
For coil at feed point :
Coil Coil
Half sloper length XL (ohms) L (uH)
80 feet 376 33.25
70 feet 484 42.80
For coil at mid point :
Coil Coil
Half sloper length XL (ohms) L (uH)
80 feet 731 64.6
70 feet 927 82.0
Let me know what kind of coil form you want to use (diameter, gauge wire,
etc.), and I can give you some different winding combinations for the coil.
I had no problems getting my 160 meter half sloper to resonate, but the half
sloper is dependent on many factors such as ground, top loading on the tower,
etc, so be patient.
I am sure Tom (W8JI) and many of the other big guns on 160 meters laugh when
they see such designs for antennas. Nevertheless 160 meters sure is a fun
band and I recommend putting up anything that will get you on the Top Band.
73's
Don Kirk (WD8DSB)
Don,s opinions and experience are very close to my own.
You can build your own loading coil,
There are numerous articles and internet articles on the subject.
This is not rocket science. Good Luck!!
I want to add something here. If you are NOT good with the coil concept, do this-- Let's assume you have a 40 foot tower and some kind of beam up there to create the capacitance. Cut the wire 130' and ground e t coax to the tower similar to above. It will work. !! ( if you trim to resonance , I promise. But let's assume your lot is short. Go to the deepest fence line and BEND IT. 160 is coming back with the lessening in Sun spots , Get ready. Try the radials at the base of the tower if you want to but it will work either way. Write me at w5zo@arrl.net. Have fun -- MAKE NOISE! Mike
