Topics For Technicians!
THE KL7JR 5 BAND PIPE VERTICAL
It is designed for portability for field days, camping, or permanent installation, cost, and to achieve at least 1/2 wavelength on the WARC bands.
You will not believe it's performance until you try it!
1 ea 10 foot 3/4 inch EMT conduit
1 ea 10 foot 1/2 inch EMT conduit
1 ea 102 inch CB whip
3 each hose clamps
Assorted bolts, nuts from junk box
Insulating support for base of antenna (3 inch)
Assorted # 12 wire or plumbers tape for radial ring
4 to 6 or more radials + - 16 feet long from wire for each radial
NOTES and BUILDING TIPS: (See drawing above)
It is assumed that you will use a good tuner with this antenna and low loss coax with short runs. Cheap RG-58 types of coax is not recommended. As designed, the swr will be high on the bands since this is a non-resonante antenna so an external tuner will most likely be needed. The internal tuner on your radio may not have enough range to work properly.
Slide 1/2 inch EMT pipe into 3/4 inch EMT pipe 18 inches
Drill and bolt or pin above sections together. (Assure that you have good electrical and mechanical connections between all sections)
Hose clamp the CB whip on the outside surface of the 1/2 inch EMT section assuring that it overlaps 12 inches with the 1/2 EMT for a total length of all 3 sections for a total of 26 feet top to bottom.
Use some form of insulator on the base to isolate the antenna from ground.
Build your ground and radial ring from about 12 inches of wire and lay around the base of the antenna.
Atttach the radials, as many as you can lay out.
Attach the center conductor of your coax to the base of the antenna and the shield to the ground ring where radials are attached.
Raise antenna (See Antenna Raiser Project) and support....you may need to guy it with rope if windy.
Connect to tuner and rig...........ENJOY!
THE KB4BLM VERSION OF THE 26 FOOT VERTICAL
Up and ready for action in 2013! Notice whip at top is hardly visible!
Stainless steel sink strainer used as the radial plate. Cool idea!
Homebrew tilt mast with "Ugly Balun"
I completed it with all the little things needed. Its seems to work like a champ and tunes all bands with the internal tuner on the TS570D... don't need the external MFJ 993B tuner... how 'bout that???
Swr readings below taken from my Rigmaster AA-54 analyzer:
7.110 5:4:1 14.225 9:0 18.110 7:7 21.275 3:5 24.930 5:5 28.300 7:2
7.125 5:2 .250 9:1 .120 7:7 .300 3:5 .950 5:4 .400 7:3
7.175 4:9 .275 9:2 .140 7:7 .350 3:4 .960 5:4 .500 7:2
7.200 4:8 .300 9:3 .150 7:7 .400 3:3 .970 5:4 .600 7:1
7.300 4:3 .350 9:3 .168 7:7 .450 3:3 .990 5:4
The only band my TS570D won't tune is 12m and the very top freqs of a few bands. I don't know if the above swr numbers are "normal" for the antenna or if unusually high. As you notice, some start higher at the lowest freq and others just the opposite.
So, cost breakdown --- two hunks of emt, 102 length of 3/16" ss "whip" $15.00...ss bolts & nuts $6.00 ...#8 wire for lighting protection $5.00 . All the rest either existed or rescued from junk box.
I located it in a spot not visible from the street and the whip is thin enough not to be readily seen. This antenna is almost as easy to make as tree hung wire dipole, especially if one doesn't have a 66 foot tree. 73 from KB4BLM LEE!
"I wanted to thank you for your article about the 5 band pipe vertical that I found by accident onhamuniverse.com. I have just returned to the radio after a very long absence and have been making do with a short dipole on the roof (CCRs). While it has been good for casual things, it really lacks for DXing and contests, which are both things I want to pursue more seriously in the future. A week ago I decided to try to make a vertical that I could "sneak up" in my backyard for contests like this weekend's ARRL Int'l DX SSB. Yours was the plan I used. Spent a day gathering parts, and another putting it together. Finished it Friday morning, contest started at 5PM Idaho time. My wife helped me lift it onto the quickie mount I made in the backyard. We guyed it because we were expecting a storm Friday night. I set out 10ea 16 foot radials and a couple 32 footers.
John, you already know how well it works, but I was taking a gamble... my wife was pretty skeptical about conduit, clamps, a CB whip, and a bunch of wires all over the backyard. But I have to say, the performance was much better than I had hoped. I wasn't able to work the entire contest time so my numbers aren't large by any means, but I ended up with 88QSOs on 4 bands, 11,233 points, and (I think) 28 countries. All continents but Antarctica. What a hoot! 100 watts from Yaesu 450 and an AT-200 tuner. From SW Idaho (not exactly DX paradise hi hi).
I wanted you to know you've added to my enjoyment of the hobby.
I'll listen for you on the bands.