160m 1/4 wave inverted L
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- เผยแพร่เมื่อ 24 ส.ค. 2024
- My inverted L wire broke a few weeks back in a storm with high winds. I've also had issues with the stake holding the feedpoint pulling out of the ground so I have installed a pipe with 40 lbs of concrete. Both trees have stainless steel pulleys so the counterweight will move more easily when the trees move.
I used my nanovna and put the data into simsmith to determine my inductor and capacitor values then spread the inductor to fine tune it. It is resonant at about 1.840 giving me both CW and the bottom of SSB before the amp starts to get unhappy. There are about 40 radials of various lengths that lay on the ground and will get pulled up in the spring when it's time to mow. As you can see I have some landscaping work to do in the spring as well.
N9TTK
160s are always a challenge. I am trying to figure one out myself. WD9O.
Можно было удлинить горизонтальное полотно до получения R=50 Om, и далее скомпенсировать реактивность конденсатором. В согласовании останется один элемент вместо двух. У меня spider beam pole 12m работает на 160м. Вертикальная часть 12м, горизонтальная 38-40. Одно но-с берега океана. 😊
Дальний Восток?
@@User-DX-radio in50nd
Thanks. N0QFT
I’m looking at building the same antenna. Have you experimented with less radials? Just wondering the noticeable difference. 73 w4zxt
Hi Jay, at one point I only had 8 short radials on this antenna. I was able to work EU with it still so put down what you can, your performance will increase with more radials. I still only have a handful of long radials with the majority being 16-35ft and the long ones being 100-140ft. I ran this antenna without the matching network for over a year because the lack of radials provided a closer match to 50 ohms. With the radials I'm about 25 ohms where X=0, the LC circuit brings that back to 50 ohms to make the amp happy. The low band dxing book by ON4UN is a fantastic resource as well as W8JI's website. Also checkout the K2AV folded counterpoise, I know a lot of folks running that system, I just don't have the room for it. That would take place of the ground radials but needs to be elevated. N9TTK
@@N9TTK thanks man! I’ve tried the elevated radial system but only with a city lot I decided to lay a few 160 ft radials under the wire. Looks like you have 45-50 there which is great. My antenna is a 80-10 efhw bypassing the unun as inverted L but only 30 ft high. I need to find some scrap wire somewhere and lay more. Lawn staples absolutely wear my back out hehe. Great info! I try to work at n4ss during top band Cw contest. Bryan uses this antenna at 120 ft with 64 radials and beverage antennas to eu ,ja and vk. Pretty amazing how well people hear the antenna that we can’t hear without the beverages. Maybe one day I’ll have a place in the country. 😆
How many turns on your coil and lenght?
Sorry I missed the comment, the box is 4 inches wide so the coil is probably 3.5 inches or so and maybe an inch in diameter. I used the sim smith program to determine the inductance needed and an online calculator to give me a rough idea of the coil. I used an LCR tester to get it close and then spread the coil once installed to fine tune the antenna. It is not perfect as I needed around 1300PF and only had a 1000PF doorknob cap. It's close enough and seems to work well.
💯👌🙋♂
Also meant to ask how long your radials are. Tnx
Hey Jay, I must have missed the comment. The radials are various lengths. Many short 16' radials leftover from my vertical, there are also 33' and some that are 132' or so. I tried to spread them out so the long ones aren't all going the same direction.
Could you use an air variable capacitor?
Yes you could for sure, I operate in the lower part of the band so no need for me to adjust.
@@N9TTK thanks!
Jeff W3AAB