early into my antenna building I used ladder line and a step down transformer and a choke. everything was going great at about 1000w. a few minutes later the swr went bonkers and I couldn’t get it tuned. I open the toroid box and looked like Chernobyl inside 😳
Run into this myself; great advice! I've heard some say that doing that will upset one or more of the other bands but I did not have any problems when I lengthened mine. Would be interesting if you could seep your other bands just to see. In theory couldn't you possibly have a bad resonance? Thanks and 73...
I would think 130 feet would be one to avoid since it's 1/2 wavelength on 80 meters. I would bump it up to 150' or so. Also bear in mind that the antenna length and configuration will influence the feeder's resonance but at least we have a good starting point. Most material I've read says to start with around 42 feet but that's often too short. 90 to 100' works for me.
Nice video Steve. Is your loop antenna a length a full wave length for 75 or 80? I know that is not the point of the video... but I was curious about the loop length. Also, can I check the balance of the ladder line with a cheap Mini60 analyzer? or does it need to be the rig expert? This video has answered many questions for me. 73 - K1QS Kelly Ellison.
So . . . Are you saying that you use a balun to do what I use my tuner for ? And it would have been all fine and dandy if your 600 ohm ladder line would not have been resonate @ 3.7 Mhz ?
I use a Dentron MT-3000A tuner , it does have a built in 4:1 balun but is only in line when in the Balanced Line position . I have a home brew dipole (75m) fed with 300 ohm up to the Shack, then I use a 3' piece of LMR400 into the coax position on the tuner . So I use the tuner but not the balun . I have not had any issues not having a balun and I'm just wondering if I should be ? Thanks , Steve
This is very useful to know, thank-you. Amazing the difference a resonant frequency makes.
Thanks Steve. Moving to a new location and using 600 ohm feed. I will keep this info in and may save me a lot of headaches. N4GID
Nice. Very nice
Perfect explanation Steve. 73 OM
early into my antenna building I used ladder line and a step down transformer and a choke. everything was going great at about 1000w. a few minutes later the swr went bonkers and I couldn’t get it tuned. I open the toroid box and looked like Chernobyl inside 😳
Run into this myself; great advice!
I've heard some say that doing that will upset one or more of the other bands but I did not have any problems when I lengthened mine.
Would be interesting if you could seep your other bands just to see. In theory couldn't you possibly have a bad resonance?
Thanks and 73...
Thank you, this was very educational and well explained. What are some good, non-resonant lengths of feedline between 100 and 130 feet in length?
100-105ft is the most common used length for 80m to not have 2 waves married.
I would think 130 feet would be one to avoid since it's 1/2 wavelength on 80 meters. I would bump it up to 150' or so. Also bear in mind that the antenna length and configuration will influence the feeder's resonance but at least we have a good starting point. Most material I've read says to start with around 42 feet but that's often too short. 90 to 100' works for me.
Nice video Steve. Is your loop antenna a length a full wave length for 75 or 80? I know that is not the point of the video... but I was curious about the loop length. Also, can I check the balance of the ladder line with a cheap Mini60 analyzer? or does it need to be the rig expert? This video has answered many questions for me. 73 - K1QS Kelly Ellison.
Nice video Steve,
What happen with your EFHW-Antenna?
Is the Loop the only antenna you have?
Best 73
Martin
I still use the efhw mostly for 160m.
So . . . Are you saying that you use a balun to do what I use my tuner for ? And it would have been all fine and dandy if your 600 ohm ladder line would not have been resonate @ 3.7 Mhz ?
What tuner are you talking about and does it have a balun?
I use a Dentron MT-3000A tuner , it does have a built in 4:1 balun but is only in line when in the Balanced Line position . I have a home brew dipole (75m) fed with 300 ohm up to the Shack, then I use a 3' piece of LMR400 into the coax position on the tuner . So I use the tuner but not the balun .
I have not had any issues not having a balun and I'm just wondering if I should be ?
Thanks , Steve
@@daviddahlgren9603 You should be having issues but since you don't then forget about it.