Great info, appreciate the video! Got 100ft of RG 213 from my Buddy, doing the math around 96ft should be nulled on ch20, put an end on it, nulled for channel 40, called it good. It will very, put a meter and nulled jumper in line and came down some.hopefully with driver and amp it will be spot on. Thanks for sharing!
I called and remember talking to you on the phone about these tuned jumpers along time ago. And then I started trying it on my own. I think I made more of around the 6' length and one that was around 12' in length. My question is what do most people run into their own setups? Is it the 6' or 12'? Or will it hurt if it was a mix the lengths at all?
With a properly installed radio/antenna system, the radio is 50 ohms, the cables are 50 ohms, the amp is 50 ohms, the meter is 50 ohms, and the antenna feed-point is 50 ohms, the length of the cable need only equal the distance to connect one device to the next. No more no less. When the device impedance at both ends of the 50 ohm cable are matched to the cable impedance, the "cable length don't enter into it" except for maybe minor loss in the cable..... Since there is no standing wave or reflection with a matched system, the impedance along the cable stays the same (50 +j0), except for minor cable loss. Now if the antenna is mis-tuned, then you can try to adjust the cable length to make the radio "see" 50 ohms into the antenna/feedline system.. But, you be using up a lot of connectors and solder, measuring and cutting. Better to adjust the antenna length or position for best match (low swr). This video showed the extreme impedance mismatch of open or "infinite" impedance at 28 Mhz. When you put this "finely tuned 1/4 wavelength cable" in line to your unknown system impedance, cutting the length without knowing the actual system impedance, is futile, and unless your antenna has parted from the feed-line, the antenna feed point impedance is NOT infinite (open), it is some unknown value between open and short. A 1/4 wavelength trimmed coax, as shown here, is commonly used for "stubs" to filter unwanted frequencies, or while installed in a feedline system can be trimmed for matching. It has to be installed in the antenna system while trimming to be effective.
Thanks for watching. How ever you want break it down is up to you. It works way better for what I do. I'm sharing it proven over over on my gear. Thanks!
Dang buddy you make that look easy hope to get one of them tools cool thanks for this video Big Guy 👍 as always thank you for what you do for us and the hobby!!!!!!
I’ve learned how to do it , I’m slow at it but I’ve gotten very efficient with PL-259’s and .400 size coax But I don’t know if I’ll ever learn or have the patience to deal with the bigger coax and connectors like you done for me on that Heliax 73 ,, and great info !
Ya, that is different than I normally do it. Looks like a better way. I always had to fight getting the ground soldered and never thought of pre soldering the ground. Do you do it in 3ft increments.
Good video my rig expert is on its way I’m afraid of what I’ll find on my a99 and coax run. Curious, do you have some recommendations for flexible coax to use on jumpers? Most I’ll be running through them for now is about 1kw peak but with all the jumpers I gotta make up the rg400 is out of budget after that analyzer purchase.
Because it works....More less hiding the coax in line. Anything you put in line changes SWR, OHM, Impedance were its another amp meter switch box etc. If your big ham op with a HF rig with built in ant tuner it can take care of it for you. Thanks
I did not measure it exact, Start at 6'4 first one cut it down with a analyzer. Remember different brands, types of coax will all be different. Even coax ends.
261 Canyon Hopper southeast Utah waving a hand, I’ve got a question for you on nulling coax, does it matter weather you short the end out to get your R-x down where you want it vs just doing it open? I’ve done it both ways and get great results so I’m assuming it is good
I actually started big play in nulling jumpers publicly to start with. I haven’t tried it I guess you just have to short one end make them. I have not had the need to do anything else. Not broke don’t fix it
@@DonkeyStomperProducts The Rig Experts manual on the 55 says you have to short one end of a half wave. I've seen people also use a tee and a dummy load on the MFJ for a half wave.
Great info, appreciate the video! Got 100ft of RG 213 from my Buddy, doing the math around 96ft should be nulled on ch20, put an end on it, nulled for channel 40, called it good. It will very, put a meter and nulled jumper in line and came down some.hopefully with driver and amp it will be spot on. Thanks for sharing!
Np, Thanks for everything, watching and the support.
I called and remember talking to you on the phone about these tuned jumpers along time ago. And then I started trying it on my own. I think I made more of around the 6' length and one that was around 12' in length. My question is what do most people run into their own setups? Is it the 6' or 12'? Or will it hurt if it was a mix the lengths at all?
We always do it with analyzer what ever length zeros out.@@shawndavis7067
With a properly installed radio/antenna system, the radio is 50 ohms, the cables are 50 ohms, the amp is 50 ohms, the meter is 50 ohms, and the antenna feed-point is 50 ohms, the length of the cable need only equal the distance to connect one device to the next. No more no less. When the device impedance at both ends of the 50 ohm cable are matched to the cable impedance, the "cable length don't enter into it" except for maybe minor loss in the cable..... Since there is no standing wave or reflection with a matched system, the impedance along the cable stays the same (50 +j0), except for minor cable loss.
Now if the antenna is mis-tuned, then you can try to adjust the cable length to make the radio "see" 50 ohms into the antenna/feedline system.. But, you be using up a lot of connectors and solder, measuring and cutting. Better to adjust the antenna length or position for best match (low swr). This video showed the extreme impedance mismatch of open or "infinite" impedance at 28 Mhz. When you put this "finely tuned 1/4 wavelength cable" in line to your unknown system impedance, cutting the length without knowing the actual system impedance, is futile, and unless your antenna has parted from the feed-line, the antenna feed point impedance is NOT infinite (open), it is some unknown value between open and short.
A 1/4 wavelength trimmed coax, as shown here, is commonly used for "stubs" to filter unwanted frequencies, or while installed in a feedline system can be trimmed for matching. It has to be installed in the antenna system while trimming to be effective.
Thanks for watching. How ever you want break it down is up to you. It works way better for what I do. I'm sharing it proven over over on my gear. Thanks!
Dang buddy you make that look easy hope to get one of them tools cool thanks for this video Big Guy 👍 as always thank you for what you do for us and the hobby!!!!!!
No problem 👍
Thanks for the info. Good Monday to you.
Same to you!
Thanks for your time and info buddy. That’s very helpful.
Any time!
Awesome video Beavis,thanks man,I love learning!
Np! Thanks for Watching.
Nice coax tool got to get one of those
Yes you do
I’ve learned how to do it , I’m slow at it but I’ve gotten very efficient with PL-259’s and .400 size coax
But I don’t know if I’ll ever learn or have the patience to deal with the bigger coax and connectors like you done for me on that Heliax
73 ,, and great info !
You can do it just watch the metal inside it cut you up.
@@DonkeyStomperProducts
You ain’t lying Chad,the corrugated shield in any sort of hard line,even super flex will cut the shit out of you.
@@SkipShooter yup
Ya, that is different than I normally do it. Looks like a better way. I always had to fight getting the ground soldered and never thought of pre soldering the ground. Do you do it in 3ft increments.
We always do it with analyzer what ever length zeros out.
Good video my rig expert is on its way I’m afraid of what I’ll find on my a99 and coax run. Curious, do you have some recommendations for flexible coax to use on jumpers? Most I’ll be running through them for now is about 1kw peak but with all the jumpers I gotta make up the rg400 is out of budget after that analyzer purchase.
I use 213 or RG 393. I hear RG400 is a good option for medium powered jumpers.
Great video! Thanks Chad!
Glad you liked it!
Always appreciate the info.
What is the shortest 213 jumper that you can null? For 27.185.
Thanks for stopping by!
@@DonkeyStomperProducts
Appreciate it..
I just happened apon your live feed erlier.
Thanks for being so available.
Why are you doing this? Are you making a matching stub to phase antennas?
Because it works....More less hiding the coax in line. Anything you put in line changes SWR, OHM, Impedance were its another amp meter switch box etc. If your big ham op with a HF rig with built in ant tuner it can take care of it for you. Thanks
So, what did the overall length of the jumper end up being tuned for channel 28?
I did not measure it exact, Start at 6'4 first one cut it down with a analyzer. Remember different brands, types of coax will all be different. Even coax ends.
What is a jumper and what is it used for or on because I dont have a clue or missing something.
Hook up watt meters amps any kind of equipment to your station
What is part number of coax stripper tool ?
www.dxengineering.com/parts/dxe-ut-8213
@@DonkeyStomperProducts thx aa2bd
261 Canyon Hopper southeast Utah waving a hand, I’ve got a question for you on nulling coax, does it matter weather you short the end out to get your R-x down where you want it vs just doing it open? I’ve done it both ways and get great results so I’m assuming it is good
yes you can short it just doing it in a different wave length. I have great luck the way I show it. Thanks
Ok awesome Thank you I appreciate you taking the time to answer my question, I appreciate it 😎
👍👍👍👍👍@@mikehannahs
That's a quarter wave jumper. Show how you use the MFJ making a half wave jumper.
I haven’t been making them any other way. This works for me not gonna mess it up..
I actually started big play in nulling jumpers publicly to start with. I haven’t tried it I guess you just have to short one end make them. I have not had the need to do anything else. Not broke don’t fix it
@@DonkeyStomperProducts The Rig Experts manual on the 55 says you have to short one end of a half wave. I've seen people also use a tee and a dummy load on the MFJ for a half wave.
I though you had short it. Just never wanted to change mine work so well.@@Metalhead396