I'm just gathering the material to build a doublet in inverted vee form. Each leg will be around 85-90 foot in length, and will use 14-guage black insulated starnded wire from Amazon, and 450 ohm ladder line. My tuner is an LDG-AT1000ProII tuner so hopefully it will tune OK, along with a 1:1 balun (a 4:1 balun will be on standby). I was thinking about a ZS6BKW (which is just a doublet with resonant wire lengths)...but the doublet can just be any non-resonant lengths, so I went with that.
I would not be quick to say a doublet can just be any non-resonant length It is still a dipole just fed balanced as a dipole should be . It a proper dipole All that is proper with all dipoles still proper here Start with wavelengths Not just random lengths of wire This sort of sounds past tense A balanced dipole is from the beginning It was not till ww2 when unbalanced coax become popular The dipole who was the balanced dipole predates that
Thanks Steve, I'm still wrapping my head around use cases for different baluns and you helped fill in the gaps. Also, thanks for using affordable products to test with - love LDG products. 73, K7KS
The easiest way is to measure the impedance presented from the antenna, then do some maths to figure out what transformation you need to go from that measured impedance to 50ohms for your radio. 4:1 is 200:50, 9:1 450:50, and 49:1 is 2450:50 for popular choices... then there are 1:1 which are used to remove RFI from your coax and keep your radio happy in a different way. -- one thing I should have done was measure the impedance first... but what's the fun in that.
After different experiments, also with a IC-7100, I found that using a tuner that has provision for the the feed line to be attached directly gives me the best results. My MFJ-993B IntelliTuner with a 144 foot doublet tunes 6M to 160M. Though on 160M using SSB it is marginal. It is a rock solid regional comm setup on 80M though. In digital mode it is a great antenna. In general, in my situations, I have not found baluns or ununs useful. Obviously other people's results are different. Like you I tried a number of different chokes and balun/unun ratios. As I have recently discovered there is great promise in using twin coax as a twin lead feed line. That is the direction my antenna experiments is going in this year.
Your comparison testing confirms what several "antenna gurus" of late are saying: that the 1:1 current balun is preferred over the traditional 4:1 balun to feed the doublet, because it results in less loss in the tuner, that the 4:1 balun can actually present a hard-to-match extremely low impedance to the tuner under some conditions and bands
While you can connect a tuner to ladder line, it's not balanced as one lead is ground, and then it's not technically a doublet. That requires a balun, and the tuner and balun should be connected directly to the ladder line. Meaning an external tuner and not in the radio. I use a 9:1 to match the 450 ohm ladder line. I think your RFI is from tuner and balun on opposite sides of the coax. Not optimal.
Steve, no criticism intended. Ham radio is really just one big experiment, and this short video really got me thinking and running the scenarios in my head. Excellent video.
That's what I meant. Coax to ladder line means one leg of the ladder is grounded which either grounds one ladder leg or turns coax shield into antenna. Didya think a 2 minute video meant this much work? 😉
You most surely could build a true (not talking about the famous uggies) 4:1 Balun with coax but would be single banded back in the day you would see the on beams with a folded dipole driven element. Since it required a 1/2 wave coax stub only good for one band
Steve Unun is not for a balance feed line Balun = balance to unbalanced (or vice versa) unun = unbalanced to unbalanced . So since the feed line and antenna is balanced you should throw out that column....but it tune right well your tuner will tune a lightbulb too.
Most people assume that balun=transformer instead of "adapter". Even with that in mind, your tuner might have a built-in balun. An example is a 49:1 transformer, it transforms a 2450ohm antenna to 50ohm for your radio, if the Doublet is 5000ohm, the transformer would help get you closer to your tuners range and allow tuning. (102ohm). At the end of the day, I was having fun and wanted to share.
Balun is balanced, as in the twin lead to unbalanced, as in the coax. The ratio represents the impedance change as mentioned. They are separate things. My 9:1 is NOT a balun but an unun, like most of them I've seen. Same is true of the 49:1 that I've seen. Not sure of any performance difference between a 4:1 unun and a 4:1 balun for this application. Not sure I've seen that comparison. Nice videos!
A doublet is balanced - you can tell by the way it is fed - in this case, the doublet is fed with ladder line. I always remember that coax is unbalanced. In the case of this antenna setup, I couldn't use an UnUn because I'm not going from unbalanced-unbalanced.
The best balun would be a balanced transmatch That would be best You can tune a guitar You maybe can tuna fish There is just no way to tune a antenna All that can be done is to match No a balun will not and can not Tune a antenna
I do not understand why experiments. You just need to figure out once for what tasks matching transformers and cut-off chokes are used. Just understand. 73!
The 1:1 would stop any RFI from heading into the rig where you switch from ladder line to coax. That solves all kinds of problems - and might even help a bit with tuning too.
The "antenna gurus" of late all say the 1:1 current balun is preferred to feed a doublet over the traditional 4:1 because there is less loss in the tuner
No and those tiny ldg ferrite suck. Tried on mine and even 100w would get them so hot the plastic case melted off junk. Bob @BalunDesigns is the only person to buy a balun. And a 3:1 max vswr on any balun. 😂
@@temporarilyoffline made hige mistake buying a palomar box and opened to see tiny cores and orange stay foam and tiny 18g wire. Tore that out of the enclosure and talked to Bob at Balun Designs and he gave a short explanation as to why when using 811h it’s very important to have a balanced feeder and 1/2w length on a hw doublet. Sadly I chose 130’ of feeder and that puts high impedance on the back of the tuner on 80m so high it gets cores smokin HoT I ve seen nylon balance stud insulator melt from RF & a blue flash as the studs shorted to tuner chassis. Porcelain or ceramic ☺️provides better resistance 😉
I use a 4:1 current balun with doublets. I also use a remote tuner (the LDG). My doublets tune 80-10 without a problem. The length of the balanced line can affect tuning. Tom W8JI has a good discussion of baluns and doublets in the DX Eng. info: Baluns: Choosing the Correct Balun. 22 pages of good advice.
@@temporarilyoffline that’s hilarious. I had a moment like that recently. I just moved from an apartment to a mobile home of my own and put up my home made end fed half wave. The trees on my lot are 70 feet tall so put it up entirely vertical… why not. It’s FREAKING AWESOME.
I'm just gathering the material to build a doublet in inverted vee form. Each leg will be around 85-90 foot in length, and will use 14-guage black insulated starnded wire from Amazon, and 450 ohm ladder line. My tuner is an LDG-AT1000ProII tuner so hopefully it will tune OK, along with a 1:1 balun (a 4:1 balun will be on standby). I was thinking about a ZS6BKW (which is just a doublet with resonant wire lengths)...but the doublet can just be any non-resonant lengths, so I went with that.
Doublet are awesome!
I would not be quick to say a doublet can just be any non-resonant length
It is still a dipole just fed balanced as a dipole should be .
It a proper dipole
All that is proper with all dipoles still proper here
Start with wavelengths
Not just random lengths of wire
This sort of sounds past tense
A balanced dipole is from the beginning
It was not till ww2 when unbalanced coax become popular
The dipole who was the balanced dipole predates that
Thanks Steve, I'm still wrapping my head around use cases for different baluns and you helped fill in the gaps. Also, thanks for using affordable products to test with - love LDG products. 73, K7KS
The easiest way is to measure the impedance presented from the antenna, then do some maths to figure out what transformation you need to go from that measured impedance to 50ohms for your radio. 4:1 is 200:50, 9:1 450:50, and 49:1 is 2450:50 for popular choices... then there are 1:1 which are used to remove RFI from your coax and keep your radio happy in a different way. -- one thing I should have done was measure the impedance first... but what's the fun in that.
After different experiments, also with a IC-7100, I found that using a tuner that has provision for the the feed line to be attached directly gives me the best results. My MFJ-993B IntelliTuner with a 144 foot doublet tunes 6M to 160M. Though on 160M using SSB it is marginal. It is a rock solid regional comm setup on 80M though. In digital mode it is a great antenna. In general, in my situations, I have not found baluns or ununs useful. Obviously other people's results are different. Like you I tried a number of different chokes and balun/unun ratios. As I have recently discovered there is great promise in using twin coax as a twin lead feed line. That is the direction my antenna experiments is going in this year.
That 993b has a built in 4:1 balun... that's the same reason why I don't normally run with a balun when using a tuner.
Your comparison testing confirms what several "antenna gurus" of late are saying: that the 1:1 current balun is preferred over the traditional 4:1 balun to feed the doublet, because it results in less loss in the tuner, that the 4:1 balun can actually present a hard-to-match extremely low impedance to the tuner under some conditions and bands
It was a fun experiment. These things need to be done as tech changes to challenge the old-think in the presence of new-stuff.
Feed the doublet with ladder line and a 4:1 balun! I work all bands and tune with internal IC7300 for years.
Sweet! That's just what I did
News from friends in WI leads me to believe you're not going to be testing antennas outside today.
Or all next week either! Low single digits inbound!
Cool experiment!
Thanks, it was fun!
While you can connect a tuner to ladder line, it's not balanced as one lead is ground, and then it's not technically a doublet. That requires a balun, and the tuner and balun should be connected directly to the ladder line. Meaning an external tuner and not in the radio. I use a 9:1 to match the 450 ohm ladder line. I think your RFI is from tuner and balun on opposite sides of the coax. Not optimal.
Exactly! It was a fun thing to play with and it connectd some dots in my head.
Steve, no criticism intended. Ham radio is really just one big experiment, and this short video really got me thinking and running the scenarios in my head. Excellent video.
@@ndoren I didn't take it as criticism, and I'm glad it got some gears turning! Thanks!
That's what I meant. Coax to ladder line means one leg of the ladder is grounded which either grounds one ladder leg or turns coax shield into antenna.
Didya think a 2 minute video meant this much work? 😉
You most surely could build a true (not talking about the famous uggies) 4:1 Balun with coax but would be single banded back in the day you would see the on beams with a folded dipole driven element. Since it required a 1/2 wave coax stub only good for one band
Steve
Unun is not for a balance feed line Balun = balance to unbalanced (or vice versa) unun = unbalanced to unbalanced .
So since the feed line and antenna is balanced you should throw out that column....but it tune right well your tuner will tune a lightbulb too.
You are correct. Its just there for comparison/info. Thanks for watching.
I'm confused. That's ok, happens often. Don't you always want a balun of some sort on a doublet? Assumes radio is coax out.
Most people assume that balun=transformer instead of "adapter". Even with that in mind, your tuner might have a built-in balun. An example is a 49:1 transformer, it transforms a 2450ohm antenna to 50ohm for your radio, if the Doublet is 5000ohm, the transformer would help get you closer to your tuners range and allow tuning. (102ohm). At the end of the day, I was having fun and wanted to share.
Balun is balanced, as in the twin lead to unbalanced, as in the coax. The ratio represents the impedance change as mentioned. They are separate things. My 9:1 is NOT a balun but an unun, like most of them I've seen. Same is true of the 49:1 that I've seen. Not sure of any performance difference between a 4:1 unun and a 4:1 balun for this application. Not sure I've seen that comparison. Nice videos!
I see one was a UNUN (9:1). Would a 1:1 UNUN perform better that the 1:1 BALUN? I do not know if the Doublet is balanced or Unbalanced.
A doublet is balanced - you can tell by the way it is fed - in this case, the doublet is fed with ladder line. I always remember that coax is unbalanced. In the case of this antenna setup, I couldn't use an UnUn because I'm not going from unbalanced-unbalanced.
Which of the many radios you own has the best internal tuner? It's not the 7100...
The Kenwood TS-570d has the best - able to find a match and complete a QSO on 160m tuning my DX Commander Classic
I think a better tuner could use any of those baluns and tune up ok, you are really trying to find the best band-aid for your radio
@@edbeckerich3737 I was just playing and sharing.
Why dont ya make a multi tap teansformer and use a selector switch and u should always use a CMC at the feedpoint
Good idea
But if your were just doing CW, there would be no RFI ?
There would still be RFI, you just might not notice it as much.
The best balun would be a balanced transmatch
That would be best
You can tune a guitar
You maybe can tuna fish
There is just no way to tune a antenna
All that can be done is to match
No a balun will not and can not Tune a antenna
You got that right, thanks for watching!
I do not understand why experiments. You just need to figure out once for what tasks matching transformers and cut-off chokes are used. Just understand. 73!
Yep
I don't know much but a 1:1 doesn't sound right on a doublet. Go figure.🤷♂️ :)
The 1:1 would stop any RFI from heading into the rig where you switch from ladder line to coax. That solves all kinds of problems - and might even help a bit with tuning too.
The "antenna gurus" of late all say the 1:1 current balun is preferred to feed a doublet over the traditional 4:1 because there is less loss in the tuner
No and those tiny ldg ferrite suck. Tried on mine and even 100w would get them so hot the plastic case melted off junk. Bob @BalunDesigns is the only person to buy a balun. And a 3:1 max vswr on any balun. 😂
💯 on Balun Designs. Nailed it.
Interesting, I haven't used them enough to run into that problem. Thanks for the heads up.
@@temporarilyoffline made hige mistake buying a palomar box and opened to see tiny cores and orange stay foam and tiny 18g wire. Tore that out of the enclosure and talked to Bob at Balun Designs and he gave a short explanation as to why when using 811h it’s very important to have a balanced feeder and 1/2w length on a hw doublet. Sadly I chose 130’ of feeder and that puts high impedance on the back of the tuner on 80m so high it gets cores smokin HoT I ve seen nylon balance stud insulator melt from RF & a blue flash as the studs shorted to tuner chassis. Porcelain or ceramic ☺️provides better resistance 😉
@@kevinkc3onohelijeepworld Living on the edge man!
I use a 4:1 current balun with doublets. I also use a remote tuner (the LDG). My doublets tune 80-10 without a problem. The length of the balanced line can affect tuning. Tom W8JI has a good discussion of baluns and doublets in the DX Eng. info: Baluns: Choosing the Correct Balun. 22 pages of good advice.
Geez… 100 meters is GINORMOUS…
It really is, I made a video on the build... basically I didn't want to cut/waste the wire... and I had the room. So why not?
@@temporarilyoffline that’s hilarious. I had a moment like that recently. I just moved from an apartment to a mobile home of my own and put up my home made end fed half wave. The trees on my lot are 70 feet tall so put it up entirely vertical… why not. It’s FREAKING AWESOME.
@@W3OY-RAY I don't know if I could toss a line that high!
@@temporarilyoffline a buddy helped… used a dog ball chucker thingie.
@@W3OY-RAY put a little "english" on it too I bet