MAKE A GREAT HF ANTENNA - EASY!
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- Опубликовано: 8 фев 2025
- The doublet is a very efficient and effective multi-band antenna. In this video I show just how easy it is to make one! This antenna covers 80-10m with a suitable antenna tuner. Ideally, use a tuner with a balanced input or put a suitable 1:1 balun between the antenna and an unbalanced tuner.
Questions? Ask them in the commenbts below.
Doublet antenna information www.electronic...
Items used:
heavy duty wire (50m) www.sotabeams....
open wire line spacers www.sotabeams....
centre insulator www.sotabeams....
stealth cord www.sotabeams....
tactical top insulators www.sotabeams....
cable ties
Knots:
figure of 8 on a bight gravitec.com/f...
bowline gravitec.com/f...
Oh man I nearly lost it during your John Cleese walk!! I will forever measure antennas with that technique.
Hi Richard..built many ants. Many radios blah blah..but still using this from when you first put it out...always works great..have added GOLD coated banana connectors into bnc×2 for some gangsta bling!!
Thanks Again!!!
Beautiful job on the feedline. I'm using 450 ohm ladder line at the moment.
Look forward to seeing the follow up video of this in operation! It goes to show that a good multiband antenna can be constructed for minimal cost.
Just waiting for a weekend when the weather is good enough to test it!
I made a wire doublet with your older style laser cut acrylic Center and spacers. That worked great. Also did a loop fed the same way, it worked really well too
Doublets are certainly useful!
Thanks for video Richard. Looking forward to next installment.
The humble doublet is perhaps often overlooked as an effective multiband antenna. I have used one QRP/P a few times. About 30' long, yet still managed some 80 thru 20m contacts with 5W and the antenna up just 5m.
One advantage over linked dipole is that you don't have to take it down to change band.
Thanks Steve. Just waiting fhe right time to test it!
Great video Richard. Can’t wait to see it working
Me too!
Thanks for the detailed instruction.
Glad it was helpful!
Bu-bu-bu-but, high SWR AND efficient! It must be that bird feed support thats doing the heavy lifting :D. Great work!
No. It’s the magic antenna dust that I used.
@@g3cwi_Radio_Adventures Ah, very nice, we call that Whip Grease in the states :D
Great video Richard and my antenna of choice with my balanced tuner for portable ops. Generally I use the ‘commercial’ 450 ladder which can be a bit ‘flappy’ in the wind (but easy to roll up and store....perhaps a bit easier than the open wire feed with spacers?) however it might be time for me to try some ‘home brew’ twin using your spacers to see how easy it is to deploy. I really recommend your ‘Sota-wire’ and WireWinders with fig8 technique. No more spaghetti! I did 266 SSB Qs over 3.5 hours in the 80/40 AFS contest yesterday with some DX to Indonesia and Afghanistan a bonus. My general config is 2 x 27m top wires (gives 2 x 5/8 on 40m and perhaps a tad of advantage) for 80-10 and I add 15m approx to each if I want to venture on 160 (a bit of a rarity for me unless contesting). Inv Vee config, centre at 10m which ideally could do with being higher...ends at 3-4m which I think is a min for inverted V usable on 80 (1/20 lambda). Keep up the informative content. Cheers, Nick M1DDD
Thanks Nick. I do stock some narrower insulators of the same type: www.sotabeams.co.uk/open-wire-line-spacers-short-pack-of-5/
Looking forward to seeing the details of the balun and its construction.
Antenna==>4:1 transformer==>Common mode choke==> antenna tuner
Good video, I'd like to see how well it works!
Very interesting and thanks for showing the build.
You are most welcome
Nice job Richard !! Very informative.
Thanks. I’m looking forward to trying it.
Another good one,Richard
Thanks
Handy for me. As I have an atu with both balanced & unbalanced inputs.
Thank you Richard. 73
G8TMH.
Sounds perfect.
Great video Richard 👍
Thanks!
Great video Richard. Would like to see a comparison with the Bandhopper (full size dipole).
Maybe I will do that. They will have very different radiation patterns on the higher bands.
Hmm, I see you used the 'European Death Knot' to tie the feeder wires together. In a more recent vid you were reluctant to use it, preferred a reef knot - bad decision! The EDK is perfect for this use case.
73 dre M0PTB
PeteS
So would you connect this to a 4:1 balun if your tuner had a coax output or would you use something else? Would you see high set readings but they don’t matter since the loss is so low?
Very nicely explained and done....
Thanks for watching!
Excellent video. Look forward to the next part.
Thanks - so do I!
I built this from your website a year or so ago.When choosing which one shall I pack this goes straight in radio pack others are 2nd choice! works great qrp with my 817 cheers 73
Good choice!
HI Richard. Great video. I watched it about a year ago. Back again as looking for something like this at my QTH. Normally I would have a mast in the garden but neighbours have mentioned it.
So just bought a atu waiting for it to arrive. Thinking I can get something like this in my attic. What's the shortest length of legs can I go? My attic is 8m long. My lowest band probably 40/20m to 10m
Tried a Z shape with efhw but not good on RX. Does it need a ballun on the end before a tuner?
Thanks in advance
Motters M7TRS 73 👍🏻
With 8m length you can do 17-10m.
@@g3cwi_Radio_Adventures thank you will have to see what I can do. If not will just keep it portable op's. 👍🏻😁
Liking the videos 😊👍 and keep the inspiration coming 👍
Thanks. I’m trying!
@@g3cwi_Radio_Adventures dont try to hard your doing well 👍😊
Another great video Richard.....for use at home what's the easiest way of getting the open wire feeder into the shack ?
forums.qrz.com/index.php?threads/bringing-homebrew-ladder-line-inside.452447/
What is the spacing between the two feed lines of this antenna?
Thanks. I would like to make one very soon.
10cm or so. Not critical
Excellent video, Richard!
73, Jo - DL1JRM
Thanks!
Thanks for sharing 👍
Thanks. It was fun to be out playing radio!
Great video, thanks I was going to ask can you show how you connect, you say 1:1 and then straight into a tuner, but I guess you will cover that on the next part, testing, I am eagerly awaiting.
Keep up the good work. Matt ‘M0ZKK’
Ignore above, it’s all covered in the attached links...
@@right360com I will be covering it in my video on testing the antenna too!
Thank you great video.
Thanks for that!
Very nice, Richard! I've always heard of the doublet, but didn't realize just how easy one is to construct. I have some window line at home that I want to try and make a dipole out of. It's on my list of QRP/field antenna projects. 😊
So 59 feet on either side of the center and 23 feet down to the tuner, is that correct?
Any idea when the live test in the field video will be made? I've just made this antenna (using Sotabeams parts) and would like to see how you run it portable.....
It rather depends on getting suitable weather for the video. It’s pretty gloomy here at the moment.
Richard, I noticed that you had in the video the antenna length is cut for 118 feet. How long in the length of the ladder line that you that you made??
Hi Dave; the antenna was made from 50m of wire so the feeder is the remainder.
Hi, Richards, thanks for your video. I would like to know which is better to use, with less loss and convenient and stable swr, in dipoles with balanced feeder line manufactured with Sotabeams open wire line spacers of 27.5, 50 or 120 mm long?. Why?nBest Regards
I would tend to use the longest ones myself.
Very well done video! I'm just getting back into the hobby so I have been watching a lot of antenna videos. LOL I'm also eager to see it in operation. Do you know what the impedance of the feed line is? VE1GF
The feedline is about 600 Ohms.
Nice and easy setup but it's so long! If the antenna isn't resonant anyway would it work with shorter legs (on 80m e.g.) as well?
Yes but as the length starts to drop below a halfwave, the efficiency starts to drop. So while it would work, it would not work as well.
What bands will it cover? And what is the connector you use to attach to fiberglass pole ? Super video again Richard. 73
80-10m. see video description for parts used. Thanks!
Thanks Richard,
Brill vid, can't wait for the next one ....
Thanks!
Exellent video, what sort of wattage will the antenna take?.
It’s mainly dependent on the power rating of the tuner.
I learned about doublet antennas from reading an old AM Phone forum. Those guys were running legal limit plus into doublets with old Johnson Matchbox KW models. I scaled down for my 100w station and haven't looked back! 73 de w8tam
Why is it all the wire antenna guns are in the UK? I've always like antenna building and noticed this over many years.
Interesting observation. Our planning laws coupled with a high population density make it hard for most of us to have towers and beams. We like our wire antennas!
@@g3cwi_Radio_Adventures Ah, yes the tower haters. We have then here in Australia too. All until there is a natural disaster and the radio people are our friends...... I'm currently studying for my license and the only part I dread is the tower battle.
To give a try for the first time, to receive, not transmitt, I had probably 36 feet of wire. My CB mobile antenna is base loaded and has a spring.
I pinched the wire in the spring and had the wire held horizontal 1-3 feet in the air.
I was receiving 20m and 40m rather well.
HERESY AGAINST DOCTRINE! 😁
I look forward to seeing it in the field. In a few months when all the snow has gone and the temperature is above zero, I shall have to try it. Thanks for the info on the knots. I failed knots in cubs. I like your open line spacers. VO1OK
Knowing a few knots it a very useful skill for our hobby.
in my 20ft x 22ft rear garden i have no chance of that going up. out portable a different story
Yes it’s a full size antenna!
@@g3cwi_Radio_Adventures now if i had a garden like yours the wife would be happy and so would to put a nice wire up in the garden. lol
but i will be trying something like this soon
Can’t beat a doublet
In many ways that’s true when it comes to simplicity, performance and flexibility.
Richard Newstead yep use one at home ... aside from efhw these are the best Multiband wire antenna option imho.
matches? feeling a bit poch arent we?
hahahaahah
Really good video - appreciated. I'm wondering whether connecting the open wire feeder to {say) 450 or 300ohm ladder line for the last couple of meters into my shack would be a good/bad idea? This is just for convenience as the OWF is a bit 'untidy' in the shack - and I can get 300 ohm feeder through my wall fairly easily. My thinking is that this would avoid a 1:1 balun (if I used coax) as the feeder still remains balanced although there is a bit of an impedance mismatch (60ohm to 300ohm). Can anybody comment - am I mad? Thanks Kevin M0XYM
I would give it a go. On the lower HF bands it will not make much difference.
Isn't that like a G5RV?
There are some similarities but the G5RV is really just a 20m antenna hat can be "fudged" to match on other bands.
@@g3cwi_Radio_Adventures So this one is better?
@@hcy0 Generally - yes.
The bit that confounds me is the "antenna tuner" fed with open wire feeder. You can't really take open wire feeder through a wall, so the tuner needs to be outside. That's the bit I need to see. I can make resonant dipoles fed with coax shoved through a hole in the wall, so what's the next step?
Paul Ryder you could attach the feeder to a 1:1 current Balun and then as short a run of coax as possible to the atu (it’s this run of coax that would present most loss)
I bring 450ohm balanced straight through a PVC passthrough to my inside shack, and have no problems with it. I've made many thousands of contacts on my portable doublet antenna and nearly as many on my doublet at home. 73 de w8tam
Although you can go for the balun option to "convert" from open wire to co-ax as Tim suggests. You can pass the open wire feeder through walls, window frames, eaves on roofs etc. provided you keep it away from metal (i.e. conductive objects). Assume that's why Thomas has the plastic baseboard.
Paul, I did exactly that. I drilled two small holes in my aluminum siding, inserted a small section of PVC tubing to prevent wear and tear on the wires, and ran the feedline right to the tuner balun, which sits next to my rig. Works great. Open wire ladder line can CROSS metal, just isn't good to run it ALONG SIDE metal.
Thank you ! Very nice and clear video !Waiting for test ! YO8XCM
Me too!!
For portable and low profile QRP use I highly recommend the NorCal design (www.norcalqrp.org/norcaldoublet.htm) that utilises 4 stranded computer ribbon cable to fabricate the radiating elements and feeder all from a 50 foot length of the cable (no joints and no feeder spreaders!). I use it at my home QTH and for CW I'm able to use up to 30W. It weathers well, and is easy to make.
Chris G3SQU
Thanks for sharing your views Chris. Please consider subscribing as I have lots of new content planned that you might find interesting.
All good. But this is a G5RV.
It’s not a g5rv.
🤔