Tiny NoodleTenna for HF Limited Spaces
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- Опубліковано 15 січ 2023
- This is a BRAND NEW type of HF antenna for those with extremely limited space to setup a conventional antenna. It is derived from the Slinky Antenna but with a few upgrades. It is less than 1/5th the length of a normal dipole, yet performs similarly. No ground, radials, counterpoise, tuner or BalUn required. Just a coax feedline with a Mix 31 common-mode ferrite choke at the antenna end. It uses widely available ordinary parts which cost less than $25. It is easily scalable for other HF bands and can be used in vertical or horizontal mounting, including with other NoodleTennas on the same mast, acting like a fan dipole. On 10m the bandwidth is about 600 KHz below 1.5 and about 1 MHz below 2.0 I've made many contacts with it, getting good signal reports. You can build one in about 2-3 hours.
MATERIALS: (scale the lengths for other HF bands)
3" diameter (large type) 50" long pool noodle
40" of 3/4" schedule 1120 (thin-wall) PVC pipe
3/4" PVC "T"
3/4" PVC elbow
3/4" flat-top plug (smooth)
2" long 3/4" PVC stub ("T" to elbow)
6" long 3/4" PVC stub (for mast)
2' of coax (RG-8X, LMR240 or RFC240) with female BNC or UHF connector
www.ebay.com/itm/133481890997...
28' of 18 gauge stranded hookup wire
4 10" cable ties (2 at center, 2 at ends, 1 at bottom of the noodle)
TOOLS:
1/8" drill bit for center hole in PVC pipe
1/2" drill bit for BNC connector threads thru flat cap
7/8" wood bit (spade blade type) for hollowing out inside of cap
OPTIONS:
6 Snap-on ferrite beads (Mix 31) for common mode suppression on antenna end of coax
www.jpmsupply.com/Snap-It-Cor...
3/4-5 TPI tap for threading 1/2" x 3/8" PVC reducer to fit painter poles
www.ebay.com/itm/254642664421
Telescopic camlock mast (up to 31 feet high)
docadone.com/products/docapol...
Tripod that fits up to 2" diameter mast
www.ebay.com/itm/363482179344
Guy wire ring, tie-downs, adjusters & ground spikes
www.ebay.com/itm/114891585326
ASSEMBLY:
1) Mark the pool noodle every 1 inch with a Sharpie
2) Cut pool noodle into 2 sections, each 20" long
3) Drill 1/8" diameter hole at center of PVC pipe thru one side only
4) Slide both noodle sections onto PVC pipe leaving a 1" gap at hole
5) Divide the hookup wire into 2 pieces, each one 14' long
6) Thread both wires into hole and pull both to one end of PVC pipe
7) Strip coax back 1", solder each to coax and cover core and braid each with heat shrink
8) Drill PVC plug to fit coax connector (1/2" thru hole and 7/8" counterbore inside of cap to make thru hole wall about 1/8" thick)
9) Thread coax connector into one end of PVC "T" and out the side port
10) Insert 6" PVC stub to other end of PVC "T"
11) Attach 2" stub to elbow
12) Thread coax connector thru stub/elbow combination and attach to PVC "T" side port
13) Insert connector from inside of PVC plug and secure with its ring nut to flat outside
14) Insert PVC cap with connector onto PVC elbow facing away from noodle
15) Pull wires so that coax pulls all the PVC fittings can be joined together snugly
16) Slide both noodle sections together at hole in pipe
17) Pull wires perpendicular to noodle in opposite directions
18) Bring the up each wire onto the inner end of each noodle
19) Attach cable tie to each at inner ends of noodles to hold wire in place while winding helix
20) Wind one noodle with wire so that helix has even twist with 1" spacing between each turn
21) Wind other noodle with helix in the SAME WINDING DIRECTION as the other noodle
22) Tie off each wire at the outer ends of the noodles with cable ties
23) Adjust cable ties for for wire support at each end of each noodle with snugness
24) Trim off excess tails of cable ties
25) Connect to rig with good quality coax with at least 6 snap-on mix 43 ferrites at BNC-M end
26) Attach to mast at the 6" PVC stub
27) Raise the antenna and test with antenna analyzer
28) Trim both wires to the EXACT SAME # of turns until in resonance at the desired center frequency
Its nice ti see that there are still hams out there that build their own antenna's rather than just buy some piece of junk. The Problem with most new hams is they have not had the privilege of an Elmer to teach them along the way. So they just buy what they need instead of experimenting and gaining knowledge and having the fun of seeing the fruits of their labors on the air. I have had that thrill for over 50 yrs and still get excited to build something and watch it work and see my creation create qso's good show. RudI!
Great video and very cool design. As a new ham just over a year ago I've been exploring different antennas to build. Definitely on a budget so it's cheaper than buying new, tho I love building and then having the joy of using it makes it so much better. Thanks for the video, looking forward to more. 73's
This is brilliant. I live in a condo and im getting my licence. Figuring out an antenna was giving me a real problem.
Wow cool idea. Opens so many possibilities. 46 years a ham and you fed my brain thanks you are a rock star.
I like pool noodles. I use one for the form of the loading coil on my 15-40 meter portable vertical. It costs almost nothing, (compared to the ridiculously-priced commercial coils,) and allows me to easily adjust the tap on the coil. And the form has essentially no loss or added weight.
Beautiful job Rudi! Thanks for sharing.
Very ingenious design. Well done!
Terrific idea, and a clear well-presented video as well. I’ve subscribed and look forward to watching your future content. Well done!!
I'm sitting here with a big, stupid grin on my face. I am going to have to try this! Thanks for the video! : )
Hi Rudi, great video with lots of detail, very cool idea, i am a fairly new HAM and this is very inspiring!
Wow glad I found your video Rudi, I've been kicking around the idea of get my general, but I live in an HOA and have no space for large antennas, and needed something I can put up and down, and takes no space up. Your design would be perfect for me. You're the man.
Good for you! I’m absolutely chuffed and encouraged to have a go. I part laying around gathering dust, and so also suffering from terrible arthritis, I dare to call this approach therapeutic! 😅 Thanks for your kind easy going instruction too!
Magnificent ! Thanks for posting this !
Nice construction👍
New fun project. Thank you for this video.
I'm going to be traveling for training at a new job and was dreading not having my radio in the motels. My first week in the hotel I'm going to try to build one of these. Thanks!
This looks cool, I may have to try it Thank You
Thanks Rudy for this inspiring project. I built it and tested it out. Made a fantastic QSO from Gibraltar to USA through this antenna. What I have found it to be too deaf, in other words it captures a lot of interference and over loads my icom 7300. The SWR was perfect on 40, 20, 15, and 10. In order to hear a qso I had to have them strong, say 5/7 to hear them at about 5/4, 5/6. 73's and welcome any feedback.
Reminds me of the TV set-top curly dipoles of the 1950s/60s.
That's cool, looks like FUN and easy.😀😀😀
A great idea. Thanks for the video.
This kind of reminds me of "The Heli-Rope Antenna" in the June 1971 edition of QST. Instead of a pool noodle, they use a much smaller form... rope.
Pool noodles are cheap, light, and have a nice large diameter to get lots of wire length in a compact form factor.
Thanks for the great video! Subscribed.
Nice work, Rudi!
Not a bad looking antenna, too.
I'm looking for perhaps a magnetic mount for an indoor base in conjunction with the Baofeng UV5r radio.
So many ideas and many of these seem to work just fine.
Enjoyed watching, thanksv& take care...
Great idea!
very cool! Genius my friend. Thank you!
Very interesting. I have not seen anything like it before.🍻
Brilliant 😍
Fantastic!
Really well explained. Can you draw and post. It would be most useful. Great Job. And very detail explained.
This sounds really cool to try .i like 40m . So this around 13ft . I will go with 3in pvc
I like it . Thanks
Hi Rudi!! I'm extremely excited to find your video! I've been considering using a set of pool noodles to create a helically wound cubical quad antenna. It would have some wind loading because of the noodles but (going out on a limb here) if we can reduce, for example, a 20m quad's radiating element from ~5m/side to ~1m/side (using your quote of a dipole 1/5 the normal size), that's a _HUGE_ reduction. That would even put a 40m quad within a reasonable size. I realize there's some inductance with a purely helical design but I think it's something that might be worth pursing. The nice thing about quads, from what I've read, is unlike yagis, they don't need to be 1/2 wavelength above ground.
I'd really like to know what you think of a purely helical wound quad, using pool noodles (and some sort of frame to support it, of course)? I'll check your other videos too! You definitely have a new fan here. (Due to uncontrollable circumstances, we lost our home a few years ago, with little notice and had to settle for a HOA condo so, antennas choices are slim.) Very best 73's!! Tnx de WB3CFN ...dit dit
The main idea here was a stealthier and more portable antenna for POTA and HOTA (HOA's-On-The-Air). Kind of like the next step from a hamstick dipole. There's LOTS of different directions to take this. I like the multi-band parallel dipole approach with 3 NoodleTennas on mast. The 10m vertical at the top, and two horizontal dipoles below that (15m and 20m). Then feed them in parallel just like a fan dipole. These are already are right angles to each other for good EM separation. Remember to use a good common-mode choke like 6-8 snap-on Mix 31 ferrites at the feed point with a tight fit to the coax.
I think that's pushing the concept a bit. BUT TRY IT.
Thanks 👍
thanks my friend terrific job 73 from kb2uew
Looks a nice job but I would have liked to see it in action.
I concur, I was waiting for him to go ahead and transmit and receive
Hey Rudy, great video. Is this QRP only or will it take 100W?
Man, I think I found my next project!
Great idea. How well does it preform
How would this work as an attic antenna in a 1-story house?
Also, if making multiple noodles for different bands (like a fan dipole), would it matter orientation and which was higher than the others?
Thanks for putting the instructions in the description! This is great!!!
You can definitely connect them at the center and feed them off a single coax like a fan dipole. Cluster them as a 3D Cross.
thank you for the video Allan G6TMO
Great idea! FYI, extendable versions of the threaded pole are available at Harbor Freight. They're about 3ft long collapsed, but extend to 9 ft long when extended. They're designed to extend paint rollers, but would make an excellent mast for your antenna.
Interesting concept and construction. Thanks ! Subscribed to your channel ....73,WG7D
Crusing youtube and found your channel. Love the idea of the antenna. One question how do you figure out the number of turns per band?
Just use 18 turns on a 70mm diameter noodle on each end for 10m version and scale linearly from there. 20m would simply be 36 turns at each end. Fold-back excess (DON'T CUT) to tune it to a higher resonant frequency. If your SWR never gets down to about 1.5, then you have a mis-match in wire lengths between the 2 ends.
If you start with my length or windings for 10m, just scale for the band. EG-20m would be 80 turns total.
So......does this mean you can work DX while lounging in your pool ?
Something to think about !
Any chance to configure these into a multi band beam ?
And if they fall over, what are they going to hurt....?
Genius !
Congratulations !
Hi Rudy, just seen this and suits me perfectly. I have a question. If it’s being used as a vertical antenna could you build it to have all 7 bandwidths on on length?
I understand that if this was done you’d have 7 lengths of coax hanging down but putting that through two 4:1 selector switches and then a 2:1 switch do you think it would work. ?
Thanks.
If you're implying a multi-band version, see my comments here for a tri-bander version (20/15/10) all parallel fed off one coax.
Best way is a "3D cross" of 20m, on the X axis, 15m on the Y axis and 10m on the Z axis
That's a cool idea. Thank you very much for the video. Out of curiosity, what wire gauge did you use? 73.
Thanks Rudy! I built the 20 meter helical wound pool noodle dipole antenna. Attic installed application approx 30 from ground elevation using 14 awg steel fence wire, w/coax RF choke. Logged in to share a performance testimony. 20 meter/100watt/SWR 1:1, horizontally mounted, space weather propagation conditions average - contact a few days ago, upstate New York to Capetown, South Africa. The noodle gets the job done.😀 Question: have you determined if the antenna has a circular wave pattern and would the signal direction be perpendicular to the dipole or generate off the ends?
Good to hear you had that kind of performance. Any more updates for like 40m yet or are you still playing on 20m. Im asking because I think I am about to build one for 20 and 40m
@@k7ilo_Las_Vegas for now just the 20M. The set up is working great. No 40M as of yet but I do see one in the future. It's actually a pretty fun antenna to construct. I found using painters tape to hold the windings in place every couple of turns helps hold things in place as you wind the wire. Plenty of DX contacts on the cheap. Good luck with your builds.
A helical antenna this size won't radiate very much off the ends at HF. The circumference has to be close to the wavelength for a helical to fire that way. For 10m, that means the antenna has to be 3m in diameter!
interesting miniature antenna design ! what is the 2:1 VSWR bandwidth for the 10m version ?
I had an elmer doing this on pvc pipe in 1980. He just liked to tinker.
does it matter if you use mix43 or mix31 ferrite for this?
What would be your best guess for the 2 meter and 70cm bands as far as length, spacing, etc? Great video --- easy to watch visually, great quality audio, no rambling, and straight to the point. Keep up the good work. Look forward to other videos you've made or will produce in the future.
very good idea, and the antenna is very light. thanks for video. AG6JU
Hello Rudy, would there be any advantages of doing the pool noodle on a schedule 20 say 6in diameter pipe instead of the smaller diameter pool noodles? Im thinking larger diameter might allow for a little larger antenna and maybe better performance? What are your thoughts? Over the winter its hard to locate pool noodles in my local stores. kk7aim
Wonder if you could build a reflector and director? Mini noodle beam!
That would be interesting but somewhat bulky for POTA and HOTA (HOAs-On-The-Air). I'm working on a trapped multi-band version (20m/15m/10m) instead.
Could you make a beam antenna using elements like this?
You should make a “linked” dipole pool noodle Dipole!
Could do. Or even a trapped longer version for 20/15/10. GO FOR IT!
how important is the coil spacing? could they be made tighter for 80m?
Have you ever attempted to use one of these 20m noodles with a 49:1 transformer, effectively making it an endfed half wave on 40 m. So instead of having the break in the middle just feed it at one end and wrap the wire all the way to the other end
Thought about that. For 40m you'd need a noodle that was 4X the length of the 10m of course. That gets pretty unwieldy. With a 20m version I split the antenna into 2 noodles and stick the PVC tubes together at a cross and connect my coax thru a BNC to a pair of spade-type connector pairs for quick assembly/disassembly. That's big enough for me.
Never tried that, but you'd need a HUGELY long noodle! TRY IT!
No radials required for the 20 M version? I like the design I would make an array 10-40
See comments for a 3-bander version.
How did you choose the 1 inch coil spacing? What is it's significance? What happens if it were changed?
I haven't taken the time to try different winding spacings. I went by my experience with Slinky antennas (MUCH more ohmic losses). Remember that the short you go, the less sensitive the antenna is on receive. I complement my NoodleTenna with a dedicated long-wire on my SDR receiver with a T/R switch into the rig.
You just need enough wraps to give you the electrical length it wants for resonance. One inch was convenient, that's all, nothing magic.
Can one make a nonresonant EndFed Noodle with 9:1 UnUn plus choke at the feedpoint? Would need a counterpoise wire but it might be more multiband compared to a dipole design?
Yes, I've built one with 2X5''x4" OD noodles, 12 ga wire, a mess of ground radials and an LDG RT-100 remote tuner at the base. Loads up and seems to get out fine.
What gauge wire? How much power will it handle?
Thinking 2 Ele mini beam.
Thank you.
I am going to try and build one of these. Can someone clarify the winding directions for the two opposing half elements. Does winding in one direction mean winding the entire antenna and then splitting the conductor in half. Alternatively, does in mean winding one half from the end to the center, turning the noodle 180 degrees and then winding in the same direction. In the latter case the winding vectors point in opposite directions.
Winding "handedness" on either side doesn't seem to affect performance.
I'e tried both ways, same direction AND opposing directions. Doesn't seem to make much difference.
@@antennawhisperer-k7raw151 I have mine built. I have to trim it and test it. I will let you know how it turns out. The build itself was pretty straight forward and simple. I would love to see some plans for helically wound Moxon for the upper HF bands.
The 20 m version...If you take the t in the middle bring the co ax out a different hole you can use the hole to put it up in the air on a riser like the painters pole. Hmmmm
Hi- Maybe I missed something. Why wouldn't the wire be almost 35 feet cut in half for a full wave at maybe 28.500 mhz. Where did 28 feet cut in half come from? I guess you can tell I'm pretty new at this. Thanks.
THe relatively tight turns of the helix delivers a LOT of inductance and shortens the effective electrical length anyway. So you need a lot more wire length to get back to resonance than a standard straight dipole.
@@antennawhisperer-k7raw151 Thank you
How long is that pvc pipe?
Hello Rudy, can you cover a bit on how you derived the dimensions of the wire helical coil of 80 turns for 20m? If you are using a 3" diameter, that 9" of wire per turn for 80 turns (I am assuming 40 per leg) or 360" on each side. Where as a typical dipole leg for 20m is approximately 16.64 ' or 33.27' for the whole antenna. Unless you are saying that the each leg is almost a half wavelength for each band, thus the approximately 30' for each leg for a 20m dipole. I hope this make a bit of sense, as I would like to construct one this weekend and give it a go. -Jason WV3V
Hi Jason. The 3" noodles are actually 70mm diameter. That gives about 8.6" per turn. For 10m that's about 18 turns with 1" EVEN spacing PER SIDE which will get you in the ballpark. Then trim BOTH ends EXACTLY THE SAME FRACTION OF A TURN (eg-1" at a time) until you get the lowest SWR (should be about 1.5). A 20m dipole will be about 2X the # of turns, and proportional for all the other bands.
Turned out to be trial-and-error. But the 10m formula scales to other bands.
how much dB loss does that poolnoodleantenna has compared to a straight wire ?
Hard to say. I'd estimate that there is some RF losses in the coil structure itself. I have not tested it against a known antenna performance on RBN.
what is the power rating for the 10-meter antenna? it sounds interesting.
If you use 18 gauge or heavier you can confidently run 100W.
If you use 12-14ga wire you're good for 100W+
Thanks for sharing, great idea .
I hope the next video is showing this ant on the air.
73 zl3xdj
Any chance of measured plans on PDF?
I am interested in compact antennas. Could a 10m helically wound Yagi or Moxon with gain and irectivity be built?
interesting concept a wire wound moxon . wind wire around a form moxon shape to reduce the size and see if you can get the good swr and moxon characteristics . I guess use a wood U shape form to wind wire on, then couple another end to it with spacing separation for best SWR- then perm fix. I would use 1/2 scale to start with 1 extra turn to see if it works.
Second thought use the noodles to form the moxon frame. then an unwound noodle section as the spacer between reflectors. The noodles would be super light. Noodles maybe for a mag loop idea too.
Google - W7XA 40m mini moxon beam antenna
All cool ideas. There are LOTS of directions to take the basic idea. GO FOR IT AND SHARE IT WITH THE GROUP.
An A-B comparison would have been great with another antenna.
Hi sorry to bother you am from the east coast of the U K M6 PHS ham call
I live in a flat with ni outside space can your pool noodle antenna work with an end fed wire
I have a wire that goes from 80 to 10 meters with my ATU if it can be done will you be so kind as to help me by doing a diagram please thank you very much
M6 PHS or better known as phil .
Pure genius - this is the kind of thinking that you never see from the iPhone generation . Just sayin. 🙂
Can you get a match to your radio...yup. is it going to be efficient...not so much
on the one hand, I absolutely love this project combined with its potential. However, the list of parts does leave something to be desired. I went to Lowes and Home Depot and could not locate the parts. Of course, I found the pvc 1120 tube, no problem. I found the pfc (3/4") T and the 90-degree elbow, also no problem.
But the 3/4" flat-top plug (smooth) 2" long could not be found.
The 3/4" pvc stub (T to elbow) 6" long could not be found.
If a skew-number were available, then locating the parts would be easier. I think the problem is that everybody has their own terminology for the pvc parts. I have to say, I am stumped. (Certainly, the customer service people at the stores are stumped.)
Ten meters antennas already are small. How about making one for 40 or 20 meters?
Well, if you consider 17 feet for a 10m antenna small, then that makes the NoodleTenna TINY in comparison. You can easily make a NoodleTenna for other bands such as 15m or 20, etc. Just make the number of turns on each leg proportional to the 10m version. For example, a 15m version would be about 30 turns per leg versus the 20 turns for 10m.
He shows a 20m antenna at the end.
Sorry but a coiled radiator cannot be as efficient as a full sized radiator.
better than nothing in an apartment
Soldered no silent L
Do not expect to be very successful with this antena. This is really not worth the effort. A magnet mounted Hustler mobile antenna will be more efficient, plus it will be much more stronger. This antenna is not worth the effort. Hellically wound dummy load is what best describes this construction project. Will it work, yes, only because QRP works. 73, Morgan NJ8M
You Sir are a genius 🙏 DE KC0-FRW
Thanks. N0QFT