How to Use a Coil Antenna for Portable HF Ham Radio

[@Rickazine]

I ended up buying the Wolf River right after watching this video. Today I set up and activated a Park here in KY, and Walt hunted me. That made my day. Thanks for the videos and thanks for actually being a hamtuber that uses his radio! 73 N4RIK

[@COASTALWAVESWIRES]

Congrats on the new coil and thanks so much for the kind words! 73, Walt

[@ronpetroski7203]

Started with the wolf river. But I also carry an efhw 40-10 with the 80 meter extension.

[@MikeN2MAK]

There are so many options for coil antennas now and that's a good thing! There's something for everyone, no matter what your budget or operating style.

[@COASTALWAVESWIRES]

Absolutely! 73 my friend!

[@dandypoint]

You talked about using a coil when the antenna is “short” or shorter than 1/4 wave. I am sure you know but lots of guys don’t seem to realize that you can resonate with L or C depending on the length. Shorter than 1/4 can be obviously be resonated with a coil. Longer than 1/4 but shorter than 1/2 wave you can resonate with capacitor. Longer than 1/2 but shorter than 3/4 can again be resonated with a coil. Longer than a 3/4 but shorter than one wave, resonate with a capacitor. Every time a wire goes through resonance (1/4,1/2,3/4,1 etc) the reactance flips from capacitive to inductive or vice versa. Sometimes using a series capacitor can be an easy way to resonate an antenna. I do that with my Inverted L that is a good bit longer than 1/4 wavelength.

[@Peter_S_]

I used to have a 19" rack mount antenna tuner which had an SWR meter and a trio of controls... There was one multi-position switch for selecting a coarse tuning coil, one multi-position switch for selecting taps on a fine tuning coil, and a big beautiful variable capacitor.

[@Peter_S_]

A friend had motor tuned coil antennas in his mobiles. They worked fantastic once tuned. Once you stopped on a frequency it was good to mark the point on the coil case with a pencil because the tuning was really narrow, but if you stopped on the line you were right on. With the tuning perfect and a 500 watt linear at high altitude, I was told the tips would emit a nice ball of corona.

[@COASTALWAVESWIRES]

hahaha I would have liked to see the corona ball! Thanks for commenting.

[@RonanCantwell]

Some great advice here, Walt. Thanks for putting this together. It's good to hear balanced and qualified opinions on this sort of kit.

[@COASTALWAVESWIRES]

Thanks so much my friend!

[@kagmich5796]

Hey just wanted to let you know that I really enjoy your videos. I just got my gen licence and your videos on antenna builds have been some of the best I've seen. You take all of the "word salad" speak on this subject away and get right to the results. Keep it up! I appreciate it.

[@COASTALWAVESWIRES]

Thank you so very much! 73, Walt

[@GordonHudson]

I only discovered loading coils two weeks ago. In 41 years I have never used one, other than in prebuilt mobile HF antennas. But the fan dipole in my attic (cut for 17m,12m and 10m) wouldn't tune on 10m and 12m so I decided to try and get 20m on it. I made two loading coils for the ends of the 10m section on carboard tubes and added 30cm of wire after the coil. There is an online calculator for working out the size and it was pretty accurate. I had to add a small amount of wire between the coil and the original dipole, but as its indoors there are no waterproofing issues. It really does work. Bandwidth is not too compromised and I worked from Scotland to Texas about ten minutes ago. I wanted it for CQWW this weekend!

[@COASTALWAVESWIRES]

That's a great idea! Thanks for sharing!

[@JohnSmith-xi2oq]

I had a buddipole, but ive been using a big kansas coil lately. Love it. Look em up.

[@adam-g7crq]

Hi Walt, I use a variety of different whips with the slide winder including the 17ft mfj telescopic whip in moderat breezy conditions as well with no real problems the coil hasn't snapped yet😁 , with the 17ft whip you can tune down to 60 meters, thanks for the video.

[@COASTALWAVESWIRES]

Thanks Adam and thanks for the info!

[@adam-g7crq]

​​@@COASTALWAVESWIRESjust a follow up Walt I also have the jpc12 and the chelegance mc-750 both fantastic antenna's and I have made the heavy duty adapter's to convert from M10 to 3/8 24 unf so I could experiment with different loading coils and the slide winder works well with the jpc12 and expands it down to 60 meters as well haven't had the time to test it out on the mc-750 yet, also have the mfj-63 coil wich should take both antenna's down to 80 meters, going to build a coil for the mc-750 for top band just for a laugh 😁.

[@COASTALWAVESWIRES]

@@adam-g7crq I actually thought about that for the 3/8-24 to M10, great to hear it works, thanks! Good luck on the top band my friend 😂

[@t.j.speakman7723]

Hey Walt, Thank you again. You've answered about 5 questions for me that I thought of after we chatted about the telescoping antennas. Always solid info. 👍

[@COASTALWAVESWIRES]

Thanks so much for watching and commenting!

[@KC3UVF]

Overseas shipping is usually not that bad. It never hurts to shop around. Back during the pandemic I bought an amp from Thomann over in Germany because nobody here in the states had one. I had it in 3 days and even with shipping it ended up being cheaper than going through Sweetwater or the like. I have the WRC sporty 40 and their 17ft whip. Both very solid. It's hard to go wrong with WRC.

[@COASTALWAVESWIRES]

Oh Sweetwater, don't get me started on the music gear I've bought from them LOL

[@KC3UVF]

@@COASTALWAVESWIRES Sweetwater is great. I tend to patronize an outfit out of jersey more often if I have to go outside my local shop, but I've never had a bad experience with Sweetwater.

[@RESlusher]

Good stuff as always, Walt! I use the Wolf River Coils SB 1000 too. I've recently added the magic carpet (two 25' steel screens). I also bought a second collar for mine and have it already tuned for 40m so when I want to switch bands all I have to do is move the jumper. What can I say, I'm lazy! 🤣

[@COASTALWAVESWIRES]

Thanks! You’re not lazy, you’re resourceful 😂

[@billbolen8115]

Thank you for the great review. I have a Wolf River mini. It fits in my backpack nicely and works well with my G90.

[@COASTALWAVESWIRES]

Thanks for watching and commenting! That’s a perfect combination

[@acestudioscouk-Ace-G0ACE]

I love the points you make from practical experience. I learnt a lot from this and will use it when I build my own coil.

[@steveb.548]

Great video as usual Walt. After watching your first Slide Winder vid, I purchased the M1ECC Slide Winder and really like it. Mine is the darker emerald-green, which perfectly matches the green of the inexpensive folding "mil-whip" that I previously purchased on Amazon. Since the international shipping is a bit high, I decided to make it worthwhile by purchasing the full slide winder ground spike and six section screw together whip. I really like that the multi-section screw-together whip is easily scalable by leaving off an upper section or two, and that the bottom two sections are both threaded 3/8-24 so you can raise the loading coil up by either one or two segments for mid loading. Like Walt, I have found that combining the sidewinder coil with my existing compact 6 section folding mil-whip makes for a super convenient combo - but I would add that it's nice to ALSO pack it up with at least the bottom two M1ECC screw-together antenna sections, because with this hybrid kit, the 6 section mil-whip can be used by itself for a super quick deployment, or combined with the lower two screw-together sections to raise the loading coil to a mid-loading height for more convenient tuning and higher radiating efficiency on 20, 30, and 40 meters 👍

[@COASTALWAVESWIRES]

Thanks! Great portable setup!

[@JoJa015]

You can also 3D print one of these and with some electric fence wire and a few other parts make your own. I recently did that. I have not had a chance to try it yet but your video has inspired me to try it this weekend.

[@COASTALWAVESWIRES]

Get out there this weekend, it's going to be a good one!

[@robertj6950]

Great video. I use a 7 section military man pack whip for use with a homemade coil. For frequencies higher than about 14MHz I just fold a section down and it’s no trouble.

[@COASTALWAVESWIRES]

Thanks, yes that's a great option I probably should have mentioned in the video. Thanks for the comment.

[@UABFWSS]

I roll with wolf river sb1000 on the truck with a 78” ss whip on a heavy duty cb spring (good over 100mph and offroad). Always just QRP w/705. Can tune from 10m-80m. Also have a mini, a ranger 80 and slidewinder. The wrc is by far my fav. Found an odd thing, that yields the best swr’s for my truck. Essentially 8 wire radials a few feet long, like a horses tail, just laying on the truck bed, beats any other setup (on my half aluminum truck). Sometimes I just click the collar between the bands (to a “random” length) on the coil and run with the ah705 tuner. All fun stuff to tinker with.

[@COASTALWAVESWIRES]

That's awesome, thanks for sharing!

[@grahamauld8894]

Great tip about the horse tail. I'll try that on my all aluminium Land Rover. (forgive the UK spelling of aluminum)

[@UABFWSS]

@@grahamauld8894 yes, aluminium, I’ve starting to say it that way at times, lol. There’s some radio voodoo that exists with my truck (newer fore ranger). It just took loads of trial and error to get it sorted. I will say, the wrc provides the most consistent, lowest and most spot-on repeatable performance. The other two wouldn’t yield as low swr #’s. Likely due to the lack of ability to fine tune as precisely with the slidewinder, but the ranger 80, as beautifully built as it is, just always had notably higher swr, sadly in every configuration attempted. It could be maybe reactance with the aluminium kayak rack, but the wrc handles it fine somehow. I had almost given up at one point, then stumbled upon the unconventional grounding method that made it all happy.

[@kumasu]

I'm late to this video, but where can I get that mag mount for my Wolf River Coils Silver Bullet Mini? Love your videos. Thanks! EDIT: Found it at DX Engineering. Have a good one, Walt!

[@whiskey2dna]

FYI: WRC has a Platinum 1000 now that will handle those higher wattages with no issues. It is insulated with a higher temp material with the same tuning characteristics of the regular 1000. I prefer the WRC as they are US based and the customer service is rated excellent if/when you should have any issues. Either way, lots of good info here. 73 😉

[@johnk23705]

Very good break down Walt. With all the variety of portable verticals out there, I think a person really needs to think about their use and the bands they want before buying any vertical. Both of the coils you showed are excellent. I also use a Buddistick. I think they perform a little better due to less ground loss using an elevated radial (s) (on the BP, it's actually the second half of the antenna, forming a "L" shaped dipole). Near salt water, I'd use the ground radials in the water. I stay away from the the Chameleon due to a pretty big loss in signal strength output due to the 5 to 1 transformer. I'd rather spend a few minutes tuning vs. being two to three "S" units down from a resonate vertical. 80 meters...Every coil portable vertical is very weak. Just physics. That said, contacts can be made. Very high "Q" on 80. In any case, I've had great contacts with the portable verticals I've used. All are a compromise, but will get you in many log books. 73 Walt !

[@COASTALWAVESWIRES]

Thanks and thanks for the excellent comment! 73, Walt

[@grahamauld8894]

Brilliant summary of those two choices. My conclusion? Buy both. The 3/8-24 v M10 issue is big here in the UK where we went metric years ago which is a complete PITA as all the best stuff has the USA thread.

[@COASTALWAVESWIRES]

Thanks! Great idea, buy both!

[@kennethblackwell1137]

Thanks, Walt. I have the Wolf River SB 1000, but have not got much use out of it so far...

[@COASTALWAVESWIRES]

Thanks for watching! This weekend will be a great time to put that thing to use!

[@AmateurRadioUK]

Really good assessment Walt. As you rightly said, it's not really fair to compare them as they are designed for different use cases. The M1ECC is designed to be small + light to carry & support small whips for lightweight portable operations (SOTA, POTA etc) while the Wolf River is designed to be more sturdy and support bigger whips for larger field day operations (such as club field days where you don't have to carry the equipment very far from the car & want to set up larger antennas). I have to confess that I've never got my hands on the Wolf River coil but have used the Slidewinder a lot for SOTA. Great to go in the backpack with the spike, some radials & a whip. Really quick to set up & easy to carry up a mountain. It's a bit short for 40m & being vertically polarised when working NVIS (which the majority of SOTA contacts on 40m in this region are) isn't ideal. Having said that, I think it's absolutely ideal for the majority of SOTA summits near me. It's become my go to antenna for SOTA & is probably my most used portable antenna. The only big problem comes if the ground is rocky & you can't get the spike in the ground!

[@COASTALWAVESWIRES]

Thanks! Yes I think the tripod was probably thought up for that very reason, not being able to use a spike.

[@Dihydrousoxide]

Thanks for the overview. Looking forward to the JPC-12 review.

[@COASTALWAVESWIRES]

Hope to get out with it soon!

[@zackaislabie5591]

Fantastic breakdown Walt. Thanks from a new Ham. VK6AAS.

[@COASTALWAVESWIRES]

Thanks so much for watching! 73, Walt

[@Tantalicdavid]

Great video Walt, Of course the Slidewinder DX is our favorite too.

[@COASTALWAVESWIRES]

Thanks! I’ve gotten a lot of miles out of mine (or should I say kilometers?) 😂

[@Tantalicdavid]

@@COASTALWAVESWIRES Most people in the UK of around my age grew up at school learning both imperial & Metric, As the Metric system came to the UK When we joined the EU in the early 70's

[@billcrow5403]

I borrowed a Radioddity HF-008 from a friend. This thing was a nightmare. I could not get 20m to tune until I used the short stinger and pushed it all the way down. My friend was using a single mag mount. I could not get it to tune at all. I put it on my 3 way mag mount and finally got the analyzer needle to move off 3+ swr. Like I said, I had to push the short stinger all the way down. Length was about 20”. That cured me wanting one.

[@COASTALWAVESWIRES]

That’s too bad, mine works pretty decent. Not a DX monster or anything but tunes and I make contacts.

[@wildbill1]

Thanks again for another cool video. Keep ‘em coming

[@COASTALWAVESWIRES]

Thank you! God willing I'll keep plugging away.

[@BobBroeking]

Love my WRC …. Activated a park yesterday am on 40M with 1.2 SWR. Do you know of a ground spike that will work well with the WRC that is more cost effective than their $50 version? I would leave the JPC12 in the box….. pretty frustrating product…I sent mine back.

[@COASTALWAVESWIRES]

I don’t know of a specific spike but You could probably cut down a regular ground rod and make one.

[@wattsandhertz]

I have used the JPC/PAC 12 for nearly every POTA activation that I have done. I also take a 5.2M whip with it and have compared the whip to the loading coil on 20 meters. The standalone whip is much easier to initially tune but once you have the coil setup it is just as easy. One of my videos from a couple weeks ago shows that whip setup getting over to Europe from a park on 10 watts on the X6100. For the cost they are a great antenna. I have also compared it to a 20 meter dipole with similar results. The dipole is super simple when it comes to setup but the nice thing about the PAC 12 is that you will always have ground under that you can likely stick something in where you will not always have trees to hang a dipole from. I have a video coming out on a tripod I built for it soon.

[@COASTALWAVESWIRES]

Great info, thanks for sharing!

[@RicSpivey]

I have a buddistick and I want a wolf river coil! Going to different locations the buddistick coil has to be adjusted and that takes way longer than a simple sliding coil would. I'd prolly make a frankensten buddistick pro with a wolf river coil mini... or throw the wolf river coil on a ground spike I make with connections for 8 ground radials.... Lots to do! And It's coming into the season where I love getting outside!

[@COASTALWAVESWIRES]

Yes it is coming into the perfect time for portable.

[@rjollis]

Nice overview Walt. I haven’t tried the Sidewinder or Wolf River products yet, but the Sidewinder is in my Christmas list now. I do use the PAC-12 /JPC-12 that you mentioned. I love its simplicity, portability and compactness. And it performs extremely well with my G90. I don’t mind the metric fasteners. (But ya gotta be careful and check the ground spike if you travel by air! I had my spike confiscated by TSA. What was I thinking?!) Looking forward to your take on it. Coil antennas of course have been around forever. I had a HyGain 18V when I was a young teenager going on vacations with my parents. It worked well once it was set up but was much more of a pain to build with the aluminum tubes and hose clamps. And the coil tap was a pain to adjust. Todays manpack whips and telescoping whips are fantastic for travel. On my bucket list when I find some time is to play with phasing of two (or three) simple verticals for directionality. For an HOA resident, it is a much more stealthy way to beam a signal than with a yagi, delta loop or quad. Thanks for the video. 😊Interesting as usual. 73 K8YX

[@COASTALWAVESWIRES]

Thank you for watching and the great comment! 73, Walt

[@axi6ne8us]

I have the Mad Dog 80 coil on a 2nd floor lanai on a magic carpet, but I'm getting 3+ SWR readings using the IC-705 on all bands. Do I need to ground the magic carpet? Why the SWR is in the red? Can't seem to figure it out ... 73

[@COASTALWAVESWIRES]

it must be the magic carpet, If it's elevated and not on the ground I'm sure that is the problem. Play around with some wire instead if you can and see if you get better results. 73, Walt

[@GarenEvans]

What do you think about the Big Kansas Coil?

[@johnrees44..G4EIJ]

Another interesting and informative video, Walt.. Thank you.. 73..John..G4EIJ

[@COASTALWAVESWIRES]

Thank you John! 73, Walt

[@kendebusk2540]

I just got the MFJ 1899, hadn't watched this one yet. I have not yet tried it, but I'm interested in hearing how you mounted it on the pizza pan (I think that's what it is?) and your counterpoise which appears to be alligator clips on the side of the pan. Is that a mag-mount with a BNC connector built into it? Thanks, de KA8VLW, Ken, Michigan

[@COASTALWAVESWIRES]

Hi Ken, I did a video on it about 2 years ago. It was one of my first videos and I cringe watching it but here's a link, I go over everything in it: kzbin.info/www/bejne/fXXOfohunqxsnaMsi=hz5Uca8Ti748F4yl All the best and 73, Walt

[@joygonzalez7457]

Hey neighbor, over here in Williamsburg VA. Quick question, I have a Chameleon 17 ft whip and a Mad Dog coil and am using a ground screen. When I’m tuning the coil for 10, 20, 40 meters am I leaving the whip fully extended and just adjusting the collar on the coil? Thanks in advance, huge fan of your channel!

[@COASTALWAVESWIRES]

Hi neighbor! The problem with using the big 17 foot whip fully extended with a coil is that what you’re trying to do is tune the antenna to be a quarterwave vertical with the coil. A quarterwave for 20 meters is around 16.3 feet so all the bands above (17 thru 10 meters) are even shorter. Fully extended will work for 40 but you can trim the 17 foot whip down to quarterwave resonance without even using the coil on the higher bands or just slide the telescopic whip down to about 8 feet and tune with the coil. I hope that answers your question and helps. 73 Walt

[@joygonzalez7457]

Thank you! I will get out today and give this a try, really looking forward to getting into POTA but first need to learn to tune this antenna 😂

[@ryank5tar]

Nice video Walt. If I purchased that wolf river coil antenna, I would be tempted to paint that pipe purple and re wind it.

[@COASTALWAVESWIRES]

Thanks! great idea

[@dawgrules1]

Thanks Walt, can such a coil be used in the rain ?

[@adamny5e591]

I discovered that a Stainless “hose clamp” replaces the collar on the WRC to make tuning S M O O T H ! Easy conversion that is just as easily reversed. It’s a game changer as the WRC often requires two hands to make fine adjustments. The SS clamp eliminates the hassle.

[@COASTALWAVESWIRES]

Great tip, thanks!

[@grahamauld8894]

Very great tip.

[@darrentilley9495]

Great video Walt 👍 the slidewinder looks easy to setup and use MM7FJI

[@angelscomputers]

I think the best of both worlds (and im going to try it soon) is to have the Silver Bullet and replace that clicky PVC part with that clamp which I already found in Lowes for pennies, waiting to add a terminal and test it soon. Then I will have up to 80 meters with a nice slider because I really hate that clicky PVC slider from WRC

[@TMECTHUK]

Great video. I am using a Clansman Prc 320 manpack British army radio. what I am trying to achieve is a shorter Antenna that can be more user friendly for a hill race that requires 35lbs plus to carry and I would like to send voice or Morse over a good distance. The 2.5 meter whip antenna and spring fitting moves too much and could potentially hit other racers. I would like to know if there is an alternative shorter antenna that could work on Hf 320 2 to 29.999mhz . many thanks J

[@COASTALWAVESWIRES]

Thanks! Take a look at the Buddipole Long Telescopic Whip. It’s lightweight and pretty stout. You could adjust the height down to suit: www.buddipole.com/lotewh.html

[@davem7847]

Probably a dumb question, is the bandwidth of the larger circumference Wolf Wolf River Coil wider than the smaller Slidewinder DX? Slidewinder DX?

[@Justin-u4w]

Could you use your 7 element with the coil to tune in 10M and 12M to a 5/8 wave so you have 10m - 40m without needing a second whip?

[@COASTALWAVESWIRES]

Good question but you would need a way of matching the impedance of a 5/8 to the 50 ohm coax. So the answer is yes and no, you could do it if you added an inline transformer (unun) and then tuned it but to be honest that would be a pain

[@J123G]

You can purchase an adapter to convert m10 to 3/8-24 for your JPC12.

[@COASTALWAVESWIRES]

Yes I will do that, thanks!

[@hughpatterson1480]

As always, I learned about coils. I wanted to see if you used them before purchasing one (I trust your opinion). Thanks for another great video..73..KN6KNB

[@mcdonald1743]

Mp1dxg super antenna is what I have. I love it.

[@KS0JD]

You better get on 80M. You never know when you will want to have a QSO taking about all your ailments. Hi Hi 73

[@COASTALWAVESWIRES]

Hi hi I hear you Jeff!

[@keithdalton3004]

Thanks Walt

[@COASTALWAVESWIRES]

Thanks so much for watching! 73, Walt

[@dfwpiper1]

Thanks for the helpful infos. You sound exactly like Biff Tannen. You should say 'Butthead' more in your videos.

[@COASTALWAVESWIRES]

LOL, thanks for watching

[@pasjeihobby]

Unfortunately good telescopic vertical and epic coil are still on my shopping list :( Anyway, great video 👍

[@COASTALWAVESWIRES]

Thanks! hope you get one soon!

[@honeybadger6127]

I enjoy making my own

[@dangermandave67]

Why doesn't the smaller coil work with the 17 ft whip?

[@KE8ODY-WV-Ares-Ham-Dad-3O4]

Could be used on my deck!

[@dennis8019]

slidewwinder amazing ....

[@COASTALWAVESWIRES]

Yes it is!

[@twkolejofil]

If your aesthetic sense doesn't accept the PVC pipe markings, they are sometimes removeable with some alcohol 😉

[@TheRiddleNL]

Noth ;)

[@jeromeGrzelak]

if it works use it kg6mn

[@COASTALWAVESWIRES]

Roger that!

[@Wildlandfirefighting]

SQUIRREL!!🐕

[@tittiger]

You go through a whole slew of antennas, but you provide no links in the show notes to actually find out what you're talking about. That is very disappointing.

[@billstaats1817]

Always good information! Thank you, 73,,de K6ZTM.

[@COASTALWAVESWIRES]

Thank you! 73, Walt