K4OGO Coastal 20 Antenna - Tweaking and Improving

Experimenting and improving my Coastal 20 antenna design. Taking it to version 3.0 #hamradio #hamradioantenna #portablehamradio

[@pasjeihobby]

1:14 screenshot as usual. There is something magic in handmade schematics that makes it easier to digest for me 🤔 73

[@KeystoneInvestigations]

The antenna is up The radio is on And we're all set to go With help from Walt The log is full Our thanks to K4OGO!

[@carypeaden4147]

You talked with Finland, and you at least heard Australia and Ukraine. Did you talk with Australia and Ukraine (did they hear you)?

[@COASTALWAVESWIRES]

Yes, I only posted their side of the QSO, as you can see in both they repeat my K4OGO callsign

[@mobiltec]

Love it. Gotta get that 4:1 Balun.

[@richiec7602]

Good morning Walt. I was going to ask you if you used an antenna analyzer but you answered my question when you said that you recently got a nano vna. I like watching you build and using antennas. Always great videos. 73 from West Palm Beach, FL. KQ4LOQ

[@tnoldforester]

Hey Walt. Thanks. I am a new HAM. Just bought a G90 and coupled it with your 17-5 crappie pole antenna with 4:1 balun and two counterpoise 3’ wires in my backyard. Not much saltwater in TN. Freshwater? SWR @ 20 meters was 1:1. Other bands weren’t too bad but required tuning. Works great. Thanks. Next projects are a Rybakov and EFHW, but I need a longer pole. Great videos! KQ4RGB

[@COASTALWAVESWIRES]

Thanks! You’ll love the Rybakov. 73, Walt

[@robertmeyer4744]

great antenna. made 2 different antenna's out of same wire. random wire with counter poise. the UNUN 4:1 the outher a off set center random with 4:1 Balun . both work and have different pattern. 1 better DX the outher better NVIS . the outher way is like the MFJ 2010 off set center. that uses a 4:1 Bal Bal into a 1:1 Balun. the outher way to do off set center. the outher way is 75% to 25% wire length. still a dipole. just moving the feed point. 73's

[@unclemikeyplays]

You got Australia on 20W with that thing. I'll never say something cannot be improved, but I'd say you're definitely on to something with that antenna!

[@vk4foo]

Now I'm going to have to build a 4:1 balun to play with. Good work Walt. F👀 ~ 👽in Asia

[@josephgomes8543]

That was a good experiment, and very nice results. Man I really envy your weather at this point. Chilly and windy here. New England Spring as opposed to Virginia spring. 73

[@garyh8315]

Hey there Walt. Just looking at that fence. Is the wood held with twisted wire by chance? (Chestnut fencing)? A great vid, yet again.... you are the man showing how to make this hobby work. 73

[@COASTALWAVESWIRES]

Yes that’s exactly how that fence is built. 73, Walt

[@JS-oq2cd]

You'll love the VNA...best thing since sliced bread. It would be great to see a full multiband sweep instead of each band segment on the G90. Both the 29' and 20.5' OCF's are going to be my main antennas out on my 3rd floor fire escape. Try adjusting the length of the shorter wire on the 20.5.

[@DXCentral]

Love it! I used to love to take my FT-817ND and the Buddipole down to the beach on Sullivan’s Island in Charleston and take advantage of the Atlantic model saltwater amplifier. I haven’t done it here yet in Louisiana yet, though I have a good one with Lake Pontchartrain right here a mile away. Now your video has me itching to give it a shot, my friend! Hope all is well!!’ 73 and best of DX!

[@COASTALWAVESWIRES]

Hi Loyd! Hope all is well. 73 my friend!

[@NickelodeonTuber]

The nano vna is a great tool but nothing beats getting out there and doing it, Walt. Those are your words! That's why we subscribe - That's what you do! Have fun my friend!!

[@HowIDoIt]

I heard your first contact you featured on 20m to VK3EY, well I heard the VK side here in South Central PA. I informed him when I contacted him right after you from my g90 on my homemade 40,20,10 fan dipole, why your call sounded familiar 😁. Was hoping to track you down on the bands, but did not cross waves. Love the videos, thanks Walt. 20 to VK was well open this am during the grey line. Coming down to OBX in August maybe we'll run into each other on the beach!

[@danielzdanowicz6899]

You have some very good ideas there Walt. It is worth looking into for me here in the condo. You were getting great results too. I am very impressed! Best 73's Dan K1YPB - On the air since 1962

[@airheadzradioadventures]

Great job, Walt!

[@COASTALWAVESWIRES]

Thank you!

[@forgetyourlife]

So why a Balun when both sides are unbalanced?

[@COASTALWAVESWIRES]

Experimenting for results

[@StreakyP]

if you want a small radial free 20m antenna that doesn't need an external balun, unun or ATU check out the old "Shorty Forty" antenna & just halve the dimensions (radiator & coil.. but keep the same number of turns on the coil) so 18.5 foot long total, centre fed, Co-ax screen to centre of coil & main conductor tapping in 2 or 3 turns out. For 15m make the centre coil plug-swappable & just have a smaller one for 21MHz I've not tried it on 10m but as it is a smidge longer than a half wave dipole it will probably need a capacitor to shorten it rather than a coil to lengthen it. For self supporting coils I use 2mm electric fence wire that comes in multi-hundred m drums & is cheap as chips so there is no worry about the cost of a play. For quick connection of the coil to the antenna it is worth checking out Wago snap connectors.

[@MrStanwyck]

I really enjoyed your video Walt. I’m looking forward to seeing you conduct more testing with your Coastal 20. When I take the family to Ocean City , MD, this summer I want to play radio on the beach. I want to use a vertical antenna like yours that doesn’t have radials for people to trip over. So far I’ve been thinking about using my Chameleon MPAS vertical with the one 25’ counterpoise or my CHA Tactical Delta Loop on a 12 foot pole. Bill KC2KNA

[@COASTALWAVESWIRES]

Thank you!! 73, Walt

[@TheRdeanpeek]

ever tried a helium balloon or kite, instead of a pole to get your wire up in the air ??? that would be an interesting experiment for your viewers....

[@COASTALWAVESWIRES]

I have a kite and plans to do that this summer!

[@kandkmotorsports]

Now I have to try another antenna!! ;) Thank you Walt!!

[@northwoodsyankee3528]

Good stuff man. I'm always learning and getting new ideas.

[@n5copfrank931]

Hi Walt. Great video as usual!! Just curious if you have a link to your drive-on mount for the 10m mast ? I have been using a Spiderbeam mast and haven't been able to find a reasonable priced drive-on that will fit the mast with the bottom cap on ( 66mm ) Thank you for any advise you can pass on. Keep up the great work!!!!! 73's N5COP / Frank

[@COASTALWAVESWIRES]

Hi Frank! Thanks! Yes, I got mine on Amazon, here’s the link: a.co/d/8UUcxm3

[@skrattswalk1928]

Great stuff Walt. I try to set up once or twice a week portable here in PR with hamsticks or wire and G90. 20W is a challenge but still make great contacts well over 4000 miles. I love it. Keep coming with the ideas. 73 KC1RDY.

[@LB9HI]

4:1 is a very good choice. I plan one on mat 61 for the upper bands and 43 or 52 for the lower ones. It was very nice experiment and many thanks for sharing the results!

[@MobiusHorizons]

I am a new ham KK7RWK got my license in March. I have really appreciated your videos, and have taken inspiration from them for building my own antennas. I have a 40m skyloop at home right now, but plan to build a rybakov or some variation of your coastal 20 for portable operations. I'm trying to break into POTA, but the 10w from my x6100 hasn't been enough from the particular park / antenna combination near my house to activate (despite 3 attempts). Thanks for your videos, I hope to catch your callsign on the air one of these days.

[@judhi]

I appreciate the use of metric system 😊👍

[@F4LDT-Alain]

So do I 😁

[@Johann-ZS6L]

Feet to meters = ft x 0.3048 Inches 1 = 25,4mm

[@WayneDowning3382]

Ahh thanks Walt. I did see this video, just didn’t put two and two together since it was one of the few videos I didn’t take notes from. I do the note thing from time to time for my own little brain book and ‘try this out’ isms lol. Thanks again!

[@spython1553]

Hi Walt. I really enjoy your videos. What were the final lengths of the poles that you used with the 4:1 baking? It looks like the feedline was placed higher than your previous version of this antennae

[@COASTALWAVESWIRES]

Yes the feedline was higher. The top of the antenna was at the top of my 10m pole.

[@JeffreyWilliams-x4x]

As always nice experiment! Can't wait to try some of these when this bi polar upstate ny weather breaks! I plan to use a multi tap unun that N8NK taught how to build on KZbin my experiments have been going great with this ! Thanks Walt 73

[@davidjohnson497]

OH HELL YES! Thanks for the update Walt, this is Dave also an antenna experimenter. Such WOW results on 15m, keep the DX flowing! Keep getting out to use the antennas and keep looking for the DX on low power and keep HAVING FUN with RF. Way to GO!

[@weslewis8748]

Just now built a Coastal 20, Walt...looking forward to taking it to the beach next week to test it. I'll use my 4:1 UNUN since that's all I have (from my Rybakov build) ..it seems to make more sense to me, however, to use the UNUN ...with the driven element-to-counterpoise ratio so high. It would be fun to do a comparison on the RBN within minutes of each....with a 4:1 UNUN and then 4:1 BALUN

[@W4BTK]

New knob!

[@davidhaman4642]

Really enjoy your videos Walt. W8BLT

[@COASTALWAVESWIRES]

@@davidhaman4642 thank you!

[@johnnorth9355]

I bought a Nano VNA a couple of weeks back and it's a revelation and has unseated a lot of what I thought my antennas were about. I use a mat30 tuner on my 450D which makes it very tolerant but I will pay a lot more attention from now on to the antennas (1x vertical and 1x efhw). Just got to convince the wife I can go up ladders still lol. 73 M7BLC.

[@F4LDT-Alain]

(Just realized that I already commented here. Senior moment. Oh well) Hey Walt, been following up on this whole Coastal 20 story a bit late. Now totally convinced that it's an antenna I must have ready in the trunk of my car for another upcoming vacation in Brittany. Many thanks for all the tips. Now grabbing the 4:1 balun that came with my (yet unused) M0CV0 HW-20HP and a LDG 4:1 unun I bought last year and going to cut some wire to prepare a kit. Talking of these LDG baluns... not sure I will open this 4:1. I did with a 9:1 and I was extremely disappointed with their build quality. Definitely not worth the high price (around 50 euros) we pay for these here in continental Europe.

[@dandypoint]

Looks good. Will be interesting to see Nano VNA impedances on the various bands. You mentioned 15 meters and that got me thinking I don’t think you can beat that antenna on 15 meters with any other vertical as it is close to a half-wave long. Resonating it in the middle of the 15 meter band should give a purely resistive feed impedance would be maybe 250 to 300 ohms. So a 4:1 transformer or slightly higher would be good and that’s what you are using here. Consequently you are so close to perfect now that I don’t really think you could do any better by resonating it. Having a halfwave vertical on 15 is quite a good antenna! Do you have any idea where it resonates in that configuration? I am guessing slightly below 15 meters. If so you could shorten it and still be really good on 15 meters. Probably not affect the other bands at all.

[@Keith_WB2VUO]

Hi Walt. Just a quick thought about your great 15 meter performance. The 20.5 foot length is almost a full half-wave on 15 meters. Granted, it's not resonant, but it's close enough to really enhance the performance on that band. My fave mobile/portable antenna is a 29 foot vertical with a 13 foot counterpoise. It's roughly 5/8-waves on 15 and the counterpoise is close to a free-space 1/4-wave on 15 meters. I visuallize it as a 15 Meter 5/8 Vertical. I feed it with a 9:1 Unun, the "Famous" EARCHI Unun, popular around 10 years ago.. The antenna is supported on a 10 meter mast supported with a home built drive-on mount. No beach ops and a pair of Titanium knees preclude much hiking & hauling here, heh... This is my primary POTA antenna along with 4 different Magnetic Loops I have built. 58 years in this hobby, and always ready to try something new! 73, de WB2VUO

[@rossbassette7518]

Walt, I hung a 20m off-center fed dipole vertically from a 12m spiderbeam pole, and was able to tune easily down to 40 meters. However, I was unable to get any 40m contacts. Also be sure and keep the coax running horizontal from the feed-point

[@W4TRI]

So 17.5 ft and 3 ft wit a 4:1 Balun to start? Perfect!

[@COASTALWAVESWIRES]

Yes making it 20.5 overall

[@daveengstrom9250]

How do you know if you need a 4:1 or a 9:1 or whatever?

[@COASTALWAVESWIRES]

It’s all about feedpoint impedance and mostly historical knowledge and designs. You can model antennas in software to see as well. Typically for verticals I use a 4:1 for 17.5’ and 25’ and the 9:1 for 29’, 35.5’ and 41’. It’s not limited to those lengths but that’s a good rule of thumb to get started.

[@chipweather]

Do you have any tips for running an antenna out of a second floor window down too the ground? I have been having issues with getting my efhw that is resonate when Im on ground but not when its up high. 73

[@COASTALWAVESWIRES]

Add a 6.5 foot counterpoise wire dangling from the feedpoint out the window. I did this In Poland with an EFHW I ran out a second floor window and it worked great.

[@chipweather]

@@COASTALWAVESWIRES thanks I will try

[@jerryKB2GCG]

Looks like a great antenna, have a link to the design ?

[@JS-oq2cd]

The graphic in the header has everything you need.

[@COASTALWAVESWIRES]

instagram.com/p/Cp4kJCtj6NZ/?igsh=MTc1bDRtNWI2YjZ4Zg==

[@joekrepps]

DEFINITELY try 15m!! It's been my go-to band for a while now. I have to go back to late January to find my last 20m QSO and I'm 74/100 towards Mobile DXCC, in a little over two years. Setup is a FT-891, between 5 & 50 watts...because any more is pointless (as you know) SSB, into an ATAS-120A on a triple magnet mount on my Subaru wagon roof. if 10m is closed, I don't hesitate to go 15m and if that's dead, I'll eventually get to 20m. QRZ Logbook is current under WB3CFN if you want a look. LOVE your videos!! Hoping to get something going at home with one of your designs. (I'm in an HOA condo so, temporary antennas are okay but anything semi-permanent has to be stealth.) Thanks, Walt!!

[@christophermarshall5765]

Nice work Walt. 4/5 to VK3 Victoria Australia is a great signal for the distance.

[@hikerglenn]

I would definitely be up for a 15m design, Walt. Been doing more 15m DX contacts lately and it’s been working good! 73-de N4LOX

[@F4LDT-Alain]

Hello Walt! "Pretty cool"? it sure must have been. I'd be jumping all around if I made such contacts 😁 Anything over 20M was rather quiet here yesterday, and even 20M wasn't all that great. Made QSOs from all over EU on 40M with the G90 and my 7.6m Rybakov antenna inspired from one of your previous videos, but not much further. The "Costal 20" sure enters my list of antennas to try. In a month or so I should be able to enjoy the saltwater boost too. Getting ready for this! Thanks for your always fun and inspiring videos.

[@MikeN2MAK]

I’m gonna need to try this antenna again-it’s been a while.

[@weslewis8748]

Why wouldn't you use an unun...since the two lengths (ant and c.p.) aren't equal

[@kurtzFPV]

Would mounting it directly to the jeep at least give it a bit of a ground plane?

[@billchinook3292]

Hey Walt!! Any new updates or "tweaks" to this antenna?

[@anthonyfranz8317]

This video shows it's not the radio, but it is the antenna that matters.

[@n0vty873]

AWESOME!

[@eagle9800]

Looks like another aerial im going to have to build. Don't have a 4.1 balun but do have the 4.1 unun. Different knobs or radio? 73 Steve ZL1YX

[@jameslarrimore1419]

KC3YUN here in De.learning from you keep up the great work

[@Steve-GM0HUU]

👍Good going Walt. Some nice and impressive contacts.

[@markkoehler5110]

I like these antennas! I have to try that at my rural property

[@weslewis8748]

Why wouldn't you use an unun...since the two lengths (ant and c.p.) aren't equal

[@COASTALWAVESWIRES]

I’ve used a 4:1 unun in the past, this was an experiment and I went with a balun because an Off Center Fed dipole uses a 4:1 balun as well. I wanted to see the outcome and obviously it was a good experiment as you can see in the video

[@corewarrior]

Look forward to your nanoVNA reports.

[@Philip-KA4KOE]

No more orange tipped knobs.

[@N4GW]

Nice antenna

[@Philip-KA4KOE]

Crack of the crack, we call it.

[@daveh7720]

This is really encouraging! I saw your original Coastal 20 video and the idea stuck in my head, so this month I started trying to build one. But instead of the 9:1 unun, I built a 4:1 Guanella balun for it. I just finished that today, so tomorrow I'll cut some wire and string it from my 7 meter fishing pole and see how it plays. Thanks for always trying new stuff and then posting videos about it. Your channel is a great source of inspiration.

[@COASTALWAVESWIRES]

Thank you!! 73, Walt

[@daveh7720]

@@COASTALWAVESWIRES Follow-up: I set up the Coastal 20 with the Guanella balun and the G90 was able to tune it to SWR of 2 or lower on every band from 80 to 10 meters. I cut it a little long and it seems to like the CW portions of the bands better, which is fine with me.

[@Johann-ZS6L]

Yes it's nice for 20m but will you propose for multi-bander / broadband for freqs 3,5MHz to 30MHZ... ????

[@COASTALWAVESWIRES]

I don't operate much below 40 meters so I'm probably not the guy to give you that answer. 73, Walt