MFJ-2104 Octopus Antenna, Four Dipoles of Fun!

[@jsieb]

I love the golf bag setup! Great Video!

[@HamRadioCrashCourse]

Thanks!

[@AndrewMurphy8383]

@@HamRadioCrashCourse i owuld love to build the antenna were did you get the mount to screw in the ham stick

[@W4TRI_Ronny]

Great new twist on a very old idea. My elmer had a multi leg antenna at about 20 feet that worked well. It is in the ARRL antenna book. For those without trees this is great!

[@HamRadioCrashCourse]

I'm a no tree guy, this works out well for that!

[@CaroleMinxBlanton]

Thx I'm surrounded by very tall trees

[@mewrongwayKOCXF]

In 1981 I built a 6 band Octopus out of electical boxes and rewound Firestick cb antenna's. My first contact was on 15m with an AH2 in Guam.

[@AD6DMDennis]

Imagine the performance when you add a little bit of whipgrease! Thanks Hosh, I saw this antenna and was wondering about it.

[@redjohn20001]

You could use Hamsticks for the higher frequency bands but for 80m or 40m run a wire dipole using pl259 connectors from a set of the ports for a more efficient inverted V antenna.

[@KX4UL]

Cool antenna(s)! Using the Golf bag.....brilliant!

[@BryanTorok]

It is interesting that I was watching your review of the Shark Ham Sticks on The Chameleon Spider and Quad Dipole Ham Radio Antenna video that you made February of 2022 showing the "made in America" Shark version of this system, when this video cam up in my recommended list.

[@murphy15108]

Thanks for the review. I’m thinking of buying it and you helped me a lot.

[@brianmaier7529]

I love the cap you're wearing.

[@davidsradioroom9678]

What a great idea! Another antenna system to pursue in my search for the best portable antenna. Thanks!

[@HamRadioCrashCourse]

thank you for watching!

[@brucesteele3052]

Me: camera bag for my gear. You: golf bag for the antenna. love it de w0vet

[@namdogtag]

Nice video! I have two of these MFJ 2104's. I use one for FD and the other one for my home station setup. Also I have double original "Larson" ham sticks for each band 6 through 80 meters. I mount these (at home) at 30 ft on a telescoping mast. I have 4 bands being mounted. The results have been fabulous! Out does my Hustler 6BTV vertical a mile 20 radials on the vertical! 73 K8ESE

[@k7ilo_Las_Vegas]

Whats funny about this is, a guy who I had talked to because I had questions, designed and built this some years before MFJ even thought about this using a metal J-Box and the proper connectors, and I mean years before. And this design has been suggested for HOA type situations well before MFJ. Oh well.

[@K6UDA]

Stand by for my take on the the octopus when I try it out for the first time at Quartzfest in two weeks.

[@HamRadioCrashCourse]

Can't wait!

[@amsoiltek]

@@HamRadioCrashCourse Hello Bob and Joss, I have/had the Big Ears but the winds took it down at the campground the only thing left is the center section. I was thinking of getting the Octopus for QartzFest too Bob but still not sure yet. So I'll be looking for you at QF. Like you said Joss I hated having to always retune the BigEars every time I changed bands. 73 de N6OIL

[@HamRadioCrashCourse]

The Octopus will be more wind resistant as its balanced. As you noticed, aside from initial tuning there is little additional work you have to do on different bands. In either case though, I recommend staking the antenna down and better guying it if you're going to be in wind at QartzFest.

[@amsoiltek]

@@HamRadioCrashCourse Joss, did you notice any directivity with your setup?

[@HamRadioCrashCourse]

No more than a horizontal dipole.

[@mikesimpson7748]

Golf bag was a great idea

[@HamRadioCrashCourse]

Thank you!

[@richardsmith9634]

What would happen if you installed 2 or more pairs of hamsticks of the same frequency (e.g. 20 meters). Would you then get a multi-directional dipole to save you having to rotate the it ? Just thinking of a limited attic space application where you could have two oriented east/west and two oriented north south

[@HamRadioCrashCourse]

I assume it would take on really weird lobes that would be hard to judge the pattern on.

[@kylefreemason]

Could you do a video for new hams covering in simple terms when baluns and ununs are used and how to know when 9:1, 49:1 are necessary etc. You put out great videos!

[@wildlandoutdoors51]

Would this work well for a base antenna? Thinking it might be worth getting and mounting to the roof

[@wjess3569]

Thanks. I don't have the Octopus.. but I do have the MFJ-347 dipole mount. Do you recommend any sort of balun on this.. or, simply attach the coax and you're done?

[@HamRadioCrashCourse]

You could add a choke balun

[@gregbarthol5381]

How does the magic work when the hamstick meets the mount? I can not figure out how the positive & negative pass through the hamstick base to the antenna seeing how it is all metal

[@HamRadioCrashCourse]

Ham sticks are just one unbroken wire really. Half of the ham sticks connect to the negative. The other half to the positive.

[@fm71450]

Dear Dr. Josh, thank you for this. It is 3 years down the road, from when you made this video. For me, After long hours researching antennas, radios, coax, etc., I am preparing to get my first HF rig. We live in the country, no HOA. There are lots of trees, and 50’ of coax will not get me above them. No $$$ for a decent 50’ antenna mast, either. There is SO MUCH TO LEARN, but, I just want to get started - I can improve my rig down the road. For now, something that IS (potentially) portable, (although it will likely stay in our yard 99% of the time) like this may help me get out on 10m, 12m, 20, and maybe 40m. It is understood that you are very busy. Would YOU use this for your base station antenna?

[@mnastreeservice]

Great video !

[@chuckk5358]

Golf bag antenna caddy, cool!

[@lousadventures2111]

I have a 60 foot tower. now I know what to attach to it. so it's 1 antenna for each band correct?

[@cmd0405862]

I'm wondering if you could use this Octopus for a perm HF antenna mount. I have an HOA and thinking I could run this up thru one of my trees and it would not be noticed. THOUGHTS ????

[@HamRadioCrashCourse]

Yeah, you could run is permanently.

[@bruehlt]

Love the concept for the antenna, but too darned expensive.

[@769270865]

If people look you weird with that big ear dipole, you are a mad scientist with this. And it is way too heavy for SOTA

[@HamRadioCrashCourse]

Yes, I agree, too heavy for all but drive-up SOTA, but well sized for field day.

[@unclecow]

That’s awesome 👏

[@johnkershaw9575]

Hi, Thanks for this. I was waiting on Dave Casler's review but he has been constrained by weather. How is this for DX. Especially if I put it up at 30 or so feet. I would like to use this as a semi-permanent antenna at home. Thoughts on this?

[@robertvulliet7747]

Hi John sounds like you have the same use case that i was thinking of. i could sees setting this up with an antenna rotator so i could aim the broadside of the band i was working. the only questio Im just wondering how high i have to get it away from my metal roof of my garage.

[@tglenn3121]

I'm wondering how this antenna would compare in performance with a wire dipole. Any comparison?

[@jordan1234564]

Is there a way to make it rotate, thinking about using it for a base antenna.

[@HamRadioCrashCourse]

There isn’t much reason to rotate it. Not much directionality out of a loaded dipole.

[@jordan1234564]

@@HamRadioCrashCourse okay that's good to know. Do you still use it to this day?

[@HamRadioCrashCourse]

Rarely. It’s kind of more something you wan to pack in a vehicle with a good tripod. I’m often more back pack portable.

[@jordan1234564]

@@HamRadioCrashCourse would you use it as a base antenna?

[@jdecar1]

What's the transmit efficiency of the ham stick dipole? I've heard that ham sticks are really inefficient below 20m making your ERP more like QRP.

[@leftturnaudio5678]

Made this years ago with a 4" pvc cap and stainless hardware for $25

[@MrM2hb]

Interesting option.

[@1958johndeere620]

The big ears I suspect would have better transmit results due to the elements being longer and closer to actual wavelength?? The octopus being called a rotatable dipole,,, at the height of most portable masts does rotating actually make any difference??Usually dipoles that are to close to the ground are omni directional. They do look great for portable ops.

[@HamRadioCrashCourse]

You can put any mast you want in there tho. My application was just lower to the ground.

[@1958johndeere620]

@@HamRadioCrashCourse Yup, absolutely. Peaked my interest.

[@tglenn3121]

Will this work on the FT8 area of 80m??

[@FranciscoCarmo1997]

Nice video Josh! 73

[@HamRadioCrashCourse]

Thanks!

[@MyTube4Utoo]

*F-O-U-R.......................bands of fun.* :-)

[@lukebizurk7601]

Would this work in an attic?

[@HamRadioCrashCourse]

if it’s big enough.

[@k9ats1]

@@HamRadioCrashCourse Glad someone beat me to it. I was thinking the same my attic is 26.5' wide. With 7' fully extended sticks that should be no problem. The question I have is how far up does the octopus need to be, for the sticks to clear the insulation floor? As the only thing I worry about is how much drooping flex there is, as my attic is 7' tall at the middle and narrows to near nothing at the edges.

[@fm71450]

MFJ BIG ears vs buddy pole vs chelegance 7?

[@thevacuumtubejunky9774]

Great video demonstration. I have a corny question. What would or could you use all 4 radial ( dipoles) for the same frequency, co-phasing/quad phasing ???. Would doing so create a friggen mess, how would the radiation pattern work, or would it?. Thanks for sharing!.

[@HamRadioCrashCourse]

I have no idea what that would do. Probably alot of mess. :D

[@769270865]

And the problem I always wonder is with a tripod, you almost will never able to get antenna high enough for the lower band. So how is the TOA on this?

[@HamRadioCrashCourse]

MFJ sells a taller tripod. I just didn't have it for the video review.

[@HamRadioCrashCourse]

Looks like 18' on this one. www.mfjenterprises.com/Product.php?productid=MFJ-1919EX

[@chrisn9140]

They also have 600W versions - not just 250W.

[@HamRadioCrashCourse]

Yes they do, which is a function of the ham sticks you buy.

[@itswift]

"Am I detained, or am I free to go?"

[@CaroleMinxBlanton]

Lol. That was funny

[@wcgems]

HELP!!! Anybody have issued with getting 40 meter sticks set up? I tried for over an hour and then went all the way IN as well as all the way OUT with the whip and then worked from both ends down an inch ar a time but the best SWR I could get around 7.175 was 4.7:1. I tried a few nore adjustments and finally gave up with it setting at 5.6:1. It really seemed to want to stay around the 6.8 Mhz area and could get it to give me a 2.1:1 there but nothing better ANYWHERE else with any adjustments. YES, I am using the 40 eter sticks, or at least that is what the bag and sticker say. I am using an MFJ Analyzer as well. I had no issues gettng the 80 meter to give me 1.2:1 at 3.8Mhz

[@dcmsr5141]

Cool device, is this like a disc- cone set up?

[@HamRadioCrashCourse]

No, these are all dipoles. Only a pair would be working at one time on transmit.

[@dcmsr5141]

@@HamRadioCrashCourse thanks for replying , I'm studying for my technician and I find this absolutely fascinating 🤓

[@HamRadioCrashCourse]

Awesome! Keep it up!

[@zorbathebuddha4969]

Great

[@HamRadioCrashCourse]

Thanks!

[@uggenstu]

Was it grounded? and, how?

[@raulandresmoch]

Hello, how you doing, so im starting on the Ham Radio hobby, I live in Mexico and everything here its so much expensive and hard to find. My sister its going to San Diego California in about a month, do you know any trusty store that sales Preowned equipment that I could buy from?! And ship to her Hotel?? Thank you so much for your help and for the great videos!!!

[@HamRadioCrashCourse]

What are you trying to buy? There is an HRO in San Diego.

[@raulandresmoch]

@@HamRadioCrashCourse First of all, thank you so much for the fast reply and the help!!! Someone offer me a Icom 706 MKII here in Mexico but I think its expensive, so maybe something in those lines or a UHF/VHF decent Radio and maybe later a HF only radio. HRO its the name of a store?! Or something like that?? Again thank you so much for your help and taking the time to reply!! Best regards

[@HamRadioCrashCourse]

Yes, I would start with a good VHF/UHF mobile radio or an HT. Then think about HF a bit later.

[@Blue-Collar-Radio]

Wow that antenna is pretty sweet!

[@johnyum9021]

is it like discone ant..

[@HamRadioCrashCourse]

Nope. It’s a multi and dipole.

[@piotrbienkowski1095]

Someone thought you were spying for Russia or Kim the Little Rocket Man ;-)

[@dannystephens7246]

HaHaHa! I spent 30 years as a Deputy Sheriff and I can picture the call coming in to dispatch. ( There's a Cuban spy out here in the park with a radio and he's giving away our country's secrets). Next time wear your camo gear and take a cigar with you!!!

[@BryanTorok]

You should have shown the interaction with the police officer. It would be interesting to see you explain what you are doing and get his reaction. Obviously, you were still there and he was walking away, so it must have gone OK.

[@HamRadioCrashCourse]

He came up when I had put the cameras away.

[@sp1wz208]

Nice :-)

[@ctscantechnologist]

I do wish it could handle 1500 PeP...

[@sgtshultz13]

There is a creeper in the park in a funny hat with a bunch of equipment. I think it is a meth lab or a rave.

[@HamRadioCrashCourse]

Maybe both!

[@heathdehart4684]

I want one

[@yori4666]

Thanks for the info. Good job. Looking for something to take camping. Into every life a drop of Karen must fall. 73

You should have told the police you were testing a sonic weapon.

[@piotrbienkowski1095]

or a portable HAARP kit to cause tornadoes.

[@garyfields3672]

I bought one of these...It was the biggesr P.OS. I ever got from More fu...king Junk. Do yourself a favor and by the Chamelion Spider. A much better product.

[@dixiedog1179]

No I don't,,,understand,,,

[@HamRadioCrashCourse]

Lol ok.