The Comet CHA 250-B Vertical HF Antenna

Taking a look at this dynamic HF Vertical antenna from Comet. It's not perfect, but it's better than you would think.

[@K4SRF]

The Comet CHA 250-B performs better than expected. If you have limited space, this antenna may be an option you might want to explore.

[@davidboswell3544]

Hhh

[@Joe-629]

Question, what paint were you going to use? Looking for a paint that I can use for mine to keep it as invisible as possible.

[@K4SRF]

@@Joe-629 You can use any good exterior paint providing that it is free of any metals.

[@Joe-629]

@@K4SRF thanks!

[@NorthTXMountainbiker]

I've have the new model, the CHA250HD. It's been up about a month. It's mounted atop a 20 foot collapsible flagpole, and connected to my shack with 75 feet of RG-8X. Just before it enters the shack, it's connected through an Alpha Delta lightning arrestor. When I installed it, I got better than advertised SWR numbers everywhere except 80m, and since then I've been pretty pleased with it. I've been too busy to spend a lot of time on the air since then. Still, from my shack in northeast Texas, I've worked the Falkland Islands, Madiera Islands, Chile, Belgium, and Great Britain, Vancouver BC, and of course a lot of US stations. The very distant stations gave me 56,57 signal reports, so I'm not booming across the Atlantic! But I'm only running 100W, so I've been pretty pleased overall! But watching this video made me curious, and it's too cold to do anything else right now, so I just tested it again. For the version I have (CHA250HD) Comet claims less than 1.6 VSWR from 3.5Mhz to 57 Mhz (In other words, all HF bands including 80M). I did not test it at the antenna (cause that's 20 feet in the air, and it's cold out there). I tested it at the shack with a Comet CAA-500Mark II. I tested the following bands: 80, 40, 30, 20, 17, 15, 10 and 6 meters. Somehow, I forgot 12m. On the voice portion of 80 meters, VSWR was 2.8 at 3.600Mhz, dropping to 1.9 at 3.750Mhz, and rising back up to 2.6 at 4.000 Mhz. It was higher than 2.8 in the CW portion of the band, but I don't do CW anymore, so that didn't concern me. But still, way above their claims of 1.6! On the other hand, all the other bands were well under their claimed VSWR! On 40m, the VSWR was 1.3 or less from 7.000 to 7.300 Mhz. 0n 30m, the VSWR was 1.3 from 10.100 to 10.150 Mhz On 20m, the VSWR was 1.2 from 14.000 to 14.350 Mhz On 17m, the VSWR was 1.2 or less from 18.068 to 18.168 Mhz On 15m, the VSWR was 1.2 at 21.000Mhz, and 1.1 at 21.450Mhz On 10M, the VSWR was 1.2 at 28.000Mhz, dropped to 1.1 at 28.350Mhz, and rose to 1.4 at 29.700Mhz On 6m, it was 1.3 at 50.000Mhz, dropped to 1.2 at 51.500Mhz, and climbed to 1.4 at 54.000Mhz. I'm a little disappointed with 80 meters, of course, but I'm very impressed with all the other bands. And even on 80, my radio seems to be able to tune it up without issue. I was under the impression the only difference between the current model and the previous one was that the new one replaced the last tubular section with a metal whip, to reduce wind resistance. But perhaps there's more differences that would account for the better results I got on 40m and up? When I first tested it, I didn't have the lightning arrestor in place. It seems to me that 80m was a little better then than now, but not significantly so. I wish I'd written the numbers down back then. But even with the rather poor numbers on 80, I'm happy with my antenna. It's easy to put up and take down if the wind kicks up, and doesn't need radials. Those were my two most important criteria. I think it's well worth considering if, like me, you want a vertical antenna but don't want to mess with radials.

[@joeunderbrink6056]

Thanks for this review. I'm seriously considering this antenna as I live in a HOA restricted neighborhood, have a small yard and inadequate space for proper ground radials.

[@bertgarcia5969]

I've use this antenna for more than 10 years on my RV. It assembles in a few minutes and is mounted on the rear ladder using the Flagpole Buddy mounts. It's only installed when parked, of course. I have no problem working stations in the USA, Europe, and South America on multiple bands. It's a compromise antenna, but for RVing where campgrounds don't permit radials or wire antennas, it works well. I use 50 feet of coax and have a low SWR on all bands.

[@Jail-Left-Wing-Traitors]

Interesting..I am in the same situation here in the UK I intend to use it in my motorhome..why do you use 50 ft of coax ? Thanks

[@Jail-Left-Wing-Traitors]

Does the 50ft of coax act as A Baulun or UnUn maybe

[@michaeldavidheit]

Thank you very much for the video sir. I am going to buy a vertical for my ham shack after using an OCFD and now an end fed dipole for the last 11 years ... and lost both antennas due to snow loads and ice bringing down trees nearby. I have about 1 1/2 acres of land but lots of very tall spruce and birch trees to factor in so a vertical seems to me the better type to work with. I may still keep the end fed up for some use but if the vertical does good maybe keep the OCFD and the end fed for EMCOM use. I should mention I live in North Pole, Alaska and the 9 month lng winters here can be brutal with lots of ice & snow loads. Winds for the most part aren't going to be a factor as much as the ice and snow felling adjacent trees ... so cutting up some more firewood is in the near future too.

[@user-cg7uw9uh6n]

Nice video thanks. This as the highest swr readings iv come across. Most operators report swr of 1.3 hf and 6m

[@K4SRF]

Yes it did. After I raised it and checked again, it dropped.

[@user-cg7uw9uh6n]

@@K4SRF iv considered this antenna for many year's

[@rudysmachine1]

Cable length is very important on the SWR that an endfed antenna will exhibit. Usually 50 to 75ft of good Lmr 400 should bring the SWR to the manufacturers advertised SWR curves.

[@K4SRF]

I am using brand new LMR 400 @ 75'. But thanks though. I'll keep checking.

[@ddc0d3r]

Thanks for the review. I just got mine and plan on mounting it soon. I'm also plagued by an HOA, have no idea how they'll react but for now I'm keeping the mounting pole to 10 feet to start. Maybe later I'll increase it. Great job on this review, 73, W2HOT.

[@K4SRF]

My HOA is somewhat lenient. Good luck. You can always try by raising the pole a few feet every month. :-)

[@calthomas3]

Hi K4SRF - I'm glad you like it, I used it also in here in FL worked Seattle and Madrid on 20 SSB - was ground mounted on a 124' deep well pipe and also about 500' of radials on the well pipe to. For me the compromises were not the prob--- well they were... Others have described this antenna as a dummy load with a whip on it :-) .. That to me is closer to the truth - especially after it quit on me after about 2 years. (It was given to me so it may have had several years on it -b bout didn't look it) - Out of curiosity I did surgery on it - and you an find out the innards on line too. It has 2 toroid's and the failure for me (using 100w) as condensation that corroded big time the connections to be unusable. It could have been ressurrected but I wanted to look elsewhere. Still, want to give you kudos for your presentation. Cheers 'n 73 Cal Mim, FL

[@K4SRF]

Mine got destroyed after an unexpected high-wind storm. I was at work and couldn't prevent this. So, I took mine down and have since preplaced it with a DX Commander Classic. I still have the load and may cut it open myself.

[@EdzashedFudwinkle]

Dipole would only be around 10m per leg, inverted V ideal for small locations.

[@artdodd2932]

I had one worked the Dexpedition in the Congo on 20 M. I had it up at to feet 15 ft behind my aluminum sided house. Not the installation comet recommended but I had a ball with it.

[@buzzsah]

I was given one but not have a chance to install it. I was told try to keep free from trees, try to keep the base above the trees, or try to keep 70-75 ft from any trees, building. This was told to me by an old-timer that tried it at 25ft from the base, and 30-35 ft from trees, His swr'r were 1.7 - 2.4 across the HF bands, he then installed it on a 50 ft free stand tower and the swr's on the highest are 1.9, and as low as 1.4.

[@EdzashedFudwinkle]

Signa EuroComm Se-80x vertical for the past 15/18mths, its worked as expected. Put a 64ft Efhw out the back window 22ft up pointing SW, broadside is amazing, and Cornwall,France,Italy,Serbia all 9^5's till gone 01.00hrs the Fathers Day. Have a great Sundays. 73's 👋

[@K4SRF]

Great!

[@stevenlawhon3695]

It might help those high swr readings if you multiply the antenna length x vel. factor=coax lenth to achieve a 50 ohm match.

[@stevenlawhon3695]

Use the lowest freq, to see how much rg213 you will need.

[@kirwanjohn101]

Very honest review. Thank you

[@frankvandornis4373]

Great T-shirt!!! Yes, I know what it means.

[@austieoutdoors9763]

yes i have just got the comet as i passed my foundation may 1st 2021 and as i was using the uk antennas end fed i thought i might get a vertival of some sort so i went and bought the comet cha250 i put it up in the garden about 4ft and my swr is 1.0 on 80m 1.0 40m 2.3 on 20m 1,0 on 17m and 10m its is 1.0 so its flat on all bands except 20m. all thou it is abit high on 20 it still works well on there stations i don,t hear on the end fed i can on the comet. m7byf ste in skelmersdale england. oh i noticed you have it high try it at ground level then check your swr because when i had it errected high my swr was a ;little high

[@lonewolfeire9176]

you are spot on..this antenna is designed to work best ground mounted as you have.....similar set up as myself and have no problems with swr....1.7 on 20m is the highest.

[@austieoutdoors9763]

@@lonewolfeire9176 yes that's a good swr on there mate its probably the best your gunna get on there by speaking to people who have the antenna

[@michaeldavidheit]

Thank you for this analysis; I'm planning to buy this antenna and wanted some good information on it and you hit the nail n that. Are you still using this antenna? How do you like it? If I buy one it will be my primary antenna as I don't have anything else except for my Buddie pole set up. I've had dipoles up here where I live in North Pole but the ice and snow really kill's them when it gets heavy. Not much wind factor, but it does get cold and the ice & snow doesn't malt off until mid-April or so.

[@GordonHudson]

I think I know why the VSWR changes when you mount the antenna. Apart from the orientation to ground, the pole is off centre feeding it. Because its voltage driven this should really make no difference, but in reality it will affect it quite a bit. I would be tempted to put a choke in the coax a quarter wave back from the antenna on the band youneed it most in tune on, or better still, mover it up and down and see what difference it makes.

[@RaulMendezfritz269]

Using a common mode choke (7-9 turns, 6-9" diameter) on your coax about 1ft below the connection to the transformer at the antennha's base will virtually solve your SWR issues.

[@EdzashedFudwinkle]

Using a Fare-Rite 43 toroid ring 6/9 turns onto a 40/50cm patch lead. Equivalent would be several coils with the coax beneath the a Tennant feeder point.

[@alvarogaitan2529]

thanks very much terrific job thanks from kb2uew 73

[@TI2GBB]

Thanks for the video, it's very helpful!

[@K4SRF]

Glad it was helpful!

[@minnowpoo]

The Comet CHA 250-B don't need a UGLY BALUN I use the same but only on a 12ft pole all bands 1.5-3

[@lonewolfeire9176]

keep this antenna ground mounted.....will work at its premium.....but less effective at height. i have used my one many times set up on various locations on a drive on plate and never seen the swr to come close to 2.0. from flat swr to 1.7 on 20m, never tried it on 10m.....i cant complain on its performance.......as i said at the beginning.....use this antenna ground mounted, not at height...thats my experience with it....good luck and i enjoyed the video.

[@K4SRF]

Thanks for sharing

[@watkinssixtyfive7788]

I wonder if eliminating the coax choke at the feedpoint would improve the SWR, since it uses your coax shield as a counterpoise. Maybe some snap-on chokes placed further down the line would serve to define the counterpoise length and also keep RF out of your shack?

[@McCamerCoach]

Greetings. I purchased a new to me comet. The package did not include the paracord kit I do not see anything of it mentioned on the instruction kit. Can you tell me what the unit is called and what size is required. I will have to purchase I have a 30m telescopic with appropriate guy wiring

[@BBaldwin]

Got one, love it, but can’t hit the local 6 meter repeater. Fair warning- this antenna DOES NOT cover (on TX) the full 6 meter band, only up to 57mhz.

[@markw6549]

I get sick of watching so many reviews that show the technical specs but never show real world use .Show the antenna once up and painted,show it in use on your radio. Now that would be a real test.

[@K4SRF]

The price you pay for Carbon Fiber. I have seen similar Rohn masts going for about the same price.

[@rickmckee6698]

It has no radials because it uses the coax shield as a counterpoise which means the coax is part of the radiator! I had one and gave it away because a cheap piece of wire outperformed it!

[@DZX5000]

I am very surprised that many people have reported such poor performance from this antenna. I wonder what is the cause. I was literally going to pick one up today (sept 1 2022) from Toronto radio world but now I am holding off. I am currently using a horizontal wire 35 ft long going into a 9:1 box , I can get out and receive but very curious how my wire setup would compare to this antenna. Who knows. Anyways thanks for the review. 😂

[@rickmckee6698]

@@DZX5000 Your wire will outperform it, but even it can be improved. Don't buy into the "no radials, has low swr on all bands gimmick" This just means the losses are high. The thing has up to 6db loss on some bands and remember, just 3db loss is like losing half your power in the form of heat !

[@DZX5000]

@@rickmckee6698 thanks for the information

[@joearcuri3377]

i just picked up the CHA-250HD and was wondering if adding say an LDG 1:1 common mode choke / balun is a good idea since mine is mounted kind of like yours except it's only 20 AGL on a metal conduit and is close to my thermopump... any thoughts on the matter? 73

[@K4SRF]

You can try it. I don't have this antenna any longer, (got destroyed in a storm.) You used the term AGL; do you fly by chance? I have not heard this acronym used normally outside the aviation community.

[@FilipeJorgeSilva]

I do have a limited space and that's the reason why I bought one the problem is that this antenna is complete deaf, the SWR is good on all bands, except 80 meters, but if I can't listening nobody I can't transmit. So I decide to remove it from my roof.

[@rickeaton5288]

Well you say it's not rated for 80m? 3.5 - 50 covers the 80m band in my book. Also you have a very narrow 80m portion and it's adjusted at the top section where the twin collars are and you can't check SWR on this in Horizontal position then vertical and expect the same type of readings.

[@K4SRF]

Narrow on 80, but I did make some contacts.

[@rickeaton5288]

Yes that's why I said you have to look at the directions and adjust the top tube only for where you want to be on the band and tweak it for your set-up.

[@kd4hgr]

You stated this antenna does not cover the 80m band you might want to read the specs again as it says it does 6 - 80m ???

[@K4SRF]

Thanks. I'll check.

[@TEGEscalator]

Greetings from Belgium 73 👍

[@K4SRF]

Morning, Afternoon or Night back at you!

[@forgetyourlife]

Any chance mounting it to a long metal mast effects the swr?

[@K4SRF]

Yes. My SWR did lower significantly after mounting it to the mast.

[@RonBennett-lg8po]

I get 1.3-1.5:1 across all bands, running RG8 coax. 250 watts? You don’t need it. I have made contacts all over the US & Canada, as well as Europe on 100 watts or less. 35 ft above ground? I’m a little less than 3 feet AGL.

[@g.h.2800]

tnx, for the good information. 73!

[@K4SRF]

You are welcome!

[@TI2GBB]

Sr I see that you use a Pyramid power supply, how it works? it's a good Power supply? I see the reviews in eham website but it was not good and convincent the outputs of the people that have used that power supply ( I don't know why) thanks for your response!

[@K4SRF]

Personally, I have had no problem with this power supply. I do agree that the output terminal placements would be better if they were located at the rear of the unit instead of the front. Again, outside of this, I have had no problem with this power supply.

[@TI2GBB]

@@K4SRF Thanks for the feedback. I will buy one of these for my IC7300. Thanks a lot! 73s TI2GBB

[@K4SRF]

@@TI2GBB You are welcome.

[@ssubaihi]

Nice Intro

[@Aleziss]

I don't trust those wingnuts... are there lock washers for the wingnuts ? with the flexing and constant movement, I don't feel these will stay securely tighten... specially the last section where those little two screws only pinch the last section, with flexing, that could easily loosen those tiny screws... Will you leave it up all the time ? I was wondering if you had planned to tape all the joints in the antenna, with those wingnuts, it will be difficult to tape the joins...

[@K4SRF]

Yes, the wingnuts do have lock washers. I tighten them a little beyond finger tight and then found them a bit difficult to loosen. I think they will last. No, I didn't tape the joints, even though I had considered it, but the joints intersect and join in such a manner that they should remain water / weather resistant. Though I plan on leaving it up all the time, I do plan to lower it in about a month or so to check out the connections.

[@daveN2MXX]

You can't ever check a vertical antenna's SWR with it parallel to (and only inches from) the ground. Also, a 1ft length of coax will have negligible impact on power/swr at HF frequencies, regardless of the type of coax...so I don't understand that part of the video. Also, you show at the end of the video that the SWR goes up when mounted 50ft up...often the loss in 50ft of coax artificially reduces the measured swr, so that is a surprising finding.

[@K4SRF]

It turned out that there were two factors I didn't discover until after the video was posted. I had both a bad connector plus a hidden cut in the coax. Once replaced all was well. UNTIL, Hurricane Sally in 2020 destroyed this antenna.

[@daveN2MXX]

@@K4SRF thanks for your response, and sorry for your antenna loss during the hurricane! 73 de N2MXX

[@rttakezo2000]

Does what it claims if installed as instructed

[@alvarogaitan2529]

thanks terrific review From kb2uew

[@ziptie7112]

dont know your location in Florida, I am in coastal Charlotte county...N. of Ft Myers....I am afraid if I install 20 - 30 ft above ground, the first good tropical storm will take it. Wonder where you are and what has been your experience?

[@K4SRF]

NW Panhandle. I have lost an antenna due to a storm, (Sally.) Problem was, we were told the storm was going away from us so I, (as well as others) were not prepared. This won't happen again!

[@forgetyourlife]

does 35 foot minimum for max performance mean the top or bottom of the antenna? And will it get DX or only regional contacts?

[@K4SRF]

Per Comet, they recommended a mounting height 8 to 10 feet from base of the antenna to ground. Best performance is realized when installed 33 feet above ground. Below 33 feet, regional contacts are most likely, but with 33 feet and above, DX is possible. Of course, depending on signal propagation. Personally, I have not made any contacts outside of the USA, (not including Canada) yet, but I have only had this antenna up for a couple of days now, (at the time of this posting.)

[@forgetyourlife]

K4SRF thanks. Have you tried 80m yet? It rated to go that low.

[@K4SRF]

@@forgetyourlife Not yet. Probably this weekend.

[@forgetyourlife]

@@K4SRF So how is it on 80? NVIS only I suppose and have you made any DX yet on 20 or 17?

[@ssubaihi]

i am interested in Receive Mode ... How does it perform ? is it Noisy ?

[@K4SRF]

Not really that noisy.

[@raydavidsonm0ray.777]

I have 1 of these rubbish aerials too. What they don't tell you in the instructions is, , , that if yo connect a piece of wire to the out side of the SO239 connector, the same length as the antenna, , ,& let it drop straight down, it will work much better.

[@calthomas3]

whoops another comment -- the condensation wa from heat dissapation from the torroids in this FL environment - finally taking it down.

[@ChaplainDaveSparks]

Another single element antenna with a *_”magic black box”_* at the bottom that matches all bands. What sort of electronic wizardry might be in that box? (Other than a resin-potted dummy load?) I would think that by now someone would have reverse-engineered this and similar antennas and come up with a DIY clone … Is it a _”random wire monopole”?_ *73 de AF6AS*

[@hrickwood]

Hi, This is Rick WH2O on Guam Island. Found your CHA250 submission interesting (and for me timely). I am searching for an antenna and was considering several including CHA250B and the Diamond BB7V as well as others. I would like to query you regarding my search and your experience. I can do it on this channel or on email (QRZ or other) if you are okay with either. 73

[@K4SRF]

Either would be fine.

[@forgetyourlife]

I noticed your monitor jumped from the desk to the wall by the end of the video :)

[@K4SRF]

This video took a few weeks and I did some re-arranging. Good catch!

[@miltonderezende7906]

I HAVE A CHA 250 WITH 6 RADIALS OF 5 METERS EACH MOUNTED TO THE GROUND LEVEL. IT IS A GOOD ANTENNA BUT VERY BAD IN 40 METERS

[@K4SRF]

I have found both 40 and 80 meters to be the "problem children" in HF.

[@snuitje100]

I have had one CHA250 in for repair. After much difficulty to get it disassembled i found that water ingres was the culprit. Anyway after having the chance to examine i would strongly advice to leave this piece of shit in the shop window since you can hardly call it a radiator. A dummy load would be a better description for it.👎👎😡

[@DZX5000]

I’m reading all these reviews because I was about to buy one today but I am now holding off , thx for the review 😂

[@letsgo4629]

Hot mike at the beginning there... my poor ears

[@AliReza-zx8km]

Nice....

[@cobrasvt347]

What's that beautiful key you have there ?

[@K4SRF]

What key are you speaking of?

[@matthewtaylor3301]

I refuse to live anywhere with a HOA.

[@thom3124]

I bought one and it never worked. This thing is junk. A friend of mine bought one and it did not work either.

[@billcawthorne3114]

What is the significance of your shirt?

[@K4SRF]

It shows "1 asterisk" which translated means, "One Ass to Risk". This shirt also has a blue line. This shirt is meant to show support for the law enforcement men and women who risk their lives every day on the streets.

[@spuddyspud8178]

Your SwR is way higher than what my antenna is.you sure your antenna isn't faulty

[@K4SRF]

No. It settled down once the antenna was raised.

[@paulhastings3109]

Check out DX COMMANDER 10-40 mts will do 30 mts. 80 in L

[@Porco_Utah]

I have one of this, it is good antenna above 7Mhz. receive pretty well even at AM broadcast. however, for particular band, my fiber glass 33 ft collapsible flag pole with wire attached, and Automatic Antenna tuner at ground level, and decent ground out perform CH-250 ANT. so I don't use it anymore. anybody want it can have mine. AG6JU

[@Wynterspop]

If you still have it, I'm interested. What do you want for it?

[@Porco_Utah]

@@Wynterspop long gone.

[@M-P-X]

That's a lot of money for a basically cheap 10 meter 5/8 antenna.

[@skipstover8867]

yea screw the yard LOL radio first

[@niftyfiftycampingadventure795]

Ermmm No... Rolling with a trapped dipole...Thx for the upload..

[@vk5cjc]

Radiator around matching transformer dissipates heat loss! for God's sake! T2FD is a much better alternative fed by 450 Ohms line..

[@blueharley2]

broken audio

[@K4SRF]

I found this out in post. Nothing I could do at that time.

[@camrodger8638]

I have found this antenna to produce a very high noise floor. I’ve compared it to a long wire I two different locations several km’s apart with similar results. A borderline useless antenna.

[@pietrogazzera5733]

For me, waste of money, waste of time. It's a quite perfect dummy load!

[@ziptie7112]

Hope you find out what your problem is as it is a great end fed antenna if installed properly

[@vk5cjc]

This antenna is nothing more than a"Perfect dummy load - cloud warmer with 16:1 transformer" .. I have a video of the matching unit temps when 200W CW is applied at 7MC- guys wake up ! watch this .. message from Tele Radio transmissions engineer ,educated in 1970's. www.vk5zd.com/CHA250/CHA250.aspx

[@brian.7966]

I hate it, a load of crap that doesn't work.

[@K4SRF]

I was able to have QSO's over 1,200 miles distant and was told I was coming in 59.

[@paulkazjack]

@Johnny Rebellion Ft8 is not ham radio.