|
New to Ham Radio?
My Profile
Community
Articles
Forums
News
Reviews
Friends Remembered
Speak Out
Strays
Survey Question
Operating
Contesting
DX Cluster Spots
Propagation
Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers
Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net
|
| Reviews Summary for Comet CHA250B |
|
Reviews: 53
|
Average rating: 3.3/5
|
MSRP: $469.00
|
Description: The Comet CHA250B broadband vertical antenna will amazingly cover 75/80 meters through 6 meters with no gaps! Transmit range is 3.5-57 MHz and receive range is 2-90 MHz. SWR <1.5:1. This 23.5 foot vertical requires no radials and weighs only 7.1 lbs. The antenna consists of five sections of aluminum tubing that slide into each other. The bottom section has the matching network built-in. Only two simple measurements are required during the easy assembly. It can handle 250 watts SSB and 125 watts FM. SO-239 input. Mounts on a 1 to 2 inch mast (not supplied). Rated for 67 MPH wind survival.
|
|
More info: http://www.cometantenna.com/products.php?CatID=1&famID=5&childID=6
|
|
You can
write your own review of the Comet CHA250B.
|
K3DAV
|
Rating: 4/5
|
Oct 6, 2008 14:50
|
Send this review to a friend
|
|
Not too shabby
|
Time owned: 0 to 3 months
|
If you are expecting the performance of a StepperIR or a quality cut dipole, then don't get this antenna. But if you are space restricted and want to cover HF, then this is the antenna for you. My only complaint was the outragous $400 price tag. It's a good antenna, but a price of around $175 would be more appropriate. Come on! It's a coil with 23.5 feet of aluminum tubing on top. There is probably about $40 woth of parts here.
And to all of you who tried this antenna and had very poor results, you either had something very, very, very wrong in your installation, or you were expecting way too much for what this antenna is. After all, why are 90% of these reviews for this antenna all good if it's such a horrible antenna? Think about it.
Mine is mounted on 20 feet of mast on the side of the house. I am running LMR-400 feedline all the way to the Icom IC-706MKIIG at 100W on HF.
I talked on 10 meters (28.450 USB) to a few friends about 30 miles away, and it worked very well. I am still a Tech license, so a friend who is a general helped me test the rest of HF.
Over the weekend we contacted a few contesters on 17m, 15m, and 20m from Texas and California, and I am near Harrisburg, Pennsylvania. The reports were good at best. But a couple of contacts to Brazil and Argentina on 20m told the story. The 2 operators gave us an S7 to S9 signal report.
40 meters was too busy with SW stations to even try, but the receive was great. 80 meters gave a few contacts from NY, NJ, VA, and TN. All with good reports of S9 or better.
This antenna is not designed for 160m, but the AT-180 tuner with my Icom 706MKIIG tuned it with no problem. I could hear well on 160m, and a guy in SC heard us but too weak to have a QSO.
By the way. The 6m coverage gives a great SWR accross the entire band, but the TX/RX signals were less than half of what I get with the Comet GP-15 6m, 2m, 70cm antenna. A friends 6m repeater 35 miles away is a 30dB signal on the GP-15, and only an S-7 with the CHA-250B. 6m is the only poor performance of this antenna.
As a general coverage receive antenna, the CHA-250B is superb in every way. Most SW stations were 30 to 60dB and steady. Even the AM broadcast band receives very well. I can also hear beacons in the LW band. I believe the CHA-250B has it's best gain from 40 to 20 meters. Our best contacts and strongest RX signals were in this range. But the roll-off in either direction was very little.
The TX SWR without the tuner is as advertised by Comet. 1.1 to 1.6 from 10 thru 40m. A little higher at 75m (1.8) but the tuner took it down to normal instantly.
For what it is, the CHA-250B works well. Very easy to assemble too. Had mine together in 10 minutes. And the construction looks heavy duty enough to last. It is well put together.
You can see photos of the installation on my weebsite... http://k3dav.spaces.live.com
I recomend the Comet CHA-250B to any ham that is space restricted like me and want to have some fun on HF. I will be back with an updated review after a good workout with the new antenna.
|
|
KC9LCC
|
Rating: 5/5
|
Sep 19, 2008 19:02
|
Send this review to a friend
|
|
2nd review
|
Time owned: more than 12 months
|
|
I wrote a review a year or so ago. I have since had the opportunity to use the antenna more. I run a run a Yaesu 897d with tuner at 100 watts. I upgraded to a general class license in may. I have made contacts with Eastern Europe to Alaska using this antenna on 100 watts. Great one for the money. Also I had to move it to a new place after the initial setup due to sale of the house. Works great and would recommend this to anyone who is interested.
|
|
WM3L
|
Rating: 5/5
|
Jul 23, 2008 07:03
|
Send this review to a friend
|
|
WORKS WELL FOR ME
|
Time owned: 0 to 3 months
|
|
This will be my first review of this antenna and I will do another one at the 6 months mark. I have only been using this antenna for a week but since I put it up with base at about 18 feet off the back roof I have had no problem working anything I can hear. I have made 27 contacts in about 2 hours total of casual operating time. Contacts made were on 6, 10, 15, 20, and 40 meters. I have not really tried it out on 80 meters yet. SWR is flat 1-1 across all the bands from 80 to 6. It is a compromise antenna and if you have the space and desire to put up another vertical with as many radials as you can then go for it. For me that was not possible and this antenna is low profile, keeps the XYL happy, and makes me happy with being able to work whatever I hear usually with 5-9 and 15 to 20 over results. I understand the comments made by some on here but this compromise antenna works for me.
|
|
KE4PTM
|
Rating: 3/5
|
Apr 12, 2008 19:01
|
Send this review to a friend
|
|
Pick your battles....
|
Time owned: 3 to 6 months
|
The CHA-250Bx vertical from Comet is a decent vertical antenna for 20m and up. In fact, it works very well on 15m as I have worked most of S.America on it using only 100W. With a tuner you can go down to 160m but don't expect much. It is a surprisingly good receive antenna and will pick up everything from LW to UHF and I've had great success on MW/BCB piping it into a Misek phasing box with an aircore loop (gotta pad down the Comet about 10dB here for it to fly).
I have mine up 20' fed with LMR-400 and have a substantial ground sytem. I like the looks and lightness of the thing but am a bit perplexed as to why just a light wind storm in February put kinks into the top two sections. Comet replaced them free of charge and only required that I submit a pic of the antenna as proof.
The older models are prone to bending, especially if you have it on a mast that might whip the thing when exposed to 40+ mph gusts.
Don't get your hopes up for 40 and 80 meters although it will get out and you can make contacts. It doesn't compete even with a very low height dipole on these lower bands though there are times when it might receive better.
The antenna is not really worth the money for a location where you have wire or rotatable dipoles as alternatives.
If Comet optimized the CHA250 for 40m and higher, beefed it up for more power, and sold it for around $325....it would be a real winner.
|
|
W5WSS
|
Rating: 5/5
|
Apr 9, 2008 13:50
|
Send this review to a friend
|
|
a performance report
|
Time owned: more than 12 months
|
|
I operated in the recent CQ wpx contest using the Comet with non conductive support poles and rope the antenna base was at a low height of only 20' lashed to the cabin balcony. A temporary installation indeed. The extent of my participation was a total of 6 hours so I do not qualify to send my log to CQ. Anyway I used 100 watts pep power and the results were 172 contacts. One was with nh6p on 40. Considering that the majority of the time I operated the bands were insanly crowded,(3khz qrm was much stronger than my signal) I am ever more impressed with the Comet vertical. Later During the 4:00am to 6:00 am cst. early morning I listened to zl's and vk's on 40 at S-9 signal strength and s-0 noise level! One in particular called qrz contest repeatedly during the time frame...he made zero contacts,he took no calls yet his signal here was 599. So I think we can become used to our average height horizontal antennas propensities that better hear a different layer of signals than a vertical polarised radon or vice/versa! And more often than not some mistakenly use that as a comparator. The same can be said that the vertical hears better a certain layer of vertically polarised signals(DX) so take your pick! Just a thought When making antenna comparisons we should not compare the horizontal dipole to a vertical radon during a propogation mode that favors the horizontal polarity whether it be a dipole or a beam etc. So you may be asking how do you know when that is the absolute case? There are no simple,absolute answers... I can speculate indefinitely such as(horizontal antenna height and the relationship that is intrinsic to ground proximity as it pertains to its lobe formation, focal points of toa resulting in strong signals yet short distance hops(nvis)etc. So why the vk was S-9 here on my Comet yet for 2 hours he replied to zero calls? The answer is found over time with experience of using your antenna. Careful..when comparing the vertical to a horizontal radiator via skywave remeber that the vertical has a better propensity to DX due to low toa not <800 mile hops using high toa nvis. I am just reporting what I accomplished while using the vertical during a contest environment...the antenna works good. Regards w5wss 73
|
|
KC9JAR
|
Rating: 5/5
|
Apr 7, 2008 20:30
|
Send this review to a friend
|
|
very good performance
|
Time owned: more than 12 months
|
|
This vertical operates very well. I am very pleased with its performance. I have this antenna mounted on a telescopic mast. The base of the antenna is 27 feet above ground and 2 feet above my roof line. I have QSOs all over North America also Canada, Mexico Central America plus DX in South America, Western Europe, Caribbean and I expect to make more DX QSOs to other parts of the world. I would recommend this vertical antenna to anyone who's looking for a stealth operation or a light weight antenna that's roof mounted or on a balcony a deck or another stealth application. Because of its light weight you can use your imagination.I will do a another review in a few months.
|
|
G8JNJ
|
Rating: 3/5
|
Mar 13, 2008 04:58
|
Send this review to a friend
|
|
Bad Press ?
|
Time owned: 0 to 3 months
|
OK, first a confession – I don’t own a CHA-250 and I’m in no way connected to Comet or any of its dealers or agents.
However I have been experimenting with similar designs, have exchanged e-mails with several users (mainly people who have reported poor experiences with this antenna in this review section) and have built and tested several versions. So I think I have a fairly good idea of its performance.
The reviews of this antenna are either good or bad with not much in between, and I can’t help but feel that most of the bad press is simply down to unrealistic expectations or unfortunate installation conditions.
First this antenna is a compromise between performance and broadband operation. So it will not compare well against beam antennas at 100ft on the HF bands, or long wires and loops on the LF bands (also due to lack of NVIS coverage). If however comparisons were made against a similar length radiating element with an auto-tuner at the feed point, it would be within a few dB on most bands (except 3.6MHz where it would be about 6 to 8 dB down)
Unfortunately Comet give very poor advice about how to install the antenna, despite the claim that it needs no radials or counterpoise; this is not true, as radiation from the coax outer screen provides this function in part. I have modelled the design in EZNEC and found that in a typical installation, where the antenna is mounted on a 15-20m high conductive pole which is grounded, most of the radiated energy just heats the sky. Using a non-conductive or insulated mounting pole and adding some raised counterpoise wires can lower the angle of radiation and make a huge difference.
You can read about my findings here
http://g8jnj.webs.com/cometcha250b.htm
Or try building an optimised version
http://g8jnj.webs.com/broadbandhfvertical.htm
|
|
N7SSB
|
Rating: 5/5
|
Feb 2, 2008 15:03
|
Send this review to a friend
|
|
VERY STRANGE
|
Time owned: 3 to 6 months
|
VERY STRANGE THE MIX OF REVIEWS ON THIS ANT.
I HAVE HAD MINE ABOUT 6 MONTHS AND I AM IMPRESSED WITH IT TOTALLY.
IT IS MOUNTED AT 25 FT TO BASE OF ANT ON A CHIMNEY MOUNT.
I DONT EVEN HAVE A GROUND WIRE ATTACHED ETC.
I HAVE MADE CONTACTS HERE FROM ARIZONA TO NC, NY, AND ALL NORTH AND IN BETWEEN ON ALL BANDS.
DONT NEED TO USE THE INTERNAL TUNER ON MY PRO III.
EASY TO ASSEMBLE AS WELL, I WOULD RECCOMEND THAT THOSE THAT GAVE IT A 0/5 CHECK ALL CONNECTIONS AND CO-AX ETC. NOW,I WAITED FIRST TO BUY MINE DUE TO ANOTHER LOCAL HAM BOUGHT ONE FIRST AND I WAITED TO SEE HOW HIS DID AND IT WAS ONLY 15FT TO BASE MOUNT AND I WAS IMPRESSED WITH HIS AS WELL FIRST. AND SO IS HE.
|
|
VK5ZDB
|
Rating: 3/5
|
Jan 24, 2008 03:01
|
Send this review to a friend
|
|
Average for what it is.
|
Time owned: 3 to 6 months
|
I purchased this as my secondary antenna. For what it is (i.e. a broadband vertical antenna) the performance seems about average. It's never going to be as good as a resonant dipole. The construction quality appears to be very good. The unit is solid and has stood up to everything nature has to offer (so far). I have it mounted at about 8m and fed with RG-213 to my IC-7400.
Having said that, mine failed after 4 months. This turned out to be due to corrosion on the ground wire to the coax socket. To satisfy my curiosity, I decided to attempt repair rather than resort to the warranty. For those that want to know what's inside, the details can be found here: http://www.vk5zdb.com/cha250bxii.pdf
73's
Iain
|
|
KD4DWP
|
Rating: 0/5
|
Jan 15, 2008 23:16
|
Send this review to a friend
|
|
Does not work at all.
|
Time owned: 0 to 3 months
|
|
I Installed this antenna about 30 feet off of the ground. Observed 1.5 or less swrs from 14-28 MHZ. Heard some hams on 20, 17, and 10 meters. Could not work any of them. Comparing this to an IMAX 2000 at about the same height. I can load the IMAX from 17-10 meters. Talked to 4 hams and noticed from 1 gentleman 7-9 s units. Switched to the Comet and he went down to 0-1 S unit. That is just not acceptable to me. Returned to store. Either this antenna was a lemon or just does not work at all. Stay away from! I am in the process of getting my money back and will update this review. I did check and double check all connections. That did not help. Rig used was an Icom 746 non Pro. Thank you.
|
|
If you have any questions, problems, or suggestions about Reviews,
please email your Reviews Manager.
|
|
|
