| KC8ULE |
Rating:  |
2006-02-11 | |
| More than expected! |
Time Owned: 0 to 3 months. |
| Just had the Cobra Ultralight (Senior) up for a few days, but I am very impressed with construction, packaging and performance. Joe very helpful with some pre-purchase questions. Went up very smoothly (considering I was tromping around the back yard in snowshoes). Lighter than expected but the wings have enough body and are slick enough to not get tangled in branches. Using the Unadilla 4:1 balun in a pretty flat inverted vee configuration. Tuned properly on all bands using the internal tuner in my Kenwood 570D first try. The rig hears much better than on my old wire antenna. Worked some decent DX the first day. Antennas tend to not work very well at my QTH (sand dune)but the Cobra certainly does. Works well enough that I've actually started thinking about orienting the antenna to work where I want, rather than where I can. Had more fun on the radio in the last few days than in the last several months. Go Cobra! |
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| KK6BS |
Rating: |
2006-02-09 | |
| Snakebite! |
Time Owned: 0 to 3 months. |
I wanted to throw in a few words of joy and satisfaction regarding this tremendous antenna. Under the evil oppression of C C and Rs, my mission was to get on 75 meters with a decent signal. I have about 75 feet between the only 2 support points, a coupla trees in the back yard on the top edge of a canyon wall which puts things up at the 50 foot level. For years I used a 40 meter dipole fed with 450 ohm ladder line and enjoyed spectacular results on 40 thru 6 meters. While the Cobra Lite Junior (73 feet) seemed to be a perfect solution, its folded design made me a bit concerned about losing performance on the higher bands compared to the previous antenna. I knew the Cobra would work…it was just a question of how well. I was not about to give anything up on the higher bands just to get on 75.
Please understand that the underlying theme of my HF station is “cheap and dirty.” With a $125 transceiver ( TS-680S), a $50 tuner (MFJ-949D), a $15 dynamic mic and a power supply I’ve had for 20 years, buying a Cobra was out of the question, hi hi. After ogling at one through the package at the local candy store along with checking out a wiring diagram on the net (Google “W4JOH”), I decided to home brew this beast. To my delight, the 3 conductor flat wire similar to what Joe uses on his product was as close as the local Radio Shack store. It’s sold as rotor cable and comes in rolls of 100 feet for 15 bucks each. You probably won’t see the stuff on display but very likely, they’ll have a few in the back room. It’s definitely on the RS website and has an ‘in stock’ indicator. The store closest to me had 3 rolls in-house.
For the insulators, some form of weather resistant, thick, flat plastic will do just fine. For mine, I took a laundry marker and hacksaw to an extra copy stand I had lying around the shack/studio, used to hold up printed text for my commercial voice-over biz. A small sacrifice for what would be a great addition to the station. And oh, so cheap and dirty! Joe’s version of this antenna has very excellent stress relief at the feed point and end insulators. I strongly suggest you follow his method, feeding the 3 wire ribbon through close-spaced double slots at each termination point.
Performance.
The Cobra was installed and ready for testing just as the sun was going down. I would have to wait until the next day to check 20 meters on up but 40 and 80 were exciting prospects. A quick spin thru 40M yielded the usual strong sigs from stations in the Midwest and middle East Coast. I knew some of the ops and am familiar with their signal levels. Noise level was the same as the 40 meter half wave, too. No problem here, working great. I noticed the tuning was very smooth and flat as a pancake. SWR bandwidth was better than the previous antenna….nice! Now, on to 75. Same thing tuning the antenna…smooth as silk, not touchy at all and dead flat 1:1. Dropped into 3913 and worked a guy on Prince Edward Island. I then had to change my pants. That’s a long way from San Diego. More contacts into Texas, New Jersey and Indiana with 5/7 to 5/9 reports. It would be a late night. The next morning, I checked the locals on 75M within 500 miles. The Cobra was comparable to full sized ½ wave antennas at nominal heights, running out to Arizona, Northern Cal and even Oregon. Testing on 20, 17, 15 and 10 meters over several days was a homerun. At least as good as the previous antenna and I suspect a tad better with some locations. There are a few local radio pals within ground wave coverage; I know how the other antenna compared to theirs while racing to ops back East. The Cobra was right there with the usual results. Regarding the feed line length, 100 feet was a bit much since the shack is on the second story of a tall home. All that was needed was about 35 feet. Flat on 75, 40 and 20 but 1.5:1 was the best I could get it on 17, 15 and 10m. Increased the feed line length to 50 feet and hit a sweet spot. Completely flat, 80 thru 6 meters. Bingo.
I love this antenna. Have fun with yours, whether you build it yourself or get one from Joe. Either way, you win!
JoJo, KK6BS
San Diego, CA
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| WA6YUL |
Rating: |
2006-01-30 | |
| Great Antenna, great support |
Time Owned: 0 to 3 months. |
After exchanging several emails with questions I ordered the Cobra Ultalite Senior. Arrived in a couple of days, much quicker than I expected.
After fighting uncooperative trees and weather I finally got it installed at 30 feet. Since it was longer than my lot I have a 90 degree bend on each end for about ten feet and then a vertical drop of about the same. I used the full 100 feet of ladder line with a 4:1 balun to my antenna switch and then about 75 feet of coax to my shack. The built in tuner in my TS-480 matches on every band 160 through 10. Also tried 6 meters and it matches fine. Doesn't work as good as my stacked loops on 6 but receives and transmit fine.
I bought this antenna to fill in the gaps my verticals and half squares shoot over and to have at least local 160 meter and 60 meter capability. It works great for that and seems to work ok on DX, too. My first contact was LU/N6OX in Ushuaia, Argentina on 20 meters. If you want an all band antenna this is the way to go.
Pete W6OP |
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| N7DDD |
Rating: |
2005-12-19 | |
| Excellent Product & Support |
Time Owned: 0 to 3 months. |
| I acquired and installed the Cobra Ultralite Jr. and am delighted with it's performance. It works as advertised and is indeed rugged. My installation was in my back yard which we leave "natural" to blend with the greenway that connects to a 700 acre park. It was very difficult to string the antenna support lines due to the very dense tree limbs and brush. Consequently, I ended up "tugging" on the antenna a great deal more than I intended. It worked as advertised and has already survived an ice storm. Also, I received very timely and helpful responses to my pre-purchase questions. You should be VERY happy with this antenna. |
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| K1DRM |
Rating: |
2005-12-17 | |
| Fantastic antenna! |
Time Owned: 0 to 3 months. |
| My W9INN MPD-5 dipole was brought down by a tree that fell victim to a bad ice storm so I was looking for a replacement dipole that coved 10m to 80m. The Cobra UltraLite Junior is great. My first contact was in Senegal and the antenna is only up 25'. I'm glad I chose this antenna. |
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| KB1JZU |
Rating: |
2005-11-29 | |
| Antenna Good (4) Reviews Misleading (0) |
Time Owned: 0 to 3 months. |
I purchased the ‘long version’ of this antenna for installation at a second QTH in the mountains of Maine which ‘ate’ most dipoles and G5RVs in 6-8 months. It appears to be well built, and I’ll let you know in the spring how it held up. The installation is on the side of Sugarloaf Mountain at 1500 ft elevation. It is up as a flat top around 45 feet with a slight slope and possible slight imbalance (40 feet on one end, 50 feet on the other). Supported in the center, with pulleys/weights on both ends, the ladder line leaves at 90 degrees for about 40 feet and then goes to a 4:1 W9INN balun under my porch well clear of any metal or obstacle. I have an excellent perimeter ground at that point and 10 feet of coax takes it to the operating position.
It took some help from Joe W1JEK initially with the first install but he responded very quickly and provided some replacement hardware.
Now the fun part! After three weekends and a lot of measuring and trimming you have to realize that this antenna is basically a balanced line, center fed dipole with a few extra resonance points. If you install this as a plug and play, and can use your transceiver tuner on all bands out of the box, then you are very lucky or have a 50 ohm resistor shorted across the balun!
Out of the box my TS2000 would only tune 80, 17, 12, & 10. Other bands (160, 40, 20, & 15) had SWRs running form 6.9 to 10.3. The result was that I needed a broad band tuner. I picked up a LDG 200Pro and tried again.
This time with my trusty MFJ 259 I trimmed/lengthened the ladder line in five feet (then 1 foot) increments. I will be happy to provide the results on a spreadsheet to anyone who wants them (@arrl.net). Surprise! Surprise! The impedance & SWR profiles across all the HF Ham bands(160-6) change significantly with length changes. I settled on 82 feet which resulted in a SWR range of 1.8 to 8.8 with all my normal operations under a 7.3 SWR on all bands.
Next surprise, the LDG Autotuner tuned everything except 160 Meter. It would only tune 1.97 to 2.0MHZ (probably since the Cobra has a resonant point at 2.06Mhz) Calls to both LDG & MFJ confirmed the autotuners are optimized to the center bands and have marginal flexibility on the fringes of the specify frequency range. Good grief.
No I am not going to a manual tuner. At least not until an amp comes into play.
Bottom line: The antenna is fine, but the expectations and ease of installation will vary significantly. I’ve activated a number of antennas in the past year (LPAs, Verticals, Staggard tuned Dipoles, G5RV, etc) This has been the most challenging (and fun HI HI).
Bob KB1JZU
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| W7TOC |
Rating: |
2005-11-21 | |
| UltraLite Junior |
Time Owned: 3 to 6 months. |
My first Cobra UltraLite Junior had a problem, which I could not find with my MFJ antenna analyzer. I called Joe Kramas, K1JEK who makes them and he was so nice. We were not able to problem solve the issue over the phone so he had me send it back. He promptly sent me another antenna which works perfectly. It tunes flat as a board from 10-80 meters. This is one great performing antenna, even though I do not have the space to set it up properly (small lot). It is so great to be able to tune on ANY part of the band and have a dead flat SWR.
Not all companies stand behind their products, like LDG for example. I was one of the unlucky ones to get a defective tuner, they were hostile and refused to fix it or make it right. So I really appreciate business men like Joe who care about making their customers happy. I have to say that I could not have asked for any better or more pleasant service. I highly recommend purchasing this companies product. Thanks Joe, I wish more companies in the ham radio industry had your integrity!
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| KK8B |
Rating: |
2005-08-19 | |
| very pleased |
Time Owned: 0 to 3 months. |
| I installed the ultralite 140 ft. senior at 25ft, used all 100ft of ladder line to 4 to 1 balun outside,then coax inside to radio. All bands tune easy using radios tuner.80/75 has complete coverage with low swr, a bit higher on 40 , but not out of range of my ts-2000s tuner,looking forward to working 160 this winter, im pleased with this product. |
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| KC2GWK |
Rating: |
2005-08-15 | |
| Buyer Beware |
Time Owned: 0 to 3 months. |
I have read all these reviews and I am wondering if they are about the same antenna I purchased. I bought the junior antenna and followed the directions for installation. The antenna is 50ft in the air in a flat top configuration. When I hooked it up to my radio, it would not tune on segments of certain bands, most noticeably 75/80. I called Joe to get some help and was told that my radio, which has a built in tuner would not accept more than a certain level of SWR and was told to trim the twinlead back 19 feet. I did and while some of the problem was solved, I continued to have problems on 75/80. I emailed Joe to ask for further assistance and was told that the next step was to buy a tuner extender (price $60). Not the answer I wanted to hear. If in fact this kind of problem exists with radios that have built in tuners, prospective buyers should know that in advance. For the cost of the antenna and now the tuner extender, I could have bought a better antenna, which is what I intend to do. I am not pleased with this antenna and would not recommend it especially to someone who has a radio with a built in tuner and intends to use it. Additionaly, the performance on 40 seems to be very good. It seems to under perform on 20. Can’t tell on 75/80 because I can’t tune the band.
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| K0CWO |
Rating: |
2005-04-27 | |
| Works as advertised |
Time Owned: 0 to 3 months. |
| I installed the Cobra Ultralight Senior between the tripod on the roof of my house and a tree in the back yard this weekend. It runs northwest to southeast, away from any obstacles, 30 feet above the ground. As recommended, I installed the full 100 feet of ladder line all the way into the shack and connected it to my Palstar AT1500BAL antenna tuner. The antenna tuned easily 160-20 meters. I did not check to see if it would tune 17-10 meters because I use a different antenna for those bands. I reversed the feed line leads on several frequencies after tune up and the SWR did not change, indicating that the antenna and feed line present a balanced load to the tuner. The performance on 75, 40, and 20 meters is identical to the 250 foot ladder line fed dipole I was using before. The reason why I switched to this antenna from my 250 foot dipole is because I had trouble getting a reasonable match on 160 meters with that antenna because of an unbalanced situation with it running close to buildings and through trees due to its size. I am sure the Cobra Ultrlight Senior will not perform as well as a full size 160 meter antenna, but I reliably worked several stations out to the 600 to 700 mile range using 100 watts during noisy band conditions. The build quality of the antenna is excellent. Although the maximum power is rated at 1KW, the owner informed me that the antenna will take legal limit on all bands except 160 meters. If you are looking for antenna that will work like a regular doublet on 80-10 meters, and with somewhat less performance on 160, I can highly recommend this product. |
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