| N7WLF |
Rating:  |
2016-04-14 | |
| Needs Maintenance Yearly. |
Time Owned: 3 to 6 months. |
My DX-77 was given to me in non-working order. The ham I got it from owned it 5-6 years and in that time it slowly got to be a 10 meter mono-band vertical. I brought it home and set it up and sure enough it would only work 10 meters. If you shook it hard 12 and 15 meters would work intermittently. The trap coil on the 17,20, and 30 meters needed to be re-wound as the insulation on the magnet wire was long gone with the Arizona sun and heat. I rewound the coils on 17, 20, and 30 meter traps. Replaced the fiberglass tube insulators to fiberglass solid rod. Re-soldered all connections on the traps, and cleaned all of the joints and connections on this thing. About 8 hours worth of labor and $40.00 worth of #12 magnet wire and fiberglass rod and it works great mounted on a 6 foot mast in my rear yard. Its supposed to be a 7 band vertical 10-40m. I found mine also works well on the lower 2 MHZ of the 6 meter band. Mine is a 8 band vertical.
My on the air checks were "if I could hear them I could work them". Signals much stronger in most cases than my 10-80 OCF Dipole. Antennas need maintenance from time to time. |
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| VA3LUK |
Rating:  |
2012-06-06 | |
| waste of money |
Time Owned: more than 12 months. |
| If you want spent more time on your roof doing some repair but not on the radio, this antenna is for you. After a few months of use this crap I have to replace all capacitors because it burned on 800W PEP, than later antenna stop working on 18MHz, even technician from HG had no idea why. During the wet weather SWR jump from 1.2 to over 5 on 21MHz to 28MHz. This antenna must be guyed to survive wind with speed 60 km/h not MPH. So I replace this antenna for AV640 because I was tired to fix it on average every two weeks, So do not buy it if you LIKE MAKE MANY QSOs THAN TO BE ON THE ROOF! |
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| NB5VO |
Rating: |
2011-01-02 | |
| Poor quality and Over priced |
Time Owned: more than 12 months. |
I paid about $500 for this antenna. The quality control and design is so poor I don't know how anyone can rate this over a 1 star considering the price. The pieces did not fit together and for a couple of sections I had to buy a rat tail file and stick it on my drill to ream out the section it supposed to slide into. The fit was way out of tolerance and I had to ream it out quite a bit. The radial mount to the fiberglass would not clamp to the fiber section even if I bent the clamp section quite a bit and is still loose and drops to short out the bottom section. There is over 1/8" space between the fiberglass section and radial clamp making it impossible to mount the radials on the tube. I had to remove one entire radial and bend the bracket so it won't slide down and will still slide down when the wind blows.
The antenna is constructed of too thin aluminum in order for them to save money probably. Because of this the antenna bows, bends over, due to using thin aluminum tubing which cannot support the traps so antenna cannot stand erect and bends over quit a bit due to weight of the traps on the tubes.
I got no response from Hy Gain at all concerning these issues. I guess because they are out of business. Because of the bowing and poor engineering the SWR is not stable and changes when the slightest wind blows. It will not stand up to 60 MPH winds like they claim and appears to almost break when wind is about 10 MPH due to being extremly flimsy swaying back and forth in the wind like a whip.
The SWR is bad and impossible to adjust and has very narrow bandwidth. It does not tune 40 and 30 meters at all with my built in antenna tuner for the Yaesu. External tuner will tune to about 1.5-2.0 if wind is not blowing. The antenna was assembled exactly like the instructions said also. It works on lower bands with built in antenna tuner.
I got this because not many antennas have 30M. I am not sure why they charge so much and seems to be the most expensive vertical antenna on the market, more than some Yagi antennas. Hy Gain doesn't exist anymore so I guess that is the reason, and MFJ is famous for cheap stuff but prices are also cheap usually except for this piece of expensive garbage. I hope that they are not proud that this thing is made in the USA. |
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| K7NI |
Rating: |
2010-10-30 | |
| Performance 5 mechanical 3 |
Time Owned: more than 12 months. |
I have an early pre-MFJ DX77. I am happy with the performance of this antenna. It works very well for a trap vertical.
I did have a couple of issues. The first models did not include rain covers for the traps. This made it useless in the rain. I complained to Hy-Gain and they sent me free rain covers. I don't know why they didn't include them in the first place. The DX77 is very whippy. It has stayed up but has developed a bend at one of the connections. It still works fine but looks odd. |
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| AA6VB |
Rating: |
2008-07-08 | |
| Surprisingly Good Performer |
Time Owned: more than 12 months. |
I bought this antenna 12 years ago, put it up, and then promptly replaced it with a small beam. My beam crashed in a storm a few years ago, so up went the vertical. Frankly, I was not expecting much. The vertical performs surprisingly well, and I have been able to work the entire world with only 200 watts at the minimum of this sun spot cycle. If I can hear them, I can work them.
This antenna is no beam and does not perform as such. However, as a vertical, it works very well. In fact, surprisingly well. I would give it a 5 except that when the vertical gets wet, the resonant frequency shifts considerably, and back again when it dries out. Very annoying. Presumably the water affects the capacitance of the traps. Other than that, it works very well and I am quite happy with it, especially on 30 and 40 meters. The antenna is 29 feet tall, so the traps don't add much to the electrical length on the low bands which may contribute to its surprisingly good performance on 30 and 40 meters. A quarter wave on 40 meters is 32 feet, so this antenna is almost a quarter wave on 40. In the world of multi-band vertical antennas, this is a fine performer.
The quality is excellent, and the antenna has been through several winters and has held up very well mechanically, although this antenna was made about 12 years ago by Hy-Gain.
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Earlier 4-star review posted by AA6VB on 2007-02-09
I bought this antenna 10 years ago, put it up, and then promptly replaced it with a small beam. My beam recently crashed in a storm, so up went the vertical. Frankly, I was not expecting much. The vertical performs surprisingly well, and I have been able to work the entire world with only 500 watts. If I can hear them, I can work them. This is no beam and does not perform as such. However, as a vertical, it works very well. In fact, surprisingly well. I would give it a 5 except that when the vertical gets wet, the resonant frequency shifts considerably, and back again when it dries out. Very annoying. Presumably the water affects the capacitance of the traps. Other than that, it works very well and I am very happy with it, even on 40 meters. In the world of multi-band vertical antennas, this is a fine performer.
The quality is excellent, although this antenna was made 10 years ago by Hy-Gain.
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| PA0RBA |
Rating: |
2008-02-18 | |
| Great antenna |
Time Owned: 0 to 3 months. |
| My DX-77A is located on top of the house, some 11 meters above ground. It works like a dream especially on 40m, my favourite band. I wanted a large vertical without ground radials and the HyGain does the job. Good quality materials, tuning it is quite a job, but the bandwith is an absolute plus. OF COURSE you need to guy the antenna, HyGain!!. It is a bit strange that I had to make a guying platform on the antenna myself. A plastic kitchen plate does the job together with 3 nylon guying ropes. |
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| WR1H |
Rating: |
2006-06-14 | |
| Can you say "Piece -O- Crap" ? |
Time Owned: 0 to 3 months. |
I heard so many good things about this antenna that I decided to try one. Ordered one from one of the online shops with the "good" return policy.
Well, I was glad I did. Antennas are a hit or miss. It turns out that MFJ destroys anything it touches.
So did the DX-77 go the way of the river ...
The quality was terrible. So bad, that I did not even bother putting it together.
Back it went.
I got a Force 12 Sigma.
Check out the reviews, |
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| HB9DQH |
Rating: |
2005-07-13 | |
| works fine |
Time Owned: 0 to 3 months. |
German
Habe diese Antenne gegen meine 4Bandige von High gain getauscht. Der Aufbau ging relativ leicht, es fehlten aber 2 Schrauben, dafür waren ein paar andere zusätzlich vorhanden. Die Werkseinstellungen mussten leicht verändert werden. Für das tunen haben wir einen swranalyzer von MFJ verwendet, nach 2 Stunden war sie top getunt. Das Teil arbeitet sogar auf dem 80m Band. Sie sollte bis 90km/h Wind ohne Abspannung aushalten, hab sie trotzdem abgespannt. Die Signalreporte sind durchwegs gut auf allen Bändern. Gut ist, dass keine lästigen Radials gespannt werden müssen! So das Beste: Nach ca. 4h sind schon 12 neue Länder im Log! Alles in allem eine gute Antenne fürs Geld. |
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| K5YY |
Rating: |
2004-11-01 | |
| Bad antenna(s) |
Time Owned: 0 to 3 months. |
Have had many old Hy-Gain antennas which worked well, but for whatever reason when MFJ took over a few years ago things went REAL bad. You don't see many good reviews on MFJ products now.
A vertical I bought used a year ago was bought new from MFJ and it looked OK on the ground. Parts fell off during the year. Never again. This is NOT the old Hy-Gain quality at all. Save your money. Gave a "1" because antenna worked fairly well until it fell apart.. Your mileage may vary. |
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| W9NM |
Rating: |
2004-11-01 | |
| Why bother??? |
Time Owned: 0 to 3 months. |
In my opinion, the only excuse for the quality of the construction of the DX77A can be that the original design specifications and drawings were ignored… for ease of procurement, cost, ??? ... and an exceptionally shoddy product is being shipped. I won’t bore you with an enumerated list, if you want one, request via email… they range from misapplication of materials to very obvious damage during manufacturing processes.
If you aren’t able to do some simple strength of materials calculations, and don’t know the proper application criteria of different types of metals, I don’t think that you should consider this product. I spent several evenings making new parts, and the better part of a weekend for assembly and tuning. If you can buy a used one… cheap… then make the new parts that are required… or maybe the older product may be OK as is.
I work about 99% cw, and moving this thing down the bands was not easy. Initially, a couple of bands work great, and the rest are out. Some more new parts and mods and now the tuning is good enough not to require an aux ant tuner at my normal operating frequencies.
I purchased this antenna, at this particular time, because I needed a quick solution… not because I wanted to enter into an R&D project. Had I known that $400 buys so little, I would have postponed the project and scratch built it. I can’t understand a company shipping a product that guarantees that the customer will never purchase from them again.
On air performance is on par for this type of antenna… it is better than using a dummy load. Hi. This design fits a particular criteria… the main considerations being space required, and ability to tune without radials. The four horizontal tubes on the bottom are not radials, but a capacity hat for the bottom side of the vertical dipole. Oh, plan on connecting the outside tips of the tubes together with wire to add capacity.
While I may be getting a little old and irritable, I am a CIO for several companies – including a machine tool manufacturer… and over the years I have been an engineer, project engineer, and engineering manager in the areas of military, consumer, and industrial products. It’s extremely difficult to make a ‘perfect’ product, however, the rhyme or reason behind shipping the current incarnation of the DX77A is inexplicable.
73,
Emil
W9NM
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