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Reviews For: MFJ-1785, 3 HF Low Band 80,40,20 M Rotatable Dipole.

Category: Antennas: HF: Yagi, Quad, Rotary dipole, LPDA

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Review Summary For : MFJ-1785, 3 HF Low Band 80,40,20 M Rotatable Dipole.
Reviews: 6MSRP: $359.95
Description:
MFJ-1785 Low Bands on 80,40,20M. With Efficient full 33 foot Rotatable Dipole.Handles 1500 Watts PEP. 6063 T-6 Aircraft strength Aluminum tubing with solid fiberglass Insulator.

"NEW DX LOW BAND ROTATABLE DIPOLE"
Product is in production
More Info: http://www.mfjenterprises.com
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0063.7
KD8NCP Rating: 2013-08-22
KD8NCP Time Owned: 3 to 6 months.
First of all, this is a pretty big antenna (10.5m) and I HIGHLY recommend that you construct the temporary stand that MFJ mentions in the instructions. My temporary stand was a 10m high telescoping mast that I continue to use because I can collapse the mast to add/remove tuning spokes to fine tune resonance on the three bands, and then raise the mast to the final height of 10m. The resonant frequency on each band increases as the antenna height increases, so there was a lot of raising and lowering the antenna to tune the antenna before I was 100% happy with the tuning results. The balun is in a PVC rectangular case and is a pretty simple 1:1 ferrite bead balun, it developed a short in the first month of operation, so I removed the case and made some improvements that solved the problem. The biggest lesson learned with this antenna is the need to thoroughly tighten all nuts and bolts before you put this antenna up in the air. For the price, I'm happy with this product and learned a lot about tuning spokes in the process.
KC6ZWH Rating: 2011-03-13
GOOD Time Owned: 6 to 12 months.
To my surprise MFJ sent me a different mounting bracket after i complained that the original bracket was very inadequit. No teeth on the v bracket. This allowed the antenna to spin around the mast. I now have a beefy bracket for this. What they sent me is the mounting hardware for the A3S for my MFJ-1785.So my congrats to MFJ for doing this. The antenna works as advertised.It is just a dipole that rotates
W3MIL Rating: 2009-05-04
DARN GOOD DIPOLE Time Owned: 0 to 3 months.
MY EXPIRIENCE WITH THE MFJ 1785
PRO-S
A GREAT DIPOLE EASY TO PUT TOGETHER AND TUNE VERY DISCRETE BLENDS RIGHT INTO THE SKY, WORKS ALL THREE BANDS LIKE YOU WONT BELIVE 80/40/20/
YOU COULD STEER OUT UNWANTED NOIS I HAVE WORKED THE DIPOLE ON ALL THREE BANDS AND IT JUST PROFORMES GREAT AND FOR ME THE SAME ON ALL THREE BANDS I GET NOTHING BUT GREAT REPORTS ALL AROUND. AWSOME PRODUCT .
CON-S
COULD USE A HIGHER QUALITY BALUN FOR THE PRICE OF THE DIPOLE. THE ONLY REASON IT GETS A 4/5 IS BECOUSE OF THE BALUN OTHERWISE WOULD SAY 5/5
WB6YZZ Rating: 2008-11-08
Pretty good compromise Time Owned: 0 to 3 months.
I had a vertical tuned with an SG-230 in the corner of the yard. I wanted an NVIS antenna for the lower frequencies and something that would allow me to steer out of noise sources with a little directionality. I saw this antenna and thought it was the perfect fit. NVIS on 80 and 40, starting to have some directionality on 20. I planned from the beginning to remove the balun and feed it with ladder line from a tuner, so I could get wider bandwidth on the lower bands. So far, so good. It is only about 16 feet high on my single story roof. It works as expected.

The only problem with it is that the instructions were a little unclear about how to build the support steel cable. MFJ only provided 30 feet, and after connecting one side, the cable left for the other side was too short. I rebuilt the support cable with steel "rope".
WA5CMI Rating: 2008-07-25
Great 75-meter dipole Time Owned: 0 to 3 months.
Have had the 1785 up for a couple of weeks now, and I am very impressed with how well it works on 75 meters. I bought it for that band only as I have other antennas for 20 and 40. I tuned it for 75 AM and left it at that. I have gotten very good signal reports, very good. On the negative side, the overall quality of the 1785 is lacking. One thing in particular is the mast clamp if flimsy. It tends to spread out as it's tightened. The spoke mounts at the ends are loose and can not be securely fastened. End loading is by far the way to go with shortened dipoles. This antenna gets out, at least on 75.
W5LE Rating: 2008-05-25
My experience with the MFJ-1785 Time Owned: 6 to 12 months.
I put up the MFJ-1785 in July 2007 at my QTH in Oklahoma.
I found that even with 500-1000 watts it felt like a dummy load 60 feet in the air on 80. I had what I would categorize as respectable performance on 40.
I modified mine to cover 30 meters instead of 20, since I had a 5-element monobander on 20. I had reasonable performance on that band.
In December 2007, an ice storm hit Oklahoma and the MFJ-1785 rotary dipole wasn't equal to the elements.
It is now hanging down on both ends and looks like an upside down U. The support cable nor the boom strength were equal to severe weather.
I had high hopes with this antenna, hoping to be able to cover 80 and 40 with other than dipoles or slopers, giving the added benefit of being able to rotate. I was disappointed.
In a nutshell, I would say it needs a much stronger boom and better support cabling. Until that happens, I consider the MFJ-1785 a "fair weather" antenna.