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Reviews Categories | Antennas: HF Portable (not mobile) | MFJ-1661 Help


Reviews Summary for MFJ-1661
Reviews: 4 Average rating: 4.3/5 MSRP: $$129.95
Description: Portable antenna of the Manual Screwdriver type, for 40-6M.
Product is in production.
More info: http://
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N4NUI Rating: 3/5 Apr 24, 2013 17:57 Send this review to a friend
Good Performance - Typ MFJ Poor Assy  Time owned: 0 to 3 months
Okay, I have had the antenna on the car for three weeks. I am surprised how well it works. BUT, it has the typical MFJ manufacturing quality problems.

First, I suddenly noticed a scraping noise when I moved the coil sleeve to change bands. Secondly, they used SS for the 3/8" bolt and nut that connects to the whip base but they scrimped and used a cheap steel lockwasher and that has already rusted badly becuase the rain. There is no lockwasher under the head of the bolt inside the end cap and the first time I changed whips it spun loose. The third issue is that rain water gets trapped in the cylindrical base of the coil assembly. The next issue is that the crimp connector on the lead from the end of the upper winding of the coil that connects to the short wire that has the ring connetor connected to the 3/8" whip mount bolt is made from aluminum and I am already seeing some white corrosion.

I had to take the darn thing apart to tighten the whip mount bolt and when I did, four large aluminum maching chips fell out and a fifth one was entangled in the lower bronze wipers - thus the scraping noise. That was when I also discovered the trapped water and the corrosion.

I would still reccommend the antenna because of the performance versus the price. But, I would suggest you take it apart and put some red thread locker on the whip mounting bolt threads where the main nut rests (avoid getting it on the PVC cap, change the steel star lockwasher to SS, dump out the maching chips, drill a fine hole next to the bolt head in the bottom of the lower end plug to drain water, and spray some dry Teflon lubricant on the sections of the two whips.

I also clipped off the aluminum crip connector and replaced the lead from the upper end of the coil wire to the whip bolt with a insulated stranded wire and soldered it to the coil wire and put on a gold plated eye connector (AutoZone)for the whip bolt connection.

The instructions state that one must use the supplied matching coil for the lower frequencies to get a good match. It may be my specific installation using the Gorrilla magnetic mount and two 10 gauge leads from one of the magnetic pad polts to the door latch frame bolts on either side the car, but my installation ends up with a 40-meter swr of 1.2 at the 52 ohm point with the long whip fully extended (car parked). I tune the antenna using the FG01 antenna analyzer from Ten-Tec and with the low SWR when I push the ATT button on the TS-480 - the tuner just clicks and says "Why are you bothering me with this?" (:-)

I just received an aluminum spearker tripod and when the weather cooperates I'll see how the antenna works "portable" mounted on the tripod mast with twelve 10-foot radials made ftom 300 ohm TV twin lead.

 
N4NUI Rating: 4/5 Apr 20, 2013 11:21 Send this review to a friend
Works with a Gorilla Mag Mount  Time owned: 0 to 3 months
I travel on-the-job and recently have had to use rental cars. The rental companies don't like you to drill holes in their cars or chip the paint with "lip" mounts. I have tried many different mobile HF antennas with magnetic mounts. The MFJ-1661 works very well with the 4.5 foot whip while moving and the long whip when parked or on a tripod with twelve #10 12' long radials. The ground to the auto frame is a #10 insulated wire from one of the machine bolts on the mag mount to a door latch star bolt on the door frame. I wrap the ground wire and the antenna line with foam tape to keep from scuffing the car paint when moving.

The tuning is very sensitive to the coil adjustment and using a good antenna analyzer saves a ton of fiddling to get a good match. I use the great FG-01 purchased through Ten-Tec because it has a nice graphical display and the tuning is much more stable than my big MFJ analyzer. Resonance on 30 and 40 meters does require the supplied matching inductor between the thumb screw on the fixed part of the coil and the ground point on the mount. The wing screw on the antenna is NOT for a ground or radials. The 40meter operation works "Okay" with the short whip but much better "portable" with the long whip and the antenna mounted on the tripod with the radials. I routinely can get the match down to 1.2 from 40-m up to 6-m with careful tweeking of the coil slider position. For the price and the suitcase size when disassembled, it is a great value. I suspect that the little TarHeel motor tuned screwdriver would work as well with the Gorilla mount, but at 3X the price.
 
KG7RS Rating: 5/5 Aug 16, 2011 19:27 Send this review to a friend
Excellent Portable Antenna  Time owned: 6 to 12 months
NZ5L said it well. I also have the MFJ-1661 and its a great all-around portable antenna for both QRP and 100 watt use. My experience with MFJ products has been mixed, but this product is reasonably well made and is the best design I've found among short loaded verticals. This is one MFJ product (there are several others) which I'm proud to own.
The collar slides easily and accurately resulting in tuning that is very repeatable. Due to the collar design it's easy to mark the coil settings for each band with a sharpie marker, then overlay the markings with clear tape to keep them from rubbing off. The 10' telescopic whip is indeed somewhat delicate but I don't know how it could be made more robust without substantially increasing its collapsed size and weight. I've found it can withstand reasonably stout winds but I wouldn't allow it to fall over - damage would likely occur. The shorter whip supplied will not collapse to a length as short as the 10' supplied whip but is of a far more robust design which reminds me of a 1960's auto radio antenna! It should certainly be rugged enough for mobile use.

I use my 1661 mounted to one of the excellent Super Antennas MP-1 tripods, which appear to now be out of production. Any low tripod can be used successfully. As NZ5L said, use 8-12 untuned radial wires just laying on the ground. Mine are made of 22AWG stranded hookup wire available from Radio Shack. I use 8 of them, each 10' in length, but the length is not critical. The more radials deployed, the better the efficiency. 8 seems to be a good balance between fast easy deployment and reasonable efficiency. Bear in mind that this recommendation is based on a ground-mounted antenna on which the feedpoint is no more than a foot or two above ground. If the feedpoint is raised such as on a mast, at least 1 radial per band, cut roughly 1/4-wavelength must be used. I've found little advantage of deploying field portable vertical antennas with an elevated feedpoint. The benefit of ground mounting and untuned ground radials is far easier deployment. As always, "your mileage may vary" and experimentation is part of the fun.

I decided not to use the supplied base matching coil in favor of a 500v silver-mica capacitor which is connected in parallel with the feed point (same as the supplied base matching coil). to provide base matching to 50-ohms and consequently lowest SWR. Some pre-field work with an antenna analyzer is helpful both in pre-marking the band settings on the coil but also in determining the effect of fixed capacitors on base impedance. I found I needed to carry only two fixed capacitors in my portable antenna kit - a 150pF for the 20, 30 & 40 meter bands and an 82pF for 17 & 15 meters. 10 & 6 required no matching capacitance at all. The values are based on the 10' whip fully extended and eight 10' ground radials deployed. The result is a nearly perfect match on each band - quickly and easily repeatable. Higher value capacitors are required for lower frequencies of operation and vice versa. MFJ also makes a nifty capacitive mobile matcher which connects inline between antenna and feedline to make matching even simpler than using discrete caps. Take some time in presetting and marking and leave the antenna analyzer at home.

As a long time & very avid portable op I've heard all the comments - "why not save your money and just throw a wire into a tree". In some cases such a comment represents wisdom. When operating where there are few or no natural supports however, the 1661 is perfect. A short ground-mounted loaded vertical exhibits a low radiation angle - a substantial advantage over end-fed horizontal wires and low dipoles typically deployed in a portable environment. My typical field contacts on 20 & 30 meter CW are usually to the east coast and SE from AZ using the 1661 vs much closer using NVIS low dipoles. No magic here - I find the 1661 performance very similar to other small loaded verticals commonly used for field deployment. I have found the 1661 (and presumably similar MFJ versions such as the 1662, etc) among the easiest to use. Although I haven't tried, I suspect the 1661 would make a great mobile HF antenna as well.

73, John, KG7RS
 
NZ5L Rating: 5/5 Jul 27, 2011 07:40 Send this review to a friend
Works well, convenient.  Time owned: 0 to 3 months
This antenna is reviewed in the Mobile antenna section, but a number of reviewers gave it a low mark because the whip part did not stand up under mobile use. MFJ states emphatically that the long whip is not to be used while mobile. I have had good results using this system as a portable, with 8-12 ground radials (they do not have to be perfectly resonant for each band). A small base matching coil was included by MFJ, and its use is necessary on 40 and 20. Use of an antenna analyzer is recommended, as moving the collar only slightly changes the SWR a great deal.
When properly tuned and deployed, results were very satisfactory. I recommend it to potential portable ops - especially near the ocean.
 


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