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Reviews For: Unadilla W2AU/W2VS Multiband Dipole

Category: Antennas: HF: Verticals; Wire; Loop

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Review Summary For : Unadilla W2AU/W2VS Multiband Dipole
Reviews: 17MSRP: 85
Description:
This is a W2AU balun used in conjunction with the Unidilla traps. While the traps are available for all HF bands from 80M through 10M, this antenna is based on the 80/40M trap dipole design found in the ARRL Handbook. The W2AU balun is used with a pair of 40M traps to create a multiband dipole antenna capable of operating on 80, 40, 20, 15 and 10 meters. It is approximately 110 feet in length and provides a relatively low SWR on these bands.
Product is in production
More Info: http://www.unadilla.com
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00174.1
W9DZ Rating: 2014-04-27
Blue core material will crack Time Owned: more than 12 months.
I have a set of the Reyco 40 meter coils that are at least 30 years old and are still in pretty good shape. The coils are wound on a white polystyrene core. I recently acquired a pair of 30M traps. They are wound on some type of blue plastic core. Both have developed longitudinal cracks. When this happens the trap loses much of it's strength and is in danger of pulling apart. I don't believe my problem is unique. The K4LRG website has a repair article written by K4MSG who had the same problem with info on a fix.
K9AUB Rating: 2013-07-26
Junk Time Owned: more than 12 months.
I purchased a set of traps from Unadilla and built my 80-40 meter trap dipole. It performed OK after I got it trimmed up and hoisted into the air about 40 feet up, but after slightly over 1 year in the air, one of the traps physically separated and caused complete failure of the antenna. I sent the broken trap to Unadilla, and got back a haughty response that they had never had one of their traps fail before, and that the trap I had sent them was at least 15 years old. I produced the receipt from AES showing that I had purchased the traps brand new about 1 year earlier, and I returned the other trap for them to inspect. Would you believe, they never acknowledged my letter, never replaced the defective traps, never returned the one good trap, and broke off all communications with me. Seriously, Unadilla??? NO MORE! Fool me once, shame on you. Fool me twice, shame on ME! I would never purchase anything made by Unadilla ever again, nor would I ever recommend any of their products to anyone else. They make flimsy products and do not stand behind any warranty, nor will they treat you with courtesy or respect. Avoid this company!
KE7FPM Rating: 2012-11-14
dont last very long Time Owned: more than 12 months.
I purchased the 5 band kit about 4 years ago, and after 2 years added the 75 meter coils to get on 160 meters. The antenna performed well on 40 75 and 160, for 2 more years, then the 40 meter coils cracked and fell apart.I ran a killowatt into the antenna most nites while it lasted, but I dont think I will keep buying new coils to fix it. I think if I hadnt added the extra weight of the 75 meter coils to get on 160, the original 5 band antenna would have lasted longer. Unadillas customer service is almost nill, so dont bother trying to call ol Ralph on the phone.
KF7OCD Rating: 2011-07-03
Was my back up antenna, it is now my primary... Time Owned: 6 to 12 months.
This was my first antenna. I really liked it however to mount it permanently at the time was not possible. So I did some looking around and bought the 10 - 40 meter ground plane vertical antenna made by Zero Five antennas.

I had the vertical up for about four months and then my antenna mounting situation changed, so I threw up the W2AU and WOW! Since it is not vertically polarized I get WAY less noise and I can do 80 meters no problem.

To be fair to the vertical I am in a VERY high RFI area.

I liked the vertical BUT I LOVE THIS DIPOLE!!!

My dad (AC7X) says: "You may try other antennas however you will always go back to a dipole unless you have a big ass beam and a 60 foot tower like your old man!"

WB2IVU Rating: 2010-04-13
Best trapped dipole ever! Time Owned: more than 12 months.
Living in Rochester NY (original home of RAYCO) I purchased a set of KW-40 traps from Vic at Rochester Radio Supply in 1966. So, after 44 faithful years with never an issue whatsoever, I replaced them yesterday (4/12/10) with a set of new Unidella KW-40 traps. The only reason I replaced the original traps was, I purchased a new SGC power cube and did not want to take any chances with them and the higher power. This antenna has been my only multi band antenna ever.
WD0FIA Rating: 2009-09-20
Nice Multi-Band dipole, reasonably priced. Time Owned: 0 to 3 months.
Well made. I feel it works great and is a good buy. My LDG Z-100's and the Yaesu FT-950 internal tuner have no problems tuning it in the 5 bands. I cannot get them to tune it on MARS frequencies, but I never planned on using it there. Most stations report the signals off of dipole to be 3 to 4 S units higher than my 5BTV verticle.
K4MSG Rating: 2009-05-29
Works FB, still a winner! Time Owned: 0 to 3 months.
Back in the early 1960s I used a trap dipole made with the old Reyco traps – essentially the same as the modern version - and it performed well despite being in a lousy location and not very high (about 15’ at the center) and with part of one leg bent. Also, in those days it was supplied without the W2AU voltage balun which meant that the antenna was unbalanced. I expected the modern version to be at least as functional and I have not been disappointed.

I did modify the design a bit by making the wire elements longer than recommended in the data sheet (32’ inner & 22’ outer). Since I operate 100% CW on HF I made the inner sections 33’ and the outer 24’ and as expected this lowered the resonant frequency on 80 & 40 meters. Overall length of the wire is now 114’ instead of 108’ and the 80 & 40 meter minimum VSWR points are 3560 and 7085 kHz respectively, with 2:1 VSWR bandwidths of approximately 90 and 180 kHz on the two bands. VSWR on 30 meters and above is quite a bit higher but my MFJ-929 IntelliTuner is able to achieve a reasonable (VSWR 1.5 or less) match on the CW portions of all the other bands. I should note that the built-in tuner in my IC-756PRO easily tunes to 1:1 VSWR on the CW portions of 80 & 40 meters.

80 & 40 meters is where this antenna really shines. With the W2AU balun to achieve better (although no doubt not perfect) balance the pick-up of vertically polarized noise by the vertical portions of the coax feed is significantly reduced and the extra wire length definitely improves sensitivity over my 82’ Alpha-Delta DX-DD (which is slated to become my low-mounted 80/40 meter NVIS antenna). The trap dipole is about 28’ high at the center and has yielded very nice signal reports on the two lower bands. Even though it will load on the higher bands I don’t expect superlative performance although sensitivity on 20 meters seems to be quite good and back in the ‘60s I worked a fair amount of DX on 20 with the old trap dipole, a Viking II (120-watt output) transmitter and a surplus BC-348 receiver.

This is a good general-purpose coax-fed wire antenna for multiband use but will require a tuner on the higher bands and on portions of the two lower bands that are outside of the 2:1 VSWR region. Some have reported trap failure problems with high power but I've always been a 100-watt kind of guy and this antenna is definitely a winner under these conditions, and I would expect that 200 watts is likewise not an issue.

W4FCC Rating: 2008-05-01
Great for 75/40 and other bands with tuner Time Owned: more than 12 months.
I've had the Unadilla antenna in service for 2 1/2 years- W2AU balun, 40 meter traps- just over 50 feet on one end sloping down to 22 feet. The instructions give suggestions for wire lengths for general coverage on most of the HF bands, but I optimized mine for 75/40 phone. As it is now, I have VSWR below 2:1 from 3875-4020, and 7080-7300.

I also broke out some 1/2" PVC and made some spreaders and added a 20 meter dipole in parallel. Without an analyzer it took quite a bit of hauling the antenna up and down to resonate the 20 dipole, and it ended up being about 4" short per leg compared to the 486/f formula, but it did not affect tuning on 75 or 40 at all. The antenna with the trap tunes just fine on 30,20, 15, and 10 with an MFJ 941, but I wanted to be able to use my Heath SB-200 on 20 and wanted a low VSWR.

My TS-520SE tuned 20, 15, and 10 without the tuner, but I thought I'd spare the finals of my IC-718 the stress and bought the tuner. This antenna is used fairly often on the 3905 CC 75 and 40 meter nets, usually with 1200W PEP and it's done great.

I recommend this antenna, and would suggest weatherproofing the coax-to-balun connection. This antenna is spring-loaded on one end, and has survived some vicious winds with no change in VSWR.
W2PL Rating: 2007-11-28
Good Product - BAD customer service! Time Owned: more than 12 months.
I have used several of these over the years. Can't say anything bad about the product. The balun & traps work great. The one time I had a simple question after being a repeat, long-time customer I got zip for a response. That gets you a 3 in my book. NON-EXISTENT customer service -- a pity.
K3ICH Rating: 2007-07-07
160/75/60/40 meters, 2 sets of wires Time Owned: more than 12 months.
I have a dipole arrangement using two sets of wires and two sets of Unadilla traps that has been a very good performer. Except for the slight loading (shortening) effect of the traps, it is almost a full half wave on 160. One leg has 75 meter traps for 160/75 coverage and the other leg has 40 meter traps for 60/40. The shorter leg droops about three feet below the longer top leg and is tied off to it with nylon rope. It is between two supports that are 110 feet apart, so the extra length comes away in a downward sloping, "lazy" Z pattern. The 75 meter traps are about 12 feet out on the legs of the Z, but it doesn't seem to have any bad effects on operation. The center is about 45 feet up and the ends of the "Z" are about 25 feet up.

I usually run 350 watts of AM where it's allowed and have not ever had a trap failure. I would add the caution to make sure the traps are tuned for the segment of the band you need. Don't expect 80 meter (CW/low end tuned) traps to work properly if you're running any power on 3900 kHz. I think the problem may be worse, as far as power dissapation in the traps, if the situation is reversed. That is, using 75 meter SSB/hi end tuned) traps on 80 (CW)

Over the years I have had various dipole antennas up using different Unadilla traps. All have worked to expectations.