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Reviews For: Nelson Antennas 9:1 balun

Category: Antenna parts, accessories, incl. baluns, hardware, etc.

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Review Summary For : Nelson Antennas 9:1 balun
Reviews: 10MSRP: 37.99
Description:

An accessory that enables the use of a single wire to
operate as an effective multi-band antenna.
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00105
K8RDG Rating: 2022-07-20
Un-Un Works as Advertised Time Owned: more than 12 months.
I've experimented with several portable antennas. The Nelson UJM-150 works as advertised and outperforms the others. When operating portable, I use it with 75 ft. of wire configured as an inverted L ~16 feet above ground between two trees. 60 feet of it is horizontal and 15 feet of it is vertical with the transformer at the low vertical end. No counterpoise needed. With 100 ft. of RG8X coax and an air-wound, open core coax choke at the transceiver, the SWR is the following:
80M = 2.0
75M = 1.5
60M = 3.3
40M = 2.1
30M = 1.5
20M = 2.0
17M = 1.7
15M = 1.8
12M = 1.8
10M = 1.6
6M = 2.0
Unlike other antennas and transformers I've tried, the Nelson UJM-150 un-un transformer works as advertised. It's well-built, light weight, and easy to deploy. The only limiting factors appear to be propagation and physical location which are dynamic to any deployment. The UJM-150 comes with instructions and describes other recommended lengths of wire and configurations as may be necessary. I recommend this un-un transformer as an inexpensive (by comparison) solution to anyone with challenging conditions or desiring to operate portable. It can also be a permanent installation if desired.
VK3PDG Rating: 2022-03-06
Excellent balun/wire assembly. Works really, really well. Time Owned: 6 to 12 months.
I'm using a Nelson Antennas 9:1 balun end-fed 71 foot wire, about 4 metres above ground from a difficult urban back yard. It consistently out-performs my multi-band dipole and is now my main antenna for all bands from 10 to 40 metres. I am very pleased with the antenna, as it was simple to install, even coming with a list of recommended wire lengths to suit different size yard allotments. Money well-spent. VK3PDG Mark.
NE5B Rating: 2021-11-01
Great unun 7 BAND WAS confirmed in less than a year! Time Owned: more than 12 months.
I have used this 9:1 unun for nearly 2 years now.

I went with the stainless model and it shows no signs of oxidation or rust. The black plastic has faded just a tad, but it does the job no mater how it may look.

In the first year using this unun with a random length endfed wire (Aluminum Elec fence wire at that) I managed to confirm WAS via LoTW on 10m, 15, 17, 20, 30, 40, 80.
A few months later I wrapped up WAS on 12 and 160.
I admit this was using FT8, but the point is I did it all with basically a single antenna. I have 42 states on 6m the remaining are probably going to require a beam or a bit more time.

I need 3 more countries to have DXCC using this unun.

All with 100watts or less.

In 27 years of hamming, I've never had an antenna that would work on all bands with or without a tuner.
I only need a tuner on a couple of bands.


In all fairness I have to admit 2 things:
1) I did have to play around with various lengths of wire and added a short counterpoise to get the SWRs as low as I did.

2) I had to add about 20' to the wire to get SWR on 160 under 3:1 which upped the SWR on 20 and 80. But hey I already had WAS on those bands.

I cannot say enough good things about this unun.

73 Ben - ne5B
KB6HRT Rating: 2021-04-28
Works GREAT! Time Owned: 0 to 3 months.
Had to go to a wire antenna for 160m in my small back yard! The Nelson antenna 9 to 1 unun did the trick.
1863 1.49 swr
3915 2.50
7200 1.80
14.332 1.29
18.130 1.07
21.300 1.40
24.950 1.30
28.400 1.37 This is a great antenna that is 125' long.
KB6HRT
KD2HPQ Rating: 2020-06-09
Very good value Time Owned: more than 12 months.
Every ham should own at least one of these devices. I own 2. With this 38 dollar device and some spare wire anyone can be on HF. I've spent 5x as much on antennas that don't work half as well.
K6GBW Rating: 2020-05-15
Excellent UnUn! Time Owned: 3 to 6 months.
I bought one of these to make a small portable antenna. I put a 36' long piece of 18AWG wire on it. I hung it up rather low for testing at only about 12-15 feet and with 20 watts I was able to just make contact with a station in Indonesia on 20 meters from Los Angeles. That's great on a good day, let alone with a small compromised antenna. I found this antenna tuned up very easily on 40 meters and up using an external tuner. Over all I'm very impressed with these little UnUn transformers. The only real improvement I would make is adding a strain relief for the antenna wire. But you can easily add that to the support cord using a dog bone insulator.
W5ODP Rating: 2019-12-02
Good stuff! Time Owned: 0 to 3 months.
Bought three to get the discount. I wasn't expecting much as I live on a small lot and can't put up a very long wire. Was able to put two 60ish foot wires up fed at about 25 feet: One for East/West coverage and one for North/South. They work GREAT!! I highly recommend these if you're limited by space restrictions!!
KK6NLZ Rating: 2019-08-23
Perfect SOTA Time Owned: 3 to 6 months.
Love mine...

Watch HIS video!!

https://www.youtube.com/watch?v=lQVTnKQuKaM
KC8PX Rating: 2017-11-04
I recently purchased the Nelson 9:1 unun and am VERY SATISFIED! Time Owned: 0 to 3 months.
My new antenna consists of the Nelson 9:1, MFJ, RF choke, telescopic HD mast and their lightning surge protector. The wire is 84.5 foot long, in an inverted L configuration. I put it up 8 days ago, and have worked 38 countries on 5 of 6 continents. Still lacking oceania, but not bad for a week! Best DX being Mongolia to the East, and Argentina to the South. My SWR is 160=1.7, 80/75=2.4, 40=2.4,30=1.5, 20=1.6, 17=2.1,15=1.16, 12=1.9, 10=1.7. All bands are very broad. I reside in a restricted neighborhood, and with the tall for trees right next to the "green" mast, no one can see it! So, yes, I am VERY SATISFIED.
NZ5L Rating: 2017-06-04
light, compact, and versatile Time Owned: 0 to 3 months.
This device is actually an "Un-un", as it has terminals for a wire, counterpoise, and co-ax.
By careful choice of core and windings, a 9:1 impedance transformation is achieved, enabling a single wire of appropriate length to act as an end-fed antenna. In my installation, a 44' piece of wire is usable on 40 and 17 Meters with no tuner at all. Most of the other HF bands are within range of a typical built-in tuner, including 80 meters. For a counterpoise, I used one 30' length of wire on the ground.
The results have been surprising. The performance is comparable to an endfed half-wave type of double the length. In field use, I have been able to make many qsos using a QRP rig of only 4W output. Signal levels are surprising.
This small, lightweight device is ideal for traveling, and also durable and weather sealed. Power rating is 150W, and I have used it with my FT-950 with no problem.
I rate this as an excellent value, and a very useful and clever device, particularly for portable operations.