Amateur Radio |
Antennas
This is where I will write mini-reviews of the various antennas I have used, and why I prefer specific antennas to others.Diamond SPM-NMO Mag Mount
This is a 4" diameter Magnet Mount for any NMO base antenna. I bought this from Texas Towers for $45 (which I think is overpriced.For some reason, the plastic body is brown instead of black. The magnet seems nice and strong. Included in the package are three soft metal cable clips with sticky back. This is a nice idea as it lets you clip your coax so it doesn't move around.
The other weird thing is the instruction sheet is only in Japanese. This makes me wonder if they figure Americans don't need the instructions or that we won't read them anyway.
Bought Summer of 2009.
Roll-Up J-Pole
I built this antenna from various sites on the net and created my own guide on how to build it.It's a great portable antenna as it rolls up into a very compact space. Since it is a J-Pole it has a nice gain pattern, which makes it very handy for use with a walkie-talkie.
They can be a bit difficult to tune, as normal J-Pole tuning procedures do not work due to it's construction but my guide has instructions on how to tune it.
Built Summer of 2009.
MJF 1724B
This is a 20 Inch Mag-Mount Dual-Band 144/440 antenna. I bought two of these, one for my wife to use with her HT and the other to as a receive antenna for my streaming audio radios.Assembly was easy, though I could tell the antenna was pretty cheap. I don't have an SWR meter handy but I did get a definate increase in signal strength.
I think the coax could be a tad longer, but it reaches in both installations.
Purchased Summer of 2008.
Diamond x200a
This is an 8.2 Foot Fiberglass Dual-Band 144/440 antenna. I have this at my apartment, and it has worked very well for me. I like the 6db gain on 2 Meters, as it comes in very handy for working the local repeaters with minimal power.The SWR has always been acceptable to me, and the construction seems sturdy. Other reviews that I have read have shown some like to seal the mid-point joint with epoxy or sealant to ensure no moisture can get in and corrode the copper internals. I have not done this, but the antenna is either used indoors or under my patio.
This antenna was very easy to assemble, even though I had never had an antenna like this before. When removed from the package, you have three radials, the mounting hardware, base sleeve, bottom element, top element. Attach the internal top element to the internal bottom element with the set-screw included. Then screw on the top fiberglass and radials. Feed your coax through the base sleeve, and attack to the antenna under the radials. There is one set screw. Lastly mount to the mast hardware, and you're set. No tuning is required.
Purchased Summer of 2007. Mfg. Page
Larsen NMO2/70B
This is an all Black Dual-Band 144/440 antenna. It is 36 Inches tall, with a center load coil, and a base load.I bought this to replace a Comet SBB-5NM0 that broke on me. This antenna performs the same if not a little better. The whip is stiffer which helps it maintain it's radiation pattern at 75+MPH. The antenna also feels very sturdy and appears to be well built.
The only assembly with this is to make sure the ship is tight, and screw it onto the NMO mount.
I like this antenna and recommend it for anyone wanting to run NMO on a vehicle. It does not have fold over, so height may be a concern.
Purchased Summer of 2007. Mfg. Page
Comet SBB-5NM0
This is a Black Dual-Band 144/440 antenna with Fold-Over. Antenna is about Three Foot Tall with an NMO mount.I bought this to use with my new Mustang, and I was looking for a mid-price, mid-gain, mid-size dual-band antenna for my car that would outperform a 20 Inch whip. This was what I chose, and it worked well. I never needed the fold over, though it was neat to play with.
I would recommend this antenna, if it wasn't for having to replace it. My car sat through several Ice Storms in 2006-2007, one of which left a sheet of ice on my roof about 1.5 Inches thick. When I went to push this off the side of my car, it instead went off the back and completely snapped this antenna below the fold over. Snapped as in the only thing holding it to the car was the base loading coil I didn't know was there.
After I got my Larsen replacement, I was able to compare the two and see how the slender base of the Comet was more prone to break. I also saw that the ship was a bit thinner, which allowed the antenna to bend over at high way speeds (though not alot).
This is a good antenna, but for the same price I'd recommend a Larsen 2/70.
Purchased Summer of 2004. Mfg. Page
Larsen NMO150B
This is a Black 5/8 Wave Single-Band 144 Antenna. It is over Three Foot long as tuned for Amateur use. The NMO150 is a base-load thin-whip antenna that is tunable from 144-174 MHz.I suppose as 5/8th wave antennas go, this one works just the same. My problem with it is the very thin whip they used. It's fun to see it flop around as you take corners and hit bumps, but I had a hard time making good contacts with this antenna. I had it mounted to a custom NMO Mirror Clamp mount on my semi tractor. The antenna was properly grounded and had good SWR, but it seemed like I couldn't get out. After looking out the window at the antenna while going down the highway, I discovered the problem. The tip of the antenna was nearly 18 Inches behind the base of the antenna. This was changing the radiation pattern of the antenna and making it very in-efficient.
This antenna is good for top of a pickup as it is very flexible, it will give when driving under canopies, but I don't think it performs as well as a stiffer 1/2 wave antenna. As a result, I normally try to steer people toward a dual-band 1/2 wave as they use a stiffer whip to maintain the integrity of the coil in the middle.
Bought Summer of 2003. Mfg. Page
Diamond NR770HNMO
This is a Chrome Dual-Band 144/440 Antenna with Fold-Over. This antenna was bought to use on my old 1972 Dodge Pickup. It seemed to be a very tough antenna, with a very solid steel/aluminum base. It almost seems overly strong as it appears to be milled out of a larger piece of metal.I used this antenna on my Semi to replace the Larsen 5/8 NMO antenna I had, and it worked wonderfully. It took being hit by numerous trees, bugs, ice and the constant wind. I never had a problem with this antenna until I tried to get it off the mount. I had to put it into a vice to get it off, which slightly warped the base.
The fold over worked very well on my pickup, as I parked inside the garage. I ended up leaving this antenna for the trash when I moved due to the bent base. If I need another chrome antenna to take abuse, I'll get another one of these.
Bought Summer of 2003. Mfg. Page
Comet SMA-503
This is a Black Dual-Band HT Antenna with SMA connector. It is about 9 Inches long, very thin and flexible.I bought two of these for our Yaesu FT-60 Walkies, and they have worked very well. This antenna gives over 1 bar of improvement on receive from the stock Yaesu antenna, and is much more flexible. Transmit seems the same if not a little better with this antenna.
The whip tip will come off, so be prepared to superglue it back on. If you loose it, don't worry as it does not affect the performance. I read somewhere that you can tie this antenna in a knot without hurting it. It's true, you can.
Purchased Summer of 2007. Mfg. Page
Comet SMA-24
This is a Black Dual-Band High Performance HT antenna. It is 17" long for better transmit and receive with your Walkie Talkie.I found this antenna was too long, and always kept stabbing me. Yes it is flexible, but that just means it will keep thwapping you on the back as you walk.
If you really need this high of gain with an HT, get a mobile antenna and stick it on the nearest metal surface.
Bought Fall of 2000. Mfg. Page
Copper J-Pole
This is just to pay homage to whoever built my 2 Meter J-Pole. I know the guy lives around Tulsa and is a plumber by trade. He built this antenna using his own set of schematics with an SWR analyser. The antenna uses 3/4 Inch copper pipe, and has both vertical sections caped and sealed (no adjustment screws). The bottom of the J has two and a half feet of extra, so it has plenty of material to mount with.One of the reasons I loved this antenna so much was it's SWR. This antenna would do a 1:1 from 145-148 MHz, and only be a 1.1:1 at 144 MHz. Coupled with a 50 Foot piece of RG-8 and 30' of elevation, I could work any repeater within 50 miles with 10 watts or less and be full quieting.
The recommendation I have from this antenna is use 3/4" copper instead of 1/2" as it is more durable and has a wider bandwidth.
Received around 1998 I think.
SO-239 1/4 Wave
This is a nice beginner antenna as you can see the basic parts of a ground plane antenna without all the fluff. It is hard (in my experience) to get under a 1.4:1 SWR, but is nice practice.I recommend using nut/bolts to attach the radials instead of bending/soldering. It makes a mechanically stronger connection, and makes the antenna stand up to abuse better. Also, try using an aluminum sleeve over the center pin to give your radiator more stability. It also gives you a nice well to fill with solder.
Also, don't try to save a hanger and piece together pieces of scraps to make your radials. Getting the pieces to stay together is more trouble than it's worth.
Made around 1996 I think.
