Mobile Antennas / Good Places to Purchase

[Colin9690]

Hello all,

As the title implies, I'm looking to buy a good mobile mag-mount antenna for my newly-purchased Uniden 980SSB. I was big into CB radio about 15-20 years ago, and have decided to re-enter the game with a basic mobile setup.

I drive a 2-door Honda Civic, so if possible, I'm looking for a magnet mount antenna that is of the "low-profile" design. However, I'm also open to the idea of a larger magnet-mount model if the performance gains from one of these is considerable.

My question is, what websites out there are good places to start looking for an antenna? I've done some Googling, but I'm trying to gather an understanding of which sites are trustworthy / worthwhile to purchase from. Thank you in advance!

 

[mmckenna]

A long time ago I learned that spending the money and getting a good antenna made a huge difference. Skip the Chinese brands, Browning, Tram, etc.
Also, learned that antennas are governed by the laws of physics. No manufacturer has a way around that. No manufacturer can cheat science and sprinkle magic pixy dust into their antennas and make them work better. Getting quality hardware is the way to go.

Best CB antenna I've ever owned is the Larsen NMO-27. I've had mine for nearly 30 years. After I bought it, I never needed another. Might cost a bit more, but it's worth it in the long run.
The other big benefit is that it uses the industry standard NMO mount. That means that at any point down the road if you decide to do a permanent mount, you can unscrew it off the magnetic mount and screw it down onto an NMO mount. Also, if your interest change, you have a standard antenna mount that can be used for other radios/frequencies.

I had the Larsen NMO-27 mounted on a permanent NMO mount on my truck. Using an antenna analyzer, I had it tuned down to 1.3:1 SWR on channels 1 and 40 and a nice 1.07:1 on channel 19. Worked great on a 4000 mile plus road trip from California to Texas and back.
I've also beat the crap out of this antenna on tree branches, low parking garages etc. No issues, even with nearly 30 years on it.

https://www.theantennafarm.com/catalog/larsen-nmommrpl-1097

https://www.theantennafarm.com/catalog/larsen-nmo27c-699

Here's the SWR plot from the antenna analyzer:

For small quantity antenna orders, The Antenna Farm is hard to beat. Good prices and they tend to have everything in stock.

 

[BloodandRoses]

Bobs CB

 

[n1nte]

+1 on the Larsen - you won't regret it, works very well
+1 on The Antenna Farm - been happy with prices and service from there

 

[alcahuete]

Larsen makes good commercial products, but is not the best CB antenna by any stretch of the imagination. My Wilson 5000 routinely out-performs my NMO-27 by 3 S units on both receive and transmit.

 

[Colin9690]

Thank you everyone for the pointers, I’ll check out Larsen / Wilson. Should be a good place to start, if nothing else. Thanks again!

 

[Ensnared]

Hello all,

As the title implies, I'm looking to buy a good mobile mag-mount antenna for my newly-purchased Uniden 980SSB. I was big into CB radio about 15-20 years ago, and have decided to re-enter the game with a basic mobile setup.

I drive a 2-door Honda Civic, so if possible, I'm looking for a magnet mount antenna that is of the "low-profile" design. However, I'm also open to the idea of a larger magnet-mount model if the performance gains from one of these is considerable.

My question is, what websites out there are good places to start looking for an antenna? I've done some Googling, but I'm trying to gather an understanding of which sites are trustworthy / worthwhile to purchase from. Thank you in advance!

The Tram 3500 model is a great antenna. According to a radio technician in the area, you can buy this antenna or one like it, including the rubber boot on the bottom, in pieces like you could with K40. However, I don't know where to order the one with individual parts of the antenna assembly.

https://www.amazon.com/TRAM-3500-Heavy-duty-Magnet-Mount-Antenna/dp/B008S5N09M

 

[JayMojave]

Hello All: Wow just a few postings and its a great thread. The VSWR Plot from MMmckenna is very impressive that ones opinion is backed up by a network Analyzer Measurement. But as he says there is NO Magic Pixy Dust to make antennas work. Dats right!

That being said and few local stations and I did a mobile antenna field strength test of many different. Living out here in the wilds of the Mojave Desert a natural outdoor antenna range, we tested the different antennas while the few base stations gave S-Meter readings from a mobile out in the wilds of the desert. The point of this thread is that the longer antennas ( 102 inches ) had the strongest S-Meter reading as compared to the shorter antennas. These comparison antenna measurements were repeated several times to insure they were all repeatable and operators telling the truth. Even a 6dB attenuator was put in line to show a should be full S-Unit decrease in field strength. Which showed more that a single S-Unit due to the fact the CB Radios did not have a 6dB per S-Unit, more truth telling.

VSWR and Bandwidth measurements do not tell the hole story only that a store bought antenna should be working out of the box. But very close again for a purchased antenna. So smaller antennas do work but be advised they ain't the best antennas out there. They are a convenience of operation, a trade off from a longer antenna, that hits all kinds of low lying signs, wires, and such.

I use a magnet mount Wilson 5000 on my mini truck that allows me to hear the local ho raw stations bad mouthing me, and carrying on. My larger 4x4 truck I use a custom made 96 inch fiber glass antenna mounted on top of the cab that works quit well.

Jay in the Great Mojave Desert

 

[mmckenna]

Yes, 1/4 wave whips are awesome antennas. Absolutely use one of those if you can.

However, on the OP's Honda Civic, it might be problematic.

 

[FiveFilter]

I would shop the Internet a bit to see who offers what at good prices. I can't testify for any particular vendor at this point since it's been years since purchasing an antenna.

For my Mazda3 sedan, I use a sleek Wilson 500 mag-mount on the roof, which has a stinger about 56 inches long as trimmed for resonance. I see an SWR of about 1.2 on Channel 19, which is where I use it. Even when I fire up my small RM Italy 203P amplifier producing about 70 watts, the SWR is about 1.3. I get really good results from the 500.

On my big ole F250 diesel, I can stand a little taller stinger, so I use a Wilson 1000 mag mount at about 62 inches long. I didn't even have to trim it for resonance. Works really good too!

 

[JayMojave]

Yeah that could be problematic but still doable. I have seen a lot of small cars with a 96 or 102 inch whip antenna on them mounted in the middle of the car. A local with a VW bug has a 102 inch whip mounted and gets out like gang busters, and I don't think he running a linear, could be wrong there.

Jay in the Great Mojave Desert...…. Just down the road ah ways from Miss Dinahs fillin station.

 

[AB4BF]

Last week, I installed a new antenna for a friend of mine who is a member of a deer hunting club in the lower part of SC. A year ago, I had installed a magnet mounted Laird for him and tuned it to his specified frequency of channel 10, 27.075 MHz AM. Absolutely no standing wave. As i said, last week, he came over stating he needed another antenna, one that wouldn't be knocked off in the woods. From Amazon, he had ordered a ProComm whip, one that looked like it was right off a '60's highway patrol vehicle.
I suggested that he mount it on the middle of his aluminum toolbox but he showed me that the aluminum was too thin there and said that all of his hunting buddies place theirs on the side corner of the toolbox where the aluminum was more stable. He's the customer and thats where I placed it thinking "I'll never get the SWR down low enough for his Galaxy CB to work properly".
I prepared the cable, an Astatic 17 foot cable, (those are well made cables) doused it with hot melt glue after soldering T&B thick copper lugs on the center conductor and shield and heat shrank waterproof shrink tubing over it all.
Inside, I hooked my Comet 500 analyzer to it and centered the SWR screen to channel 19, 27.185 MHz. The trace started at about 25.9 MHz and just after 26 MHz the trace took a dive to the bottom, looking like a square wave and stayed there until the trace got to about 28 MHz and went straight up like an F-15 on afterburners. I have never seen a trace like that or as good as that. My eyes must have been wide open, cause my friend asked "Whats wrong?"
Not a thing, I said, You'll have no problem with this antenna. I did not touch the antenna in any way to affect that good of a trace or SWR. I verified with my inline SWR cross needle meter. The SWR side never moved, from channel 1 to channel 40.
Sometimes, I think, you just get lucky...

 

[prcguy]

So let's see here, "S units" are 6dB between the numbers 1 and 9, then its supposed to be in dB above S9. That means if your Wilson 5000 outperforms an NMO-27 by 3 "S units" then it has 18dB more gain than the NMO-27. That would be the same as going from 4 watts to 252 watts just by swapping antennas. Or on a base station that would be like going from a 1/4 wave ground plane to a 20 element Yagi.

Personally I think that's highly unlikely and I would be surprised if there is more than 1dB difference between the two antennas. Have you considered your NMO-27 might be broken?

Larsen makes good commercial products, but is not the best CB antenna by any stretch of the imagination. My Wilson 5000 routinely out-performs my NMO-27 by 3 S units on both receive and transmit.

 

[n1nte]

In mobile installations a number of things can go wrong to make a good antenna perform poorly - poor placement, lack of a good ground plane, pinched/damaged coax (very common), etc. A dummy load can have a 1:1 SWR but that doesn't make a good radiating antenna. Longer antennas tend to perform better than shorter ones as base, center, or top loading coils are a compromise. In order to fairly compare antennas they need to share the same mount, coax, and placement. A lot of other variables get added to the equation when they aren't.

My preference toward Larsen antennas comes from the fact that they are often installed in public safety and commercial vehicles. They tend to perform very well and are usually pretty rugged. That doesn't preclude that a Wilson 500 won't work well at all, in fact I've seen them work well myself. I used to be a fan of the K40 antennas in 80s which was before I got involved in commercial land mobile radio.

Whatever you decide to do, remember that the antenna is a critical part of the radio system as a whole and will make a big difference in how well your radio works.

 

[alcahuete]

So let's see here, "S units" are 6dB between the numbers 1 and 9, then its supposed to be in dB above S9. That means if your Wilson 5000 outperforms an NMO-27 by 3 "S units" then it has 18dB more gain than the NMO-27. That would be the same as going from 4 watts to 252 watts just by swapping antennas. Or on a base station that would be like going from a 1/4 wave ground plane to a 20 element Yagi.

Personally I think that's highly unlikely and I would be surprised if there is more than 1dB difference between the two antennas. Have you considered your NMO-27 might be broken?

Yep, I understand the numbers. I can't use the same mount, since the Wilson is not NMO, so there will be a difference there, but those are the numbers I get. It is the absolute best performing CB antenna I have ever used, outside of a 102" whip. The NMO-27 does not come anywhere close.

 

[cmdrwill]

The NMO-27 does not come anywhere close.

Must be the weird sand in your part of the desert......

 

[prcguy]

The Larsen NMO-27 is a very good antenna but my personal preference in an NMO mount is the Antenex/Laird CW27. Its 15 inches longer than the Larsen and works better plus and is wide band, no tuning needed for 26.8 to 29.7MHz.

 

[petnrdx]

As others have said here, you can't cheat laws of physics.
Anecdotal tests trying to compare different antennas using a S meter really are not accurate enough.
I have done EXTENSIVE testing with equipment costing tens of thousands of dollars, and even that won't get precise results.
Our testing showed such a variation of gain, undesired "directivity" and radiation angle, that at VHF and below every antenna is a compromise. At 28 mhz, you would need a 20 ft diameter counterpoise (ground plane) to fairly compare antennas.
Not too useful since we can't replicate that with a vehicle.
Yeah, in GENERAL a longer, not loaded antenna is better, but PLACEMENT on the vehicle is of much more importance.
More important by up to 20 dB. Measured at far field, 360 degrees, and vertically from -5 degrees to +10.
So my suggestion, based on a LOT of fairly scientific measurement is to get the antenna that is DURABLE, suits your clearance needs, and mount it as high and centered as you can.
Much of the "difference" people find in anecdotal testing is a variation in "directivity" caused by placement of the antenna on the vehicle or radiation angle. (up tilt).
Most of the antennas we have tested that are "colinear" show uptilt. OK if working repeaters on distant mountains, or skip.
Useless to have uptilt on simplex.
Our testing used very high quality test equipment and drones.

 

[petnrdx]

Further, return loss (or VSWR if you prefer) only tells part of the story. Again, placement of the antenna will affect the RL pretty significantly. Opening a door on the veh will affect RL. Other traffic next to your vehicle. Etc.
Yes, get the best match you can. BUT remember that inserting or removing a wattmeter may affect your readings more than you might expect.
And "low loss" feedline is really not a concern at that low of frequency (it isn't much of an issue even at 800).
With say a poor 2:1 SWR and 10 ft of cheap RG58 vs. something "low loss" you are probably talking a couple tenths of a dB of loss difference.
Get quality stuff, use good technique and get on with your life.
I tend to like Larsen (knew him) but also like the Antennex as they didn't break as easy.
Any CB antenna longer than about 5 ft should work pretty well.

 

[prcguy]

Are you using something like a raspberry pi with spectrum analyzer dongle on the drone for measurements?

As others have said here, you can't cheat laws of physics.
Anecdotal tests trying to compare different antennas using a S meter really are not accurate enough.
I have done EXTENSIVE testing with equipment costing tens of thousands of dollars, and even that won't get precise results.
Our testing showed such a variation of gain, undesired "directivity" and radiation angle, that at VHF and below every antenna is a compromise. At 28 mhz, you would need a 20 ft diameter counterpoise (ground plane) to fairly compare antennas.
Not too useful since we can't replicate that with a vehicle.
Yeah, in GENERAL a longer, not loaded antenna is better, but PLACEMENT on the vehicle is of much more importance.
More important by up to 20 dB. Measured at far field, 360 degrees, and vertically from -5 degrees to +10.
So my suggestion, based on a LOT of fairly scientific measurement is to get the antenna that is DURABLE, suits your clearance needs, and mount it as high and centered as you can.
Much of the "difference" people find in anecdotal testing is a variation in "directivity" caused by placement of the antenna on the vehicle or radiation angle. (up tilt).
Most of the antennas we have tested that are "colinear" show uptilt. OK if working repeaters on distant mountains, or skip.
Useless to have uptilt on simplex.
Our testing used very high quality test equipment and drones.