"Safest" amp antenna for chasing

[Jeff Hawkins]

I'm looking into adding an amp/antenna boost to my UM175 Verizon data card (based on responses to a post I made last fall), and was reviewing other threads about these things. In that reading, I also looked at maximum signal's website, where they offer different kinds of antennas to use.

I've done some reading about amps and antennas when chasing in remote areas, and in all the reading, I wasn't able to find an answer to the question of: what kind of antenna (magnetic roof mount, in-car mount, wireless, etc.) would give the least risk for a lightning strike, in other words, which would be the safest? I would guess the in-car kind would from what I've read (it has the lowest profile), but I'm curious what others here might think.

Should this even be a concern, as a real risk? Or is it overblown?
If using an 'in-car' antenna, is the signal compromised in rural areas, compared to the magnetic external mount antenna?
If you do use a magnetic mount antenna, how do you 'ground' it to the metal of the car with a lightning suppressor?
Or how do you go about doing DC bonding of the car?

Obviously, I'm thinking safety and minimizing hazards to self and equipment here. Thanks for any thoughts/replies in advance.

 

[Dave Marshall]

I wouldn't really sweat the lightning risk. I have a 14' vertical whip on my truck for HF ham radio use and I've yet to take a direct strike in 6 years. My overhead clearance with that thing is more than 15' when it's upright. Vehicles aren't hit very often, but when they are, whether there is an antenna present isn't going to make much of a difference. It's possible the antenna could ensure that your cell modem bites it, but it's unlikely that much else would be damaged.

If you're really concerned about lightning, a model that mounts directly to a permanent vehicle-body mount would provide better grounding and some limited protection. Lightning arrestors meant for cellphone frequencies are either very expensive, or very worthless. At such high frequencies, manufacturing tolerances must be exceedingly high to avoid an unacceptable level of signal loss.

In-car antennas will always be out performed by external antennas. Particularly at the very high frequencies used by cellphones, the vehicle body is going to have a severely detrimental effect on the radiation pattern of the antenna. You'll get nulls and lobes in an unpredictable pattern, not to mention the outward attenuation caused by the metal that surrounds you.

I would personally recommend the Wilson "Trucker" series of antennas. I run one and have had excellent results.

 

[Gordon Spencer]

a mag mount antenna grounds itself when mounted on the metal body of a vehicle. Use of a lightening suppressor on a 13 inch mag mount antenna is really overkill . You should be fine without one . The Cyfre 13 inch mag mount antenna actually outperforms Wilson trucker antennas as many users on these forums who have used both will tell you.

I'm looking into adding an amp/antenna boost to my UM175 Verizon data card (based on responses to a post I made last fall), and was reviewing other threads about these things. In that reading, I also looked at maximum signal's website, where they offer different kinds of antennas to use.

I've done some reading about amps and antennas when chasing in remote areas, and in all the reading, I wasn't able to find an answer to the question of: what kind of antenna (magnetic roof mount, in-car mount, wireless, etc.) would give the least risk for a lightning strike, in other words, which would be the safest? I would guess the in-car kind would from what I've read (it has the lowest profile), but I'm curious what others here might think.

Should this even be a concern, as a real risk? Or is it overblown?
If using an 'in-car' antenna, is the signal compromised in rural areas, compared to the magnetic external mount antenna?
If you do use a magnetic mount antenna, how do you 'ground' it to the metal of the car with a lightning suppressor?
Or how do you go about doing DC bonding of the car?

Obviously, I'm thinking safety and minimizing hazards to self and equipment here. Thanks for any thoughts/replies in advance.

 

[Gerard Jebaily]

a mag mount antenna grounds itself when mounted on the metal body of a vehicle. Use of a lightening suppressor on a 13 inch mag mount antenna is really overkill . You should be fine without one . The Cyfre 13 inch mag mount antenna actually outperforms Wilson trucker antennas as many users on these forums who have used both will tell you.

Does this apply to those of us that have numerous other antennas on our roofs as well as other equipment such as a weather station? Ive been a bit concerned that my little cyfre mag mount cell antenna is being towered over by my larger 2M whips and things and that my radiation pattern is very irregular and not as effective as the taller trucker style antenna would be.

 

[Dave Marshall]

A magmount antenna isn't actually grounded electrically directly through the car body. From the perspective of a DC power source, it's actually grounded through the coax shield to the radio, which is grounded through its negative power lead. RF is coupled capacitively from the antenna through the vehicle paint to the car body. Only RF sees that path to the car body though. DC current can flow through the paint, but only if it has a high enough voltage to cause break-down (like lightning), and only if another path with lower resistance doesn't exist.

Gerard, yes, antennas in close proximity to one another, even those feeding different devices, will interact with each other in some manner. With frequencies as high as the 800/1900MHz bands that modern cellphones run on, that effect is amplified compared to say a CB or 2 meter antenna. The effects may be dramatic, or relatively minor, depending on many variables. It is safe to assume though that you do have a few 'shadows' in your radiation pattern. The best solution isn't necessarily height as much as it is distance. This is tough for chasers to cope with because of limited real estate on a vehicle, but ideally your cellular antenna should be at least 2-3 wavelengths away from any other antenna. For 800MHz, 3 wavelengths would be about 3.5 feet. If most of your antennas are on the vehicle roof and/or trunk, a hood lip mount might not be a bad idea for your cellular antenna.

 

[Mikey Gribble]

I actually have this amp from Maximum Signal and just bought the adapter to hook it up to the verizon 175 air card. https://www.maximumsignal.net/store/product.php?productid=16172&cat=1&page=1

It is a direct connect antenna. I got that instead of the wireless one because Gordon told me that you have to have a direct connect amp to boost both the speed and signal with an air card. With the wireless you just get a signal boost. I've never used it before if you are wanting to buy one I might consider selling it. I will probably keep it though because I like to have back ups for most of my equipment when I'm out chasing. I already have a Wilson wireless amp that works great so I always just use that one. Personally I like Wilson better. That or if you aren't going to buy one for a couple weeks I will let you know how well it works with that air card after I get out chasing next. I'm anxious to see if it really is much better using that over a wireless amp.
This is the wireless wilson unit I have btw http://www.wilsonelectronics.com//ViewProduct.php?ID=127
It is worth every penny IMO. The difference it makes is amazing.

 

[Lanny Dean]

A magmount antenna isn't actually grounded electrically directly through the car body. From the perspective of a DC power source, it's actually grounded through the coax shield to the radio, which is grounded through its negative power lead. RF is coupled capacitively from the antenna through the vehicle paint to the car body. Only RF sees that path to the car body though. DC current can flow through the paint, but only if it has a high enough voltage to cause break-down (like lightning), and only if another path with lower resistance doesn't exist.

Dave, your above statement is not entirely accurate. You have neglected to include that most radios and receiver equipment have a "floating" ground chassis. That is, there is no direct contact from the negative lead to chassis itself. This is why on some equipment there is a single screw marked with a ground symbol.

Lan

 

[Gordon Spencer]

I stand by my statement that a less expensive amplifier is much better for data than wireless amplifier units. Data signals are transmitted in a constant stream while voice signal is transmitted in what are called micro bursts. Wireless amplifiers retransmit the signal in the same manor a voice signal is transmitted. While a wireless amplifier may increase your RF signal strength to your data device , Your upload and download speeds can be adversly affected by receiving the signal in microbursts . That why it is much more effective to use the less expensive direct connect amplifier for data than a more expensive wireless amplifier. I am not adverse to selling wireless amplifiers (Cyfre has good ones), just not for this purpose because upload and download speeds are the ultimate goal when amplifying a data transmission.
My engineers assure me the new line of wireless amplifiers we will be launching soon will overcome these obsticles . But I will not believe it till I test for my self and I have other users whose results I trust, test as well.

I actually have this amp from Maximum Signal and just bought the adapter to hook it up to the verizon 175 air card. https://www.maximumsignal.net/store/product.php?productid=16172&cat=1&page=1

It is a direct connect antenna. I got that instead of the wireless one because Gordon told me that you have to have a direct connect amp to boost both the speed and signal with an air card. With the wireless you just get a signal boost. I've never used it before if you are wanting to buy one I might consider selling it. I will probably keep it though because I like to have back ups for most of my equipment when I'm out chasing. I already have a Wilson wireless amp that works great so I always just use that one. Personally I like Wilson better. That or if you aren't going to buy one for a couple weeks I will let you know how well it works with that air card after I get out chasing next. I'm anxious to see if it really is much better using that over a wireless amp.
This is the wireless wilson unit I have btw http://www.wilsonelectronics.com//ViewProduct.php?ID=127
It is worth every penny IMO. The difference it makes is amazing.

 

[John Wetter]

I see my first response was stricken from the record, but yes, your 'safety' issue for lightening is overblown. An antenna isn't going to put you at an appreciable higher risk.