Antennas

[ladn]

Gotcha is having a vehicle scanner antenna really necessary? I get ham but the coverage is good in my area but I’m not sure when I travel. Any recommendations?

Only you can decide if the limited performance of having a scanner sitting inside your vehicle with no external antenna is 'good enough'. You can do that right now. Stick the scanner in your car without an external antenna and drive around and see how it performs:
1. It works well enough for you? YOU shouldn't install an external antenna on YOUR car.
2. If does not work well enough for you? YOU should install an external antenna on YOUR car.

What @mmckenna said!

 

[lcat06]

My opinion after almost 30 years of doing two way radio as a career: I will always install an external antenna for my two way radios.

Only you can decide if the limited performance of having a scanner sitting inside your vehicle with no external antenna is 'good enough'. You can do that right now. Stick the scanner in your car without an external antenna and drive around and see how it performs:
1. It works well enough for you? YOU shouldn't install an external antenna on YOUR car.
2. If does not work well enough for you? YOU should install an external antenna on YOUR car.

If you use quality name brand antenna mount, coaxial cable cut to length, coaxial connector properly installed, and a quality antenna suitable for the frequencies you want to listen to, then you will see a large improvement in scanner performance.

To me, it's a easy answer.

Okay thanks this is very helpful. How much of a performance loss would I lose if I mounted the antenna on the 4Runner roof rail (I will ground it) as compared to drilling into the roof?

 

[mmckenna]

Okay thanks this is very helpful. How much of a performance loss would I lose if I mounted the antenna on the 4Runner roof rail (I will ground it) as compared to drilling into the roof?

Probably quite a bit.

Grounding isn't the same as ground plane. Running a wire from the antenna base down to a mounting screw for the roof rails isn't going to provide the ground plane under the antenna.

If your focus is on performance and everything working as well as it possibly can, you want the permanent NMO mount.

 

[lcat06]

Probably quite a bit.

Grounding isn't the same as ground plane. Running a wire from the antenna base down to a mounting screw for the roof rails isn't going to provide the ground plane under the antenna.

If your focus is on performance and everything working as well as it possibly can, you want the permanent NMO mount.

I don’t think I will be able to drill. Is my second best option a mag mount or a roof rack mount

 

[mmckenna]

I don’t think I will be able to drill.

Any reason why?

Is my second best option a mag mount or a roof rack mount

Probably the mag mount, as that'll actually put it ON the ground plane rather than hovering above. But mag mounts are not perfect and come with their own challenges. If you can overcome the challenges with drilling the hole, that's a much better solution.

 

[lcat06]

Any reason why?



Probably the mag mount, as that'll actually put it ON the ground plane rather than hovering above. But mag mounts are not perfect and come with their own challenges. If you can overcome the challenges with drilling the hole, that's a much better solution.

I don’t want to have a permanent hole. How bad is a mag mount on the actual ground plane (the roof)? What do you mean there own challenges

 

[mmckenna]

I don’t want to have a permanent hole.

OK.

How bad is a mag mount on the actual ground plane (the roof)?

There's a tiny bit of extra loss by not having a direct attachment to the ground plane.

What do you mean there own challenges

Couple of things:
You still have to get the coax inside the vehicle. That means running it through the window or door, which can eventually damage the coaxial cable, damage the weather stripping, let water in, and/or make it easier for someone to break into the vehicle.
The lack of direct connection to the ground plane can result in the coax radiating some of the RF if the antenna is not tuned really well. That stray RF can get inside the vehicle and cause issues with electronics.
Long term, dust/grit can get under the magnet and result in scratches. Paint discoloration can be the other issue.
Hitting a tree branch/parking garage can result in the mag mount doing damage to the roof. I've seen this happen a few times with some big scratches/dents when the mount fell off the roof and hit the side of the car

They can be a acceptable solution for many if you are willing to deal with those drawbacks. For most, the drawbacks are easier to deal with than drilling the hole, and that's OK.

 

[lcat06]

OK.



There's a tiny bit of extra loss by not having a direct attachment to the ground plane.



Couple of things:
You still have to get the coax inside the vehicle. That means running it through the window or door, which can eventually damage the coaxial cable, damage the weather stripping, let water in, and/or make it easier for someone to break into the vehicle.
The lack of direct connection to the ground plane can result in the coax radiating some of the RF if the antenna is not tuned really well. That stray RF can get inside the vehicle and cause issues with electronics.
Long term, dust/grit can get under the magnet and result in scratches. Paint discoloration can be the other issue.
Hitting a tree branch/parking garage can result in the mag mount doing damage to the roof. I've seen this happen a few times with some big scratches/dents when the mount fell off the roof and hit the side of the car

They can be a acceptable solution for many if you are willing to deal with those drawbacks. For most, the drawbacks are easier to deal with than drilling the hole, and that's OK.

Thank you so much for the help. I am very hesitant between the mag mount and nmo permanent mount. If I have a firestik cb on a rago fabrication mount (4Runner) on the back left rear fender, where would be the best places on the roof to put a nmo mount for a sds100 scanner and a ham antenna? Can you link the permanent nmo mount? What are some good ham antennas is the signal stalk any good?

 

[mmckenna]

Permanent NMO mounts:
For your ham radio with a UHF connector:

3/4" NMO Hole Mount 17' RG58/U with PL-259 connector TE Connectivity MB8PS

Manufacturer: TE Connectivity; Description: The Laird MB8PS vehicle roof mount antenna installation hardware kit is for Motorola-style mobile antennas, 0 –

theantennafarm.com

For your scanner with an SMA connector:

Laird TE Connectivity MB195SMI14 - NMO 3/4" Hole Mounts SMA

Manufacturer: Laird External Antennas TE; Model #: MB195SMI14; 3/4 in Mnt 14ft LMR195 crimp SMA plug; LAIRD's MB195SMI14 all brass 0 – 1000 MHz permanent

theantennafarm.com

Doing your first permanent antenna install isn't easy. It's a big step. But once you do the first one, you'll never go back. None of the nonsense with compromise mounts, routing cable through doors/windows, etc. Will not leak if installed per the directions, and the directions are pretty easy to follow. Only challenge is that you'll need a 3/4" hole saw, but that's not a big deal:

https://www.amazon.com/DEWALT-D180012IR-IMPACT-READY-4-Inch/dp/B002LF90UI

For the amateur radio, I'm guessing you have a dual band radio?
Kind of the gold standard is this one:

Larsen NMO2/70B Premium Larsen 2m 70cm 144 440 Amateur Ham Radio Antenna Dual Band

Larsen NMO2/70B 2m 70cm 144 440 Amateur Ham Radio Antenna Dual Band Larsen

theantennafarm.com

If clearance is an issue and you want something a bit shorter, this is a good antenna:

Larsen NMO2/70SH Premium Larsen 2m/70cm Amateur Ham Radio Antenna Short Dual Band

Larsen NMO2/70SH Premium Larsen 2m/70cm Amateur Ham Radio Antenna Short Dual Band

theantennafarm.com

Larsen makes commercial/public safety antennas and these two amateur radio models will outlast your vehicle, the one after that, and you'll likely pass these down to your grandkids. I've got 30+ year old Larsen antennas. They are much more durable than the consumer/hobby grade stuff you'll find.

For your scanner, I'd recommend this antenna:

Larsen NMO150/450/758SF Tri-band Mobile Antenna covers 150-174, 430-520 & 750-870, 100 Watts, Length 16.5 in, NMO Mount, Spring Base

Larsen NMO150/450/758SF Tri-band Mobile Antenna covers 150-174, 430-520 & 750-870, 100 Watts, Length 16.5 in, NMO Mount, Spring Base

theantennafarm.com

or this one:

EM Wave EM-M43002 Tri-Band 150-162/450-490/763-870 MHz Mobile Antenna - 17.7 in - NMO - Spring Base

EM Wave EM-M43002 Tri-Band 150-162/450-490/763-870 MHz Mobile Antenna - 17.7 in - NMO - Spring Base

theantennafarm.com

I've used both of those extensively on top of full size trucks. They've hit a lot of low tree branches and are doing just fine. They'll cover VHF, UHF, 700 and 800MHz, so pretty much all the good stuff your scanner needs.

Spacing depends on how much you have available. For both of these antennas, they'll want about 18" of ground plane in all directions under them. Doesn't necessarily mean they have to be dead center on the roof, they can be offset if that's what your installation requires.

They also need to be separated by a few feet to prevent the transmitted energy from your dual band antenna from overloading the front end of your scanner.
I wouldn't worry about spacing too much from a 4 watt CB radio antenna. 4 watts isn't enough to be a problem for your radios. Keep 2 feet or so away and you'll be just fine.

Not sure exactly where on your vehicle they should go since you have the top rack to deal with. You'd want to keep a bit of spacing from that. If you don't have a sun roof, that's good. Working around those can be a challenge.

If you really wanted to go all the way, you could replace that firestick with an NMO mount CB antenna:

Larsen NMO27C CB & 10 Meter Amateur Radio Antenna NMO Mount 27-30 MHz Ham

Larsen NMO27C CB & 10 Meter Amateur Radio Antenna NMO Mount 27-30 MHz Ham

theantennafarm.com

 

[lcat06]

Permanent NMO mounts:
For your ham radio with a UHF connector:

3/4" NMO Hole Mount 17' RG58/U with PL-259 connector TE Connectivity MB8PS

Manufacturer: TE Connectivity; Description: The Laird MB8PS vehicle roof mount antenna installation hardware kit is for Motorola-style mobile antennas, 0 –

theantennafarm.com

For your scanner with an SMA connector:

Laird TE Connectivity MB195SMI14 - NMO 3/4" Hole Mounts SMA

Manufacturer: Laird External Antennas TE; Model #: MB195SMI14; 3/4 in Mnt 14ft LMR195 crimp SMA plug; LAIRD's MB195SMI14 all brass 0 – 1000 MHz permanent

theantennafarm.com

Doing your first permanent antenna install isn't easy. It's a big step. But once you do the first one, you'll never go back. None of the nonsense with compromise mounts, routing cable through doors/windows, etc. Will not leak if installed per the directions, and the directions are pretty easy to follow. Only challenge is that you'll need a 3/4" hole saw, but that's not a big deal:

https://www.amazon.com/DEWALT-D180012IR-IMPACT-READY-4-Inch/dp/B002LF90UI

For the amateur radio, I'm guessing you have a dual band radio?
Kind of the gold standard is this one:

Larsen NMO2/70B Premium Larsen 2m 70cm 144 440 Amateur Ham Radio Antenna Dual Band

Larsen NMO2/70B 2m 70cm 144 440 Amateur Ham Radio Antenna Dual Band Larsen

theantennafarm.com

If clearance is an issue and you want something a bit shorter, this is a good antenna:

Larsen NMO2/70SH Premium Larsen 2m/70cm Amateur Ham Radio Antenna Short Dual Band

Larsen NMO2/70SH Premium Larsen 2m/70cm Amateur Ham Radio Antenna Short Dual Band

theantennafarm.com

Larsen makes commercial/public safety antennas and these two amateur radio models will outlast your vehicle, the one after that, and you'll likely pass these down to your grandkids. I've got 30+ year old Larsen antennas. They are much more durable than the consumer/hobby grade stuff you'll find.

For your scanner, I'd recommend this antenna:

Larsen NMO150/450/758SF Tri-band Mobile Antenna covers 150-174, 430-520 & 750-870, 100 Watts, Length 16.5 in, NMO Mount, Spring Base

Larsen NMO150/450/758SF Tri-band Mobile Antenna covers 150-174, 430-520 & 750-870, 100 Watts, Length 16.5 in, NMO Mount, Spring Base

theantennafarm.com

or this one:

EM Wave EM-M43002 Tri-Band 150-162/450-490/763-870 MHz Mobile Antenna - 17.7 in - NMO - Spring Base

EM Wave EM-M43002 Tri-Band 150-162/450-490/763-870 MHz Mobile Antenna - 17.7 in - NMO - Spring Base

theantennafarm.com

I've used both of those extensively on top of full size trucks. They've hit a lot of low tree branches and are doing just fine. They'll cover VHF, UHF, 700 and 800MHz, so pretty much all the good stuff your scanner needs.

Spacing depends on how much you have available. For both of these antennas, they'll want about 18" of ground plane in all directions under them. Doesn't necessarily mean they have to be dead center on the roof, they can be offset if that's what your installation requires.

They also need to be separated by a few feet to prevent the transmitted energy from your dual band antenna from overloading the front end of your scanner.
I wouldn't worry about spacing too much from a 4 watt CB radio antenna. 4 watts isn't enough to be a problem for your radios. Keep 2 feet or so away and you'll be just fine.

Not sure exactly where on your vehicle they should go since you have the top rack to deal with. You'd want to keep a bit of spacing from that. If you don't have a sun roof, that's good. Working around those can be a challenge.

If you really wanted to go all the way, you could replace that firestick with an NMO mount CB antenna:

Larsen NMO27C CB & 10 Meter Amateur Radio Antenna NMO Mount 27-30 MHz Ham

Larsen NMO27C CB & 10 Meter Amateur Radio Antenna NMO Mount 27-30 MHz Ham

theantennafarm.com

Okay thank you for the help

 

[ladn]

I don’t think I will be able to drill. Is my second best option a mag mount or a roof rack mount

I use a Larsen NMO magnet mount on my 2018 4Runner for my ham antenna. It's placed just forward of the front roof rack cross rail. Works perfectly fine with either the 19" 1/4 wave antenna or the Larson NMO 2/70. I use the 19" antenna around town since it bangs a lot less in parking garages. I modified my 2/70 to add a spring just above the coil for better flexing off-road. I also use a zip tie around the coil and rack rail as I've found that (occasionally) off-road antenna oscillation causes the magnet to shift positions.

I have no opposition to doing a thru the roof antenna mount install, but I'm Leary about routing the antenna cables under the side curtain airbags and down the "B" pillars.

 

[lcat06]

I use a Larsen NMO magnet mount on my 2018 4Runner for my ham antenna. It's placed just forward of the front roof rack cross rail. Works perfectly fine with either the 19" 1/4 wave antenna or the Larson NMO 2/70. I use the 19" antenna around town since it bangs a lot less in parking garages. I modified my 2/70 to add a spring just above the coil for better flexing off-road. I also use a zip tie around the coil and rack rail as I've found that (occasionally) off-road antenna oscillation causes the magnet to shift positions.

I have no opposition to doing a thru the roof antenna mount install, but I'm Leary about routing the antenna cables under the side curtain airbags and down the "B" pillars.

Yeah that’s going to be difficult to route it. Is there any other way to route it if you went the permanent nmo route

 

[ladn]

Yeah that’s going to be difficult to route it. Is there any other way to route it if you went the permanent nmo route

Going down the "B" pillar is the shortest route. Possibly the coax could be routed back and then down the "C" pillar. I haven't seen enough information to get an accurate picture of the layout between the roof and the headliner, and I really do not want to drop the headliner to find out.

 

[mmckenna]

Yeah that’s going to be difficult to route it. Is there any other way to route it if you went the permanent nmo route

Pretty much all vehicles have side curtain airbags now and routing cable around them is a standard part of the job. You just make sure you route the cable between the roof skin and the airbag so it's not in the way if the airbag deploys.

Routing down the B pillar as @ladn suggested is often the easiest path to the center console.

 

[Ubbe]

Where I worked we had quite a few people coming in and have us drill a hole for an antenna. I believe we charged $20 or something for a 2 minute job including cleaning the underside of the roof for a good grounding. A cake or a bag of danish pastery for fika was also accepted as payment as we then didn't had to do any paperwork. The guys we had doing installations had the right tools and experience to know where on the roof that where the best place for a hole for that specific car model. Then they where told how and where they should route their coax. Best advice are to go to the experts.

/Ubbe

 

[lcat06]

Gotcha how could I make a antenna blend in paint wise I have a silver car would black be the best?

 

[lcat06]

I use a Larsen NMO magnet mount on my 2018 4Runner for my ham antenna. It's placed just forward of the front roof rack cross rail. Works perfectly fine with either the 19" 1/4 wave antenna or the Larson NMO 2/70. I use the 19" antenna around town since it bangs a lot less in parking garages. I modified my 2/70 to add a spring just above the coil for better flexing off-road. I also use a zip tie around the coil and rack rail as I've found that (occasionally) off-road antenna oscillation causes the magnet to shift positions.

I have no opposition to doing a thru the roof antenna mount install, but I'm Leary about routing the antenna cables under the side curtain airbags and down the "B" pillars.

Do you have any experience with the signal stalk antennas both the 1/2 wave and 1/4 wave

 

[mmckenna]

Gotcha how could I make a antenna blend in paint wise I have a silver car would black be the best?

Usually the antenna whips are chrome and they'll blend in well. Against a blue sky, or even a cloudy/overcast one, they blend in well.

You can get antennas with black whips, but they sometimes chip and start to look a little crappy after a while. I used to use them and stopped. I just use the chrome whips now.

 

[mmckenna]

Do you have any experience with the signal stalk antennas both the 1/2 wave and 1/4 wave

I've never used that brand.

I have used the StiCo brand whip which are the same thing, just a professional brand with a higher price.

But you really don't need those. The antennas I linked to are pretty flexible as is and I've never needed anything else, even on a full size 4x4 truck that gets off road.

 

[ladn]

Do you have any experience with the signal stalk antennas both the 1/2 wave and 1/4 wave

Sorry, but no.