External Antenna for 396XT

[1150RT-P]

Once again, I have probably a pretty simple question, but as I am new to all this, a little help would be appreciated.

I will be installing a 396XT in my personal vehicle this summer to listen to Public Safety and Aviation. I am looking for an external antenna to mount on the top of my vehicle.

From my research (no much at this point, sorry), It seems I'll want access to 118.xxx up to the high 800.000 frequencies. I am in Los Angeles, if that helps.

Do I need anything special for this? The lower profile the antenna, the better.

 

[4phun]

Once again, I have probably a pretty simple question, but as I am new to all this, a little help would be appreciated.

I will be installing a 396XT in my personal vehicle this summer to listen to Public Safety and Aviation. I am looking for an external antenna to mount on the top of my vehicle.

From my research (no much at this point, sorry), It seems I'll want access to 118.xxx up to the high 800.000 frequencies. I am in Los Angeles, if that helps.

Do I need anything special for this? The lower profile the antenna, the better.

Why advertise you have a radio if you do not have to?

External antenna's make it more likely a passing opportunity thief will target your vehicle.

 

[colby4601]

That's why he said the lower the profile, the better.....

 

[1150RT-P]

From what I understand, you almost *have* to have an external antenna when scanning from a car, although I could be wrong. I would very much prefer not having anything on my car, but you have to pay to play right?

 

[KE5BCP]

Valor PMM3B Scanner Antenna

 

[1150RT-P]

Thats more or less exactly what I'm looknig for ..... but is there one that is less than "13.5 inches tall"

 

[nanZor]

An external antenna is ideal, but depending on where you go in Los Angeles, you may not want to advertise the fact that you *might* have a radio in the car. Even though you take the 396 with you, it might not stop someone from breaking in and and trying to look for it anyway. Just a thought.

If your windows aren't tinted with metallic film, and even better if you have a sunroof, the systems you want to listen to might be strong enough to allow you to enjoy scanning, even if it isn't the perfect setup.

For in-car use, I prefer the extremely thin flexible whips. The very small Diamond SRH519 and 518 have been mentioned. You could also look into a slightly larger yet still extremely thin and light Diamond SRH320A. The SRH77CA is also a good choice, although it is a bit beefier.

While you are trying to decide on the external, just do what you gotta' do. You might be surprised going stealthy.

 

[1150RT-P]

Sir,

Thank you for your detailed reply.

It sounds like you're referring to theft when you mention "where you go in LA" ... I live in a good area, and my car isn't parked anywhere for very long where I would worry about that. If I was worried, it wouldn't be too hard to throw a magnetic antenna in the car while parked.

I do have tinted windows (expensive tint, not sure if metallic?), and no sunroof in the primary car I'll be using this setup in. (my other car does have a sunroof, but i will not be doing a "hard" installation in that vehicle).

I really like the idea of a SMALL (2-4") magnetic base antenna .... that will pickup the frequencies I need. Surely, such a product exists?

 

[4phun]

Again a small mag mount doesn't equate to quality. Lacking quality means any 'gain' in RF level you have from a tiny antenna external is eaten up by the coax.

A decent antenna cut for the band right on top of the scanner is a more flexible solution. You are not trying to transmit but to receive only. For scanning I carry multiple scanners and use flexible antennas designed for 800 MHZ. Works for me in monitoring P25 systems beyond the counties they are located in while driving in a car.

I use the same mount for the iPhone to hold the radios.

BTW did you know you can follow scanner traffic on the iPhone with an iPhone scanner application?
Works really nice in some locations.
That is an incredible stealthily way to follow the police.

 

[1150RT-P]

So, you're saying that the longer the coax from the antenna to the radio, the more "loss" occurs?

I suppose i'll try my luck with a fixed antenna for now.

 

[rvictor]

So, you're saying that the longer the coax from the antenna to the radio, the more "loss" occurs?

Yes, but getting a decent antenna outside the metal car body will still produce dramatic improvements. It's just best to avoid unnecessary coax length and to use good quality coax to minimize the losses. In a vehicle installation the coax runs aren't all that long and the losses aren't all that great compared to the improvement to be gained by using a decent antenna rather than the rubber duck that comes with a portable scanner. If you have metallic coated windows, the improvement will be even greater.

And, yes, you could use an antenna that's 2"-4" high, but it isn't going to be as good as something bigger for the frequencies below 800 MHz. When it comes to antennas, there really isn't any free lunch.

Dick

 

[1150RT-P]

My installation would call for around 3' of coax, if not less.

 

[bee]

The pmm3b is a very good low profile mag mount antenna, if you can find one. If not try the ks3. These are about 13 inches long, and are black.

 

[rvictor]

My installation would call for around 3' of coax, if not less.

I'd consider the coax loss irrelevant with that short a run. If you want to calculate how irrelevant,

Coax Calculator

Dick