Vehicle antenna for the 396

[MarkEagleUSA]

There's been numerous threads regarding the use of an 800mHz portable antenna on the 396 since it offers improved 800 reception and is acceptable at 450.

Does the same logic hold true when looking for a vehicle antenna? Would (should?) a 1/2 wave 800 antenna work as well as an 800 portable?

 

[JohnWayne]

If you want a mobile antenna for your scanner, then why not just get a mobile multi-band scanner antenna? I have some that work for VHF, UHF, and 800MHz. They even work OK on lowband. You can see them at http://shop.waltel.com/catalog/index.php/cPath/10_48 .

If you are really just concerned with 800MHz, then get an 800MHz. If you want to hear all bands pretty well, then get a multi-band scanner antenna.

Jeff

 

[Al42]

On the roof or trunk it wouldn't make any difference - either one is 0dbd gain. (The half wave is the complete dipole - the quarter wave is the top half of the antenna - the car body is the bottom half.)

You might try a 2 meter/440 MHz antenna - I've had good performance with a few from VHF-lo (39 MHz) through 800 MHz. (I haven't tried MilAir yet, but it works on everything else, which really surprised me because it shouldn't.)

 

[MarkEagleUSA]

If you want a mobile antenna for your scanner, then why not just get a mobile multi-band scanner antenna?
http://shop.waltel.com/catalog/index.php/cPath/10_48

I bought the black one from you for use with my 246. However, it doesn't seem to work as well on 800 and the 396 as the 800 handheld antenna. So I was thinking about getting something like this or this.

 

[MarkEagleUSA]

the quarter wave is the top half of the antenna - the car body is the bottom half

I still can't grasp that concept of "ground" since I use a magnetic mount with a rubber boot and a handheld scanner. :?

 

[JohnWayne]

The open coil antenna or the quarterwave antenna are both good choices for 800MHz monitoring. If you don't mind the extra height, the open coil will give better performance. If you're in a strong signal area, then I would just go with the little quarter wave. Throughout the years, I've used and sold thousands of antennas, but my all time favorite antenna is still the good old quarter wave whip.

As far as the ground, it's basically like this: The the RF radiating from the antenna is capacitively coupled to the roof. The system acts like a big air capacitor with one plate being the whip and the other being the roof. Capacitive coupling is a low impedance path for high-frequency signals like your scanner hears.

The same principle is used to get the signal through the glass on glass-mount cell phone antennas. Also, if you've ever used an EZ-Tag or similar tollway express lane tag or an RFID tag, then you have used capacitive coupling.

Hope that helps.

Thanks,
Jeff