Bearcat BC246T for CB and Aircraft Mobile scanning

Status
Not open for further replies.

aircatheavy

Member
Joined
Aug 14, 2010
Messages
63
Location
33,000 ft
Hello,

As the title says, I have a BC246T and want to scan the CB and aircraft frequencies while traveling.

Is the LARSEN NMO 150/450/800 the best for this (I don't mind having more bands available)

I don't know much at all about scanning so I may ask an ignorant question..please forgive.

Also, could you give me an idea of the RANGE I could expect to get if I mount the antenna on top of a Dodge Caravan?

Finally, does mounting this antenna require drilling holes in my vehicle? (I hope not)

thanks!
 

kd8jhc

Member
Joined
Dec 29, 2008
Messages
53
Location
Cincinnati, OH
NMO means "non magnetic option" which means YES you must drill.

You probably want to look for a magnet mount or trunk-lip mount, neither of which require a drilled hole.

I'll let someone else make antenna suggestions, but the one you listed wouldn't even be my 3rd choice for what you want to hear :) ..... BTW this probably belongs in the antenna forum.

Good luck,

Jeff
kd8jhc
 

ka3jjz

Wiki Admin Emeritus
Joined
Jul 22, 2002
Messages
25,395
Location
Bowie, Md.
NMO means "non magnetic option" which means YES you must drill.

You probably want to look for a magnet mount or trunk-lip mount, neither of which require a drilled hole.

<snip>
Jeff
kd8jhc

1. Scanning CB; you're likely to be stuck on one channel a lot, simply because there's so much noise and traffic on the channel (the channel 19 trucker's channel is/used to be this way a lot). In addition, at least when I was fooling around with it 20 years ago, there are several channels that a mode is commonly used that can't be received on the 246T (ch. 16, 36-40). You likely should just try to find the busy channels in your area and create a group around it. Here is a link that lists the channel numbers vs. frequency (anything in blue is a link)

Citizens Band - The RadioReference Wiki

2. Re the meaning of NMO - not quite. I know of several manufacturers (Diamond for one) that makes NMO style magnetic mounts. If memory serves it refers to a New Motorola type thread, and has nothing to do with 'non magnetic'

You will likely need to use a mag mount antenna or drill a hole. Trunk lip mounts might not work if you don't have a wide enough lip on the Caravan to which to attach the mount.

While the Larsen would work, a better question is 'how well'?, particularly since you're trying to use it on frequencies for which it's not designed. It will work some, but probably not very well. In addition it's kinda tough to find an antenna that is widebanded enough. Efficiencies tend to suffer below 100 mhz or so simply because the antenna is too short, yet not a lot of folks would want to have a 8 foot whip on their truck. It's really hard to design such an antenna. Here are a few links to places with wideband scanner antennas, and/or reviews;

MT What's New

Mobile Antenna Comparison - InterceptRadio.com Wiki

Scanner Antennas

3. The 'Range' of an antenna is dependent on numerous factors; the frequency, height above ground of both the receiving and transmitting antenna, solar activity (in the case of freqs below 30 mhz), receiving obstacles, transmit power and terrain to name a few. This thread discusses this topic in detail

http://forums.radioreference.com/general-scanning-forum/115818-how-far-can-i-receive.html

73 Mike
 
Last edited:

KT4HX

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
697
Location
Spotsylvania County, Va
I have to admit, I have never heard of "non-magnetic option" as a meaning for NMO. However, I did run across it when I did an acronym search. It is my understanding that in the antenna industry, the accepted definition is New MOtorola mount. And no, you don't have to drill as Mike also pointed out. In fact, I have a magmount NMO mount myself with my Larsen 150/450/800 on it. In reality, given the frequency ranges you want to monitor, it would not be your best option for those two lower bands. It's not that you wouldn't pick up stuff, but your range would be somewhat limited. Of course with CB, I figure you would want to pick up the truckers and such along the route you are traveling for road condition info. As for aircraft, unless you are close to an airport, about all you might get regularly would be planes in flight. So for stuff within a few miles you would be fine, but don't expect miraculous distance for the most part.
 

KT4HX

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
697
Location
Spotsylvania County, Va
It would certainly do great for CB. As for the airband, it would probably do ok, but of course not as good as an antenna cut for that band. Are you wanting to listen to other targets as well - such and police and fire/rescue during your trip? If so, then the Larsen might be the better overall antenna. If you only want to listen to CB and the airband, then the Little Wil would likely work better for you. Just depends on what your real focus will be both on the trip and when back home. I have never used the Little Wil, so I cannot comment on it's performance with any real authority.
 

prcguy

Member
Joined
Jun 30, 2006
Messages
15,366
Location
So Cal - Richardson, TX - Tewksbury, MA
I recently tested a few scanner antennas over a broad range of frequencies and found they are quite dismal out of the range which they are tuned for. I did not specifically test the Larsen tri-band but it would be down quite a bit in performance comparing the resonant VHF hi-band to VHF air band. CB reception would be really bad.

If those are the only two bands you need I would suggest a seperate mag mount CB antenna and an NMO mag mount with whip cut to about 25" for VHF air and combine them with a Diplexer.

This would give close to the best reception you will get without drilling holes and using larger antennas.
prcguy
 

reconrider8

Member
Joined
Dec 26, 2007
Messages
2,811
Location
Eastern, NC
so waht would be a good mag mount cb antenna and a good diplexer then cause i have the tri bander and its not that good on cb but it works for the time being but i am looking for a cb whit to throw up there to work great on cb channels
 

prcguy

Member
Joined
Jun 30, 2006
Messages
15,366
Location
So Cal - Richardson, TX - Tewksbury, MA
Bigger is better for CB like maybe 4" or longer. I prefer the Antenex/Laird CW27 broad band because its over 5ft tall and still works ok on a 5" dia NMO mag mount. It also covers CB through 10m ham without tuning. See Item # CW27, Wideband Antennas on Laird Technologies nd

A Comet CF-360B Diplexer would do the job and they show up on Epay used for cheap. See NCG Company::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
prcguy


so waht would be a good mag mount cb antenna and a good diplexer then cause i have the tri bander and its not that good on cb but it works for the time being but i am looking for a cb whit to throw up there to work great on cb channels
 
Status
Not open for further replies.
Top