Newbie antenna question

[dyrtjunkie]

Would having two Larsen NMO150/450/800 Tri-band Antenna's on my trunk work better than one?

 

[W6KRU]

Yes.















For two scanners. Maybe. Check the stickies at the top.

 

[dyrtjunkie]

two Larsen tri-band to one BCT15

I have a BCT15 and am pretty new to scanning. I mainly want to track the PD (using the close call feature). I would have both antennas hooked up to the BCT15 (to try to get a clearer,not stronger, signal). Do you still think it would be a good idea?

Also, what do you think about the Low Profile Antennex (1in w by 3in h) antennas? Should i get one?

 

[rvictor]

I have a BCT15 and am pretty new to scanning. I mainly want to track the PD (using the close call feature). I would have both antennas hooked up to the BCT15 (to try to get a clearer,not stronger, signal). Do you still think it would be a good idea?

Also, what do you think about the Low Profile Antennex (1in w by 3in h) antennas? Should i get one?

I think that if you read the sticky at the top of this forum you will see that unless you really know what you are doing the idea of two antennas for one scanner is not likely to be worthwhile. And even then, there is considerable debate about how much benefit there is from this.

It would be helpful if you were to describe your present antenna and what frequencies you want to listen to. How is the present reception with that antenna? Then responses might be more helpful.

Dick

 

[NorCalDiesel]

Well, not to hijack the thread, but what if you wanted to generally listen to 40 through 800 MHz using a BCT15 as you drive all around Northern Ca. Focusing primarily on CHP, Pol, Fire/EMS. And you already have a crappy glass mount. So you went ahead and optimized your programming to include only what you generally want to monitor. You feel you have done a good job getting the systems in that you want, but you still lack a good antenna. You now, based on reading threads in this forum as well as that "sticky" above decided that a Larsen NMO150/450/800 is your antenna. Is that the best possible antenna for this application, or would using two mounted as the OP originally asked an even better solution?

 

[rvictor]

Well, not to hijack the thread, but what if you wanted to generally listen to 40 through 800 MHz using a BCT15 as you drive all around Northern Ca. Focusing primarily on CHP, Pol, Fire/EMS. And you already have a crappy glass mount. So you went ahead and optimized your programming to include only what you generally want to monitor. You feel you have done a good job getting the systems in that you want, but you still lack a good antenna. You now, based on reading threads in this forum as well as that "sticky" above decided that a Larsen NMO150/450/800 is your antenna. Is that the best possible antenna for this application, or would using two mounted as the OP originally asked an even better solution?

I'm not located anywhere near your area, but from the database it appears that CHP is primarily on 39-42MHz and I'd therefore question whether that antenna was going to optimize your ability to hear them. I'm not sure what will best cover the range from 39-800MHz.

On the question of adding an additional identical antenna, my reading of the sticky leads me to the conclusion that for most people the answer is "no". It appears that under some circumstances someone very knowledgeable about antenna theory may be able to obtain advantages from two antennas with one scanner, but that most people lack the technical expertise to make that happen.

If others disagree with my conclusion, I'm sure they will chime in and correct me.

Dick

 

[NorCalDiesel]

Thanks for the response. I do pick up some CHP transmissions on and around 42.6 MHz using the glass mount I currently have installed. But I too question whether the Larsen would work best. However, it is better than what I have now. I really wish there was a better option for the 30 - 40 range in combination with the 150/450/800 range. Even something that resembles the AOR SA7000, but on a mobile scale. I would consider that a great option.

BTW, I agree the sticky is more of a disagreement that swings towards the "no" column

 

[prcguy]

Some early 800MHz equipment and some cell phones had a "diversity" antenna option where you could attach two similar antennas to minimize flutter or picket fencing caused by reflected signals arriving out of phase at one antenna. Generally these radios had two RF front ends with a common LO. In other words dual antennas for mobile use go far beyond just combining two antennas outside the receiver and they were not used to increase signal strength.
prcguy

 

[dyrtjunkie]

All I have is the supplied base extender antenna that came w the Uniden BCT15. I want to figure out I want to emulate what the PD has on their cruisers, which are three low profile antennas. Each are 1" wide and 3" tall and are NMO (New Motorola) mounted on the trunk. (I suppose one tuned for 150mhz, one for 450mhz and one for the 800mhz range) or at least that is what I am assuming. What is the best website to buy these low profile antennas? Or should I just buy the Larsen 150/450/800 and call it best results for the lease amount of trouble?

 

[dyrtjunkie]

I want to listen to Georgia State Patrol (150mhz) County PD (800mhz)

 

[rvictor]

All I have is the supplied base extender antenna that came w the Uniden BCT15. I want to figure out I want to emulate what the PD has on their cruisers, which are three low profile antennas. Each are 1" wide and 3" tall and are NMO (New Motorola) mounted on the trunk. (I suppose one tuned for 150mhz, one for 450mhz and one for the 800mhz range) or at least that is what I am assuming. What is the best website to buy these low profile antennas? Or should I just buy the Larsen 150/450/800 and call it best results for the lease amount of trouble?

You mention three 1" wide and 3" tall antennas. That size would be about right for 800 MHz, but too short for 150 MHz and 450 MHz antennas. Your assumption of how they are tuned seems unlikely to be correct. In any event, emulating what they have on their cruisers may not lead to optimal results unless you are also using the same radio or radios that they are using. Those three antennas may well be connected to three separate radios. As has been repeated a few times in this thread, your use of more than one antenna per scanner is not a good idea.

Since in your next post you indicate that you want to listen to 150 and 800, I'd buy ONE Larsen 150/450/800.

Of course if you are insistent on optimizing your setup with three antennas, you could buy three separate antennas and two more scanners.

Dick

 

[N_Jay]

They are probably those silly "Phantom" antennas.

They work a little better than crap, but with many public safety systems being designed for portable coverage they are all a mobile needs.