Pre-Amp Help

[inlandpatch]

I am thinking on buying a pre-amp for my scanners so i could receive further agencies but not sure on what i should buy and if it would be wise due to me living in a dense metro area. I live in Chino,CA (30 miles east of LA) I have 3 scanners (BC346XT, BCD396XT and BC125AT) all attached to a 4 Port MCA204M VHF/UHF Receiver Multicoupler, which is then attached to a discone antenna on the top of my house (all pics on my profile). What, if any, pre-amps should i look at? i am aiming on getting more of LAPD,currently only getting 3-4 channels but very choppy, more of San Bernardino System 10 aprox 24 miles away. I was thinking of buying a yagi antenna but don't really want to buy/mount another antenna on the house. Any suggestions?? Thanks!!!

 

[mark40]

http://forums.radioreference.com/sp...plitting-antenna-coax-impedance-mismatch.html

I had the same question: if you read thru this thread you'll find some solid input. Helped me a great deal.

 

[zz0468]

...I live in Chino,CA (30 miles east of LA)

You have to consider that at your location, you will be limited by terrain from much of the LA area. If there isn't any signal to start with, adding a preamp isn't going to make it magically appear.

Another thing to consider is proximity to some of the densest RF emanating from a single mountain top in the country - Santiago Peak.

I have 3 scanners (BC346XT, BCD396XT and BC125AT) all attached to a 4 Port MCA204M VHF/UHF Receiver Multicoupler, which is then attached to a discone antenna on the top of my house

With multiple scanners, it starts to make sense to put up a separate antenna, with a filter, and THEN a preamp, and use that scanner for a single band, listening in a single direction.

A wideband preamp on a wide band antenna in the shadow of Santiago Peak is a setup for failure.

What, if any, pre-amps should i look at?

In order of preference:

1. Angle Linear... IF you can get one.

2. Advanced Receiver Research.

But don't put ANY preamp on without a band pass filter. Not there.

i am aiming on getting more of LAPD,currently only getting 3-4 channels but very choppy

What frequencies? Do you know what sites you want to be listening from?

more of San Bernardino System 10 aprox 24 miles away.

More of? What do you mean? System 10 is a single site system. You're either hearing it all, or none of it. Is it just weak? In that case, a yagi aimed at Little Mountain in San Bernardino would be required. You're WAY outside it's intended coverage area. It doesn't work in Chino. It's not designed to work in Chino.

If the yagi doesn't cut it, the yagi, a bandpass filter, and then a good preamp would be as good as it gets. If there's still not enough signal, that's too bad. System 10 doesn't cover Chino.

All of the above is true for the LAPD stuff. LAPD doesn't try to cover into Chino, so whatever signal you get there is leakage. There may only be so much you can do.

I was thinking of buying a yagi antenna but don't really want to buy/mount another antenna on the house. Any suggestions?? Thanks!!!

Add antennas, filters, and preamps dedicated to what you want to hear, or forget about it. You may have to forget about it anyway, if the desired signals are just not there.

 

[prcguy]

He's also got Seirra Peak right above him at the 91/71 freeway with lots more potential RF interferance. I agree, too much of the LAPD system would be shielded by hills and a preamp without a preselector filter would not be a good idea in that area.
prcguy

You have to consider that at your location, you will be limited by terrain from much of the LA area. If there isn't any signal to start with, adding a preamp isn't going to make it magically appear.

Another thing to consider is proximity to some of the densest RF emanating from a single mountain top in the country - Santiago Peak.



With multiple scanners, it starts to make sense to put up a separate antenna, with a filter, and THEN a preamp, and use that scanner for a single band, listening in a single direction.

A wideband preamp on a wide band antenna in the shadow of Santiago Peak is a setup for failure.



In order of preference:

1. Angle Linear... IF you can get one.

2. Advanced Receiver Research.

But don't put ANY preamp on without a band pass filter. Not there.



What frequencies? Do you know what sites you want to be listening from?



More of? What do you mean? System 10 is a single site system. You're either hearing it all, or none of it. Is it just weak? In that case, a yagi aimed at Little Mountain in San Bernardino would be required. You're WAY outside it's intended coverage area. It doesn't work in Chino. It's not designed to work in Chino.

If the yagi doesn't cut it, the yagi, a bandpass filter, and then a good preamp would be as good as it gets. If there's still not enough signal, that's too bad. System 10 doesn't cover Chino.

All of the above is true for the LAPD stuff. LAPD doesn't try to cover into Chino, so whatever signal you get there is leakage. There may only be so much you can do.



Add antennas, filters, and preamps dedicated to what you want to hear, or forget about it. You may have to forget about it anyway, if the desired signals are just not there.

 

[zz0468]

He's also got Seirra Peak right above him at the 91/71 freeway with lots more potential RF interferance...

And Pleasants Peak, and depending on where he is, a couple of sites in the Chino Hills. There are a lot of areas in Chino where a scanner or rice burner amateur radio just go bananas unless they have some filtering in front of them. A preamp wouldn't stand a chance.

 

[inlandpatch]

You have to consider that at your location, you will be limited by terrain from much of the LA area. If there isn't any signal to start with, adding a preamp isn't going to make it magically appear.

Another thing to consider is proximity to some of the densest RF emanating from a single mountain top in the country - Santiago Peak.



With multiple scanners, it starts to make sense to put up a separate antenna, with a filter, and THEN a preamp, and use that scanner for a single band, listening in a single direction.

A wideband preamp on a wide band antenna in the shadow of Santiago Peak is a setup for failure.



In order of preference:

1. Angle Linear... IF you can get one.

2. Advanced Receiver Research.

But don't put ANY preamp on without a band pass filter. Not there.



What frequencies? Do you know what sites you want to be listening from?



More of? What do you mean? System 10 is a single site system. You're either hearing it all, or none of it. Is it just weak? In that case, a yagi aimed at Little Mountain in San Bernardino would be required. You're WAY outside it's intended coverage area. It doesn't work in Chino. It's not designed to work in Chino.

If the yagi doesn't cut it, the yagi, a bandpass filter, and then a good preamp would be as good as it gets. If there's still not enough signal, that's too bad. System 10 doesn't cover Chino.

All of the above is true for the LAPD stuff. LAPD doesn't try to cover into Chino, so whatever signal you get there is leakage. There may only be so much you can do.



Add antennas, filters, and preamps dedicated to what you want to hear, or forget about it. You may have to forget about it anyway, if the desired signals are just not there.

Thanks for replying and trying to help me out!

thats what i was thinking of that i would be limited because of all the hills that block me.

the frequency range would be 450.-507. is the entire LA County police freq, i know i will not be able to find an antenna with that range but i heard i could get a TV yagi antenna and use that and that would work, is this true?

what i would like to mainly listen too would be LAPD but if i could get a majority of LA CNTY that that would be great!

with system 10, it depends on what days i get reception if any and yes the system is very weak just wondering what would be the best.

and lastly yes that is what i was thinking of was just forgetting about it of course because of all the hills and don't really want to buy another antenna, just wanted to see if i could buy a pre-amp with a filter and hope it would work THANKS!!

 

[k9rzz]

Try a directional antenna and the best coax you can afford.

 

[zz0468]

...the frequency range would be 450.-507. is the entire LA County police freq, i know i will not be able to find an antenna with that range but i heard i could get a TV yagi antenna and use that and that would work, is this true?

Yes. A UHF television yagi or a corner reflector would work. Keep in mind, though, that TV "yagi" antennas are actually log-periodic antennas, at least most of them are. You can tell by the fact that they have two parallel booms, and the elements alternate from one boom to the other.

Log-periodic antennas are very broadband, but they don't have a lot of gain for their size.

what i would like to mainly listen too would be LAPD but if i could get a majority of LA CNTY that that would be great!

Determine what you can hear with a decent omni. Include things that are close to unreadable. Figure that with a decent antenna, and preamp-filter, the things you can barely hear now can probably be made to sound decent. If you don't hear it at all now, chances are pretty good that you still wont hear it after making investments in antennas and preamps.

with system 10, it depends on what days i get reception if any and yes the system is very weak just wondering what would be the best.

A separate long boom yagi aimed at Little Mountain in San Bernardino with a good 850-869 MHz bandpass filter, and an Angle Linear or Advanced Receiver Research low noise preamp.

and lastly yes that is what i was thinking of was just forgetting about it of course because of all the hills and don't really want to buy another antenna, just wanted to see if i could buy a pre-amp with a filter and hope it would work THANKS!!

Unfortunately, a better antenna is where you need to start, and based on the fact that you're interested in UHF to the west, and 800 MHz to the east, TWO better antennas are what's called for.

Once you overcome whatever artificial obstacle that prevents you from doing that, you can revisit the problem.