antenna upgrade??

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colvillegreg

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Hi guys ,new scanner is workin well! got a question-I have a couple freqs. that show about 2 bars on the screen when they come across ,all static noise.would a better antenna help this or?? The city police are about 12 miles from here, I can hear bout everything else very good.the city police have quite a bit off traffic and would be interesting to hear but just noise on this end. Any suggestions , all input appreciated thanks again
 

mmckenna

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Mobile scanner, hand held scanner, or base scanner?

Improving your antenna system will -likely- improve performance. The stock antennas that come with many scanners have always been a compromise of price and performance. Getting a better antenna with good feed line outside your home, office, or vehicle is the way to go.

Antenna height is key to coverage. The higher up you can get the antenna, the farther away your "radio horizon" is. Using high quality feed line to get the signal to your scanner without losing all of it in cable losses is important.
 

wkm

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You want to build one or buy one? The easiest to build is a dipole. I am getting good results with a OCFD even with it horizontal. I know but my attic space isn't tall enough.Homebrewed Off-Center Fed Dipole - The RadioReference Wiki

I have also tried a folded dipole with 300 ohm ladder line put inside pvc pipe held taunt with fender washers and zip ties. You could also use twin lead and a matching transformer. With around 10 bucks for 100ft of twin lead you could cut alot of antennas matched to different frequencies. Unless you are going low.
 

Blackink

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You can try moving the scanner around to different places either when your inside or outside.

The stock antenna on my BCT15X worked pretty good from inside my house but when I moved it outside and to a lower elevation, because that was where my deck was, it came in even better!

I now have an ST-2 antenna connected to it and it works great, much better then the stock antenna.
 

colvillegreg

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antenna upgrade

thanks all -the scanner is a bct15x, I have an outside antenna mounted at the peak of the roof and is approx 3-4 feet above the peak,It is a very cheap radio shack antenna that I had never used on a previous scanner. I believe it is a discone type antenna. the coax is rg58and is 50 ft long. I m up in the mountains witha lot of trees around, going higher is possible. I am very green when it comes to scanners and all the terminolgy so I probably sound like a dummy. thanks
 

n5ims

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thanks all -the scanner is a bct15x, I have an outside antenna mounted at the peak of the roof and is approx 3-4 feet above the peak,It is a very cheap radio shack antenna that I had never used on a previous scanner. I believe it is a discone type antenna. the coax is rg58and is 50 ft long. I m up in the mountains witha lot of trees around, going higher is possible. I am very green when it comes to scanners and all the terminolgy so I probably sound like a dummy. thanks
Sounds like your biggest flaw is the coax. RG-58 can eat up quite a bit of your signal, even over just 50'. Replace it with some quality LMR-400 (or better) and you'll think you're using a different antenna!
 

Blackink

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I live in Central Vermont Greg and there are mountains around me also.

So the outside antenna that is mounted 3-4 feet above the peak of your roof is the one that's giving you the 2 bars signal strength from the PD that's 12 miles away?

An inexpensive fix is purchasing an ST2 antenna from a distributor, usually around $50 and it comes with 50' of RG6 coax. It's not the greatest antenna or coax but it works better than the stock antenna that comes with the BCT15X.
Here's the one from Amazon: Amazon.com: Scanner Ant-Base 30-1300Mhz 50'Rg6 15Elm: Electronics

It's the one I use and hopefully in the future, maybe this coming summer, I can raise it up another 10' or so from where it is now.
 

cpetraglia

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With a little more info, we could give a little more help. What freqs are you trying to improve? Your RG58 is a very weak link in the antenna system. It is poorly shielded and has a lot of loss even at 50 ft. For a receive only scanner you could try using RG6U even though it is 75 ohm. Its available at any hardware store and not expensive. You will need a few adapters or rig some connections just for testing. If this helps, I would then suggest 400 series cable pre-made with the correct connectors. Naturally, your antenna may not be best for the target frequency. Get us some more info and we can give better advice.

Chuck
 

colvillegreg

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antenna upgrade

With a little more info, we could give a little more help. What freqs are you trying to improve? Your RG58 is a very weak link in the antenna system. It is poorly shielded and has a lot of loss even at 50 ft. For a receive only scanner you could try using RG6U even though it is 75 ohm. Its available at any hardware store and not expensive. You will need a few adapters or rig some connections just for testing. If this helps, I would then suggest 400 series cable pre-made with the correct connectors. Naturally, your antenna may not be best for the target frequency. Get us some more info and we can give better advice.

Chuck
thanks again for the info and help the freq that make all the noise is 154.8150,I will check into the 400 cable and get teh correct connectors.The scanner came pre programmed from scanner masterwith the freqs for stevens county ,wa.Like I mentioned the current antenna is a very inexpensive radio shack unit that I had from a previous scanner but never used.thanks - greg
 

wkm

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The ST-2 can be bought from RS with free shipping also. But like anything from Amazon we have to pay sales tax. RG58 or 59 for that matter perform poorly in the 800mzh area. I am currently using RG-6 and could instantly see a difference in the signal when I switched from rg59. Which I was using for a test because I had 50ft of it.
 

colvillegreg

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antenna upgrade

I live in Central Vermont Greg and there are mountains around me also.

So the outside antenna that is mounted 3-4 feet above the peak of your roof is the one that's giving you the 2 bars signal strength from the PD that's 12 miles away?

An inexpensive fix is purchasing an ST2 antenna from a distributor, usually around $50 and it comes with 50' of RG6 coax. It's not the greatest antenna or coax but it works better than the stock antenna that comes with the BCT15X.
Here's the one from Amazon: Amazon.com: Scanner Ant-Base 30-1300Mhz 50'Rg6 15Elm: Electronics

It's the one I use and hopefully in the future, maybe this coming summer, I can raise it up another 10' or so from where it is now.
yes when the freq 154.8150 comes over it shows 2 bars on the strength meter all the rest show 4-5 bars thanks again-greg
 

N8IAA

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yes when the freq 154.8150 comes over it shows 2 bars on the strength meter all the rest show 4-5 bars thanks again-greg
Greg, common failing of frequencies that are not on repeaters (one frequency for mobile, one for base). Better coax on that antenna should really make a difference. If you are buying at the shack, make sure that it is at least RG-6 with a couple of layers of shielding. You'll need connectors to take it from the SO-239 on the discone (TV 'F' to PL-259) and ('F' to BNC) for the scanner.
HTH,
Larry
 

mmckenna

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How long have your antenna and coax been up there? Don't rule out weather damage as an issue, although the coaxial cable is likely the root cause.

Upgrade the coaxial cable to the best you can afford. When you are installing it, take a very close look at the antenna, specifically where the coaxial cable connects. Look for any corrosion or signs of water ingress. If there is, either fix it or replace the antenna. When you install the new cable, make sure you waterproof all the external connections. Getting water inside the cable will destroy it pretty quick.

With 50 feet of RG-58, you are losing almost half your signal (on VHF band) in the coaxial cable. Upgrading to better cable will reduce that loss.
RG-6 will only lose about 1/3rd of the signal on VHF in 50 feet.
LMR-400 will result in less than 20% of the signal being lost on VHF.
 

colvillegreg

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antenna upgrade

How long have your antenna and coax been up there? Don't rule out weather damage as an issue, although the coaxial cable is likely the root cause.

Upgrade the coaxial cable to the best you can afford. When you are installing it, take a very close look at the antenna, specifically where the coaxial cable connects. Look for any corrosion or signs of water ingress. If there is, either fix it or replace the antenna. When you install the new cable, make sure you waterproof all the external connections. Getting water inside the cable will destroy it pretty quick.

With 50 feet of RG-58, you are losing almost half your signal (on VHF band) in the coaxial cable. Upgrading to better cable will reduce that loss.
RG-6 will only lose about 1/3rd of the signal on VHF in 50 feet.
LMR-400 will result in less than 20% of the signal being lost on VHF.
the antenna and coax just went up bout 2 weeks ago.sounds like a cable upgrade to the lmr 400 is the ticket,what is a good antenna to put with it??
 

mmckenna

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the antenna and coax just went up bout 2 weeks ago.sounds like a cable upgrade to the lmr 400 is the ticket,what is a good antenna to put with it??
The type of antenna you need depends on a number of things.

Most of all, what are you listening to?
"Do everything" antennas are a compromise. Discone type antennas are very popular if you are trying to cover everything your scanner will do, but Discone antennas do it with a penalty to the gain. If you just listen to UHF and VHF-High, then getting an antenna just designed for those bands -usually- results in better performance. If you are just listening to VHF, then consider getting the best VHF antenna you can afford.

I have a Telwave Discone antenna that was around $1300.00 for a remote receiver system I have at work. It works well at covering a lot of spectrum, but in no way outperforms single band antennas. Lower end/consumer grade discone antennas will work, but don't expect outstanding performance.

If you already have an external antenna, try upgrading the coaxial cable first. It's already been established that the RG-58 cable you are using is a hindrance. You need to upgrade that anyway. Try doing that first before investing money in a new antenna. You didn't say exactly which antenna you have, so it's difficult to say you need to replace it. Give the new coaxial cable a try first and see if that improves things. If it doesn't, you'll need to carefully consider which antenna you need. There isn't a "one size fits all" solution to scanner antennas.
 

colvillegreg

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The type of antenna you need depends on a number of things.

Most of all, what are you listening to?
"Do everything" antennas are a compromise. Discone type antennas are very popular if you are trying to cover everything your scanner will do, but Discone antennas do it with a penalty to the gain. If you just listen to UHF and VHF-High, then getting an antenna just designed for those bands -usually- results in better performance. If you are just listening to VHF, then consider getting the best VHF antenna you can afford.

I have a Telwave Discone antenna that was around $1300.00 for a remote receiver system I have at work. It works well at covering a lot of spectrum, but in no way outperforms single band antennas. Lower end/consumer grade discone antennas will work, but don't expect outstanding performance.

If you already have an external antenna, try upgrading the coaxial cable first. It's already been established that the RG-58 cable you are using is a hindrance. You need to upgrade that anyway. Try doing that first before investing money in a new antenna. You didn't say exactly which antenna you have, so it's difficult to say you need to replace it. Give the new coaxial cable a try first and see if that improves things. If it doesn't, you'll need to carefully consider which antenna you need. There isn't a "one size fits all" solution to scanner antennas.
thanks for the info - I have no idea whether it is VHF or UHF up here-dummy that I am in this!!and not wanting to invest that kind of cash , I will get a good coax setup and go from there- Ow do you tell if it is VHF or UHF??? thanks again
 

mmckenna

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Looking at the database for Stevens County Washington, it looks like just about everything in the way of local public safety agencies up there is on the VHF High band. That makes it easy to settle on one antenna.

Try your existing antenna first. If it's from Radio Shack, it is very likely it's already designed to work on the VHF High band.

The new coaxial cable should improve reception on it's own, based on what you already have in place. It won't solve all issues, and won't necessarily make unheard radio traffic suddenly appear, but it should improve the quality of what you are already hearing, and should do so noticeably.

Try that out first and see how it goes. Like I said above, the limitations of the existing RG-58 coaxial cable you already have are likely hampering the performance. Replacing that is an excellent first step. It -will- improve things.

If you do decide later on to try upgrading your antenna, look for a base antenna that is designed to cover the VHF High band.
A basic and rugged VHF antenna would be ideal if you are up in the mountains with snow, wind and the chance of falling branches damaging your antenna. Since installing antennas is a dangerous job, it makes some sense to do it right the first time. Some low cost rugged VHF antenna suggestions:
http://www.theantennafarm.com/catalog/laird-tech-crs150-4103.html
http://www.theantennafarm.com/catalog/browning-br-6050-3570.html
http://www.theantennafarm.com/catalog/tram-1487-1576.html
http://www.theantennafarm.com/catalog/laird-tech-crx150-4120.html
Another option would be a basic dual band amateur radio antenna. It would work just fine for monitoring:
http://www.theantennafarm.com/catalog/diamond-x50a-4869.html

But, most of all, get some good coaxial cable in place first. You can purchase it in custom lengths with the correct connectors on the end to match your antenna/radio:
http://www.theantennafarm.com/catalog/times-mic-lmr-400-1471.html
 

psdavidson

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Im reading in this post that the limits of the RG58 cable. i was going to make the ocfd anntenna and use RG6 quad shield cable. how far can I go with out ill affects? can I run 100 feet? what would max be?

Patrick
 
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