Upgrading antenna and coax

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radiopro52

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Hello fellow radio hobbiests. I'm in a bit of a fix here currently. I got my scanner almost a year ago (PRO-2052), and I only used the stock antenna. But to get the best reception, I installed an outdoor antenna: (Three long planes pointing downward are circled in red)



I'm pretty sure it's the RS 20-176, cause it's look just like it. I hear it's an OK antenna, but not the best in 800 Mhz.

My other problem is that I'm using RG-58 cable. I'm going to replace it. I've heard alot of good things about LMR-400 coax, so I'm thinking of going with that. I've also heard good things about RG-6 and RG-213, but from what I've been reading here, LMR-400 seems to be the best bet.

I mainly listen to 140-160 MHz and 450-470MHz, but I'm also interested in trunking some 800MHz frequencies, which I can't do with my currenty setup. I can pick up one Motorola trunking frequency in 800MHz, but it goes in and out. The EDACS frequencies I'm trying to pick up won't come in at all.

So, my question is, shall I just try changing the coax first and see if I that'll give me good performance in 800MHz, or should I change the antenna too while I'm at it?

And one more question. What is the expected range for the average antenna in miles? I'd like an antenna that picks up frequencies as far out as possible, like 100 miles or so. If it'll put a whole in my wallet or if there's no such thing, it's not necessary.

Thanks for any help.
 

hoser147

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Defiantly upgrade the coax. There really is no magical mileage as far as range goes, it all is dependent on the terrain, the system you are wanting to listen to and other variables. Hoser
 

radiopro52

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I'm kind of in a valley. There's a couple of hills around me, so the land here isn't very flat.

By the way, the length of the cable totals 56 feet. It's 50 foot coax connected to a 6 foot jumper, also RG58. 50 feet was just a tad too short.
 

radiopro52

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Yeah, I'm pretty sure that's what I'm going to get. Comparing RG58 to the other popular coax using this calculator:

http://www.timesmicrowave.com/cgi-bin/calculate.pl

I'm currently losing at least 7.6 dB using RG58 on 800MHz. LMR-400 is only 2.1 dB loss at 56 feet.

RG-6 has 4.6 dB loss, and RG-213 has 3.6 dB loss using the same settings as above. So, I think it's pretty safe to go with LMR-400. No store in my local area sells LMR-400 cable though. I found someone on Ebay who's selling it for $1 a foot.
 

hoser147

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Take a look around on ebay and other scanner sites. There are other brands like Commcast has some on ebay might be better price but same specs. there are alot of threads on this. If you mostly listen to 800 you may want to look at different antenna's. Hoser
 

radiopro52

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Is there a difference between the Times Microwave coax and the Amphenol coax that sells for a $1 a foot? I would guess they'd be the same. Here's the Amphenol coax:

http://cgi.ebay.com/LMR-400-COAX-CABLE-LOW-LOSS-SOLD-BY-THE-FOOT_W0QQitemZ200208015434QQihZ010QQcategoryZ48704QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

As for antennas, I'd like an antenna that does great in 100MHz, 400MHz, and 800MHz. I don't listen to 800Mhz now since I can't receive them. But if there's an antenna that performs just about equaly in 100Mhz, 400Mhz, and 800MHz, that would be a good deal.
 

hoser147

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radiopro52

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I'll probably trim those branches later in the spring. They're not touching the antenna but they may be blocking some signals.

Thanks for all your help hoser147.
 

Taloniilm

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it has the connectors already installed... I just coiled the excess on my set up and zip tied it... You may even take a look at moving your antenna to different location, (away from the overhanging branches) and getting some elevation. Before you know it 75 ft will be used up !

btw, I have two of the RS 20-174, (Sputniks) fed with RG6 Quad shield and my 800 reception is 5 bars on my BCT-15, (distance from Xmiter is 26 miles). My 996 gets the LMR 400 connected to a Diamond D-130J
 

radiopro52

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Well that's a pretty good deal at about $55 with shipping. On Ebay I'd be paying almost $80 for a shorter length. So when it comes to this coax, brand name really doesn't matter as long as it's LMR-400, right?

One thing I am concerned about though. The longer the coax, the more loss you get. At 75 feet, I'd be losing almost a full dB more than if I used 56 feet of coax. So I'd rather trim the coax to the desired length, cause I want the least loss as possible for the weaker frequencies. What other tools would I need to trim it and attach that connector on the end?
 

Taloniilm

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I read on here that attaching a connector to LMR 400 can be tricky. when it was all said and done I had about 8 ft left over that I coiled up... who knows I may go higher some day. I like having that option. but yes LMR 400 is LMR 400
 
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Taloniilm

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either way you go, you'll see noticable improvement in your reception. just be sure to seal the connection at the antenna with coax wrap. a dab of dielectric grease inside the connectors will prevent corrosion too. I spent extra attention to water proofing and chaf prevention
best of luck in your project
 

radiopro52

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Hey, guys, I have one question for you. I'm going to put my antenna on another pole, not the one I have in the picture. I'm going to move the antenna to another spot on a higher telescopic pole. I'm going to dig a hole in the ground and cement it in. My question is, how deep should the hole be so that the pole won't sway in the wind very much?
 

radiopro52

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I've had this pole for a long time. I used to have a TV antenna on it, but then I took it down. But now I think it'll work great for this radio antenna so that it'll go higher.

Hoser, you don't have any suggestions on how deep the hole should be?
 
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