Opinion for proper upgrade for better signal.

[browdr1]

So here is the breakdown. Running from the basement, I have a pair of BCD536HP's with a D130J antenna about 25 feet up. I am 25km. (15.67Miles) from the source. But the cable between is nothing more than a RG6 TV/sat coax. Now that does go through a 12db 70-900mHz amp about 20 feet down from the antenna. Then about 75 feet to the lossless "Y" then to each scanner. And with it I have 5 bars on both units for both 800mhz and 100mhz systems I monitor. About 90% for both Service and Quality according to the scanner analyzer. I still miss simple things now and then. and I know this by how my pair of 436's pick up first. So I want to do this right. But with a budget in mind too. Suggestions??

I am thinking of moving the antenna closer by the length of the house. It would cut it in half at least for distance of scanner to antenna. Plus should I go with RS213 all the way. or is it with it to go with LMR400 most of way if I can? I may run into issue with getting through the walls cleanly and tight. ( I hear it is stiff stuff, and I cant have a loop out as the dog will chew it cause he is a dink.) Clean and tight against the wall is best. Or do I build a junction box for it. Then into the house etc. Or LMR400 to the box, then RS213 the rest of the way. Or would that make the LMR400 pointless? Also whats the best lossless way to split an LMR for two or more units? Would an amp help any more? I know there are so many options here, so thats why I'm looking for the simplest and most efficient. OR will changing all this even bring in gains?
Thank You!

 

[prcguy]

The antenna gain minus coax loss to the first amplifier then the noise figure of that amplifier determines your system noise figure and performance at the antenna height you have chosen. The amplifier will make up for much of not all the coax loss after the amp. You didn't mention what frequencies you are targeting and if its 800MHz range your Discone is probably -10dB gain right there.

Moving the amplifier closer to the antenna will improve things by the amount of coax loss you offset and that's probably not very much in your case. Going to a lower noise figure amplifier will improve things but only a few dB at the most. Raising the antenna or choosing an antenna with better performance within the frequency range you listen will probably make a more noticeable difference than anything you proposed. Your lossless splitter also has an amplifier so now you have two amplifiers in series and that could be causing some problems. You could also be overloading your amplifiers with strong FM, TV or cell site signals, which can degrade reception and filtering out interference can greatly improve reception in that case.

 

[gh6406]

Using the Amp and having 5 bars, you may be overloading (desensitizing) the 536. Are you using the stock antennas on the 436?

 

[browdr1]

I'm targeting both 100MHz and 800MHz.

Moving the amplifier closer to the antenna will improve things by the amount of coax loss you offset and that's probably not very much in your case. Going to a lower noise figure amplifier will improve things but only a few dB at the most. Raising the antenna or choosing an antenna with better performance within the frequency range you listen will probably make a more noticeable difference than anything you proposed. Your lossless splitter also has an amplifier so now you have two amplifiers in series and that could be causing some problems. You could also be overloading your amplifiers with strong FM, TV or cell site signals, which can degrade reception and filtering out interference can greatly improve reception in that case.
[/QUOTE]
My amp is as close as possible to the antenna without being outside the house. Its about 15 feet from the antenna.
There is a bit of a extra cable spooled up inline between the two, but only about 8 feet. I do have an 800Mhz specific antenna on hand, but it then limits my access to the 100MHz range.... So I figured I was doing alright with the current antenna. The fork in the road down stream is literally only that. It is a "T" in the line. Non powered non anything. I don't generally have issues receiving anything. But I've noticed variances in speed of receiving time. And I'm also wondering if that is just the actual scan speed? Or if a better cable would also help.. I'm really just trying to fine tune small amounts or receiving as I typically get 95%.

 

[browdr1]

Using the Amp and having 5 bars, you may be overloading (desensitizing) the 536. Are you using the stock antennas on the 436?

Originally I had wondered that too. But I tested without and with it in place. But it seems to be the prefect fill in of missing range/signal. And Ive never experienced ant issues or flaws. Nothing noticeable anyway. Nothing comes in to hot or distorted. Nothing seems to show any issues.

 

[browdr1]

Here is the "T" in line at the scanner end.

 

[chief21]

Here is the "T" in line at the scanner end.

That "T" connector is cutting the signal to each radio in half. The proper way to split a signal is by using a multicoupler or distribution amp with just enough amplification to overcome the losses. Too much amplification can be worse than none at all.

 

[WB9YBM]

So here is the breakdown. Running from the basement, I have a pair of BCD536HP's with a D130J antenna about 25 feet up But with a budget in mind too. Suggestions??

I am thinking of moving the antenna closer by the length of the house. Or do I build a junction box for Also whats the best lossless way to split an LMR for two or more units? Would an amp help any more? I know there are so many options here, so thats why I'm looking for the simplest and most efficient. OR will changing all this even bring in gains?
Thank You!

1. find a way to move from the basement to the upper floor to shorten your feedline length;
2. move the amp as close to the antenna as possible, before the coax run attenuates your signal ('cause otherwise you'll just be amplifying noise);
3. keep connections/junctions/splitters/etc. to a minimum; even if they're of good quality, you're still inserting losses (even minimal ones will add up if there are enough of them).

 

[MDScanFan]

I agree with prcguy’s comments. The biggest bang for the buck in your current situation is likely the antenna and height. What is the 800 MHz antenna you have on hand? Perhaps trying swapping the discone for the 800 MHz for a few days to see if you notice a difference.

Even before that...are you able to connect your radio directly to the antenna or at least close to it for a test. If you still can’t hear what you want then alternate coax, splitter, or amp will likely not matter.

 

[browdr1]

That "T" connector is cutting the signal to each radio in half. The proper way to split a signal is by using a multicoupler or distribution amp with just enough amplification to overcome the losses. Too much amplification can be worse than none at all.

Id agree with you. I think I'm on the line where it is all working just right. And I only say that because I get 5 bars service from one tower, but here we have a second slightly further than the first. and I get 4 bars from it. And I am line of sight to both.
Upon the rebuild here. I will try direct, first then look into going with a proper mulitcoupler or dirt. amp.

 

[browdr1]

This week if time allows I'll be running new cable to the new antenna location. And i will certainly try it bare first as youre mentioning. And go from there.

 

[browdr1]

1. find a way to move from the basement to the upper floor to shorten your feedline length;
2. move the amp as close to the antenna as possible, before the coax run attenuates your signal ('cause otherwise you'll just be amplifying noise);
3. keep connections/junctions/splitters/etc. to a minimum; even if they're of good quality, you're still inserting losses (even minimal ones will add up if there are enough of them).

moving to a new room or upstairs is 100% impossible. But I have begun the moving of my antenna today. Deciding weather I want to go with LMR400 or rg213. I know one is half of the other. Ive got enough rg58, But by the end of the run after mounting I may be close the the 50 foot mark, and its gonna be to lossy for my liking then.

 

[browdr1]

You have all been a big help here. I know I mickyMoused this all together a year ago to get it done. To be fair, Ive had awesome results as is. But I'd like to tie it down properly now and get the right methods in the right places.

 

[chief21]

Deciding weather I want to go with LMR400 or rg213.

FYI... LMR400 is much better for UHF and 800 than 213.

 

[browdr1]

FYI... LMR400 is much better for UHF and 800 than 213.

Im working on that right now. About to order. Wilson Electronics sells 75ft of LMR400 equal grade for $118.53 Canadian. on Amazon. I'm kinda at the point where that seems the best buy for both bang and buck. Then I see the image and it says in small print RG8U. . so now I wonder, is it just a stock image, or are the just using 8u?

 

[chief21]

LMR400 is one of many cables that are considered as "RG8 class" cables. Cables in this class are essentially the same diameter and overall structure. Using that same mind-set, numerous vendors offer coax that is "LMR400-equivalent"... similar, but not real LMR400, which is only made by Times-Microwave. Unless they have changed, Wilson usually sells a product called Wilson800, which is a less expensive RG8 class cable, but not true LMR400. You can search the web for coax loss charts. In your case, you would probably be looking for the cable with the lowest loss for your primary band of interest.

 

[prcguy]

Is the 75ft of LMR400 going between the antenna and amplifier? That's a lot of LMR400 for 800MHz and will loose almost half your signal unless that amount of coax gets the antenna 75ft higher in altitude. You don't have to worry much about cable loss after the amplifier and you can use a cheaper cable there.

 

[browdr1]

Is the 75ft of LMR400 going between the antenna and amplifier? That's a lot of LMR400 for 800MHz and will loose almost half your signal unless that amount of coax gets the antenna 75ft higher in altitude. You don't have to worry much about cable loss after the amplifier and you can use a cheaper cable there.

it only needs about 63-65 feet, But with a little wiggle room and room for expansion the extra couple feet during install. 75 feet was a number many were offering premade that worked for me. But I am open to options, what do you recommend?

 

[browdr1]

LMR400 is one of many cables that are considered as "RG8 class" cables. Cables in this class are essentially the same diameter and overall structure. Using that same mind-set, numerous vendors offer coax that is "LMR400-equivalent"... similar, but not real LMR400, which is only made by Times-Microwave. Unless they have changed, Wilson usually sells a product called Wilson800, which is a less expensive RG8 class cable, but not true LMR400. You can search the web for coax loss charts. In your case, you would probably be looking for the cable with the lowest loss for your primary band of interest.

Thats kinda what I learned last night there. And So figured I would look for RG8 too. Locally I can get RG213 which I found is the similar cable. Id be a loss of 5.4db on 855MHz 75ft.
I think thats small enough. Mind you its claiming only 32.9% Efficient.. I dont like that number however.

 

[prcguy]

3dB loss is 50% of your signal. 6dB loss is kissing away 75% of your signal. I like to keep feedline loss for scanner type use to under 1dB if possible.

Thats kinda what I learned last night there. And So figured I would look for RG8 too. Locally I can get RG213 which I found is the similar cable. Id be a loss of 5.4db on 855MHz 75ft.
I think thats small enough. Mind you its claiming only 32.9% Efficient.. I dont like that number however.