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Need expertise on choosing & deciding Coax Cables

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CorwinScansNM

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#1
I am looking for some well known & good advice from experienced people who know Coax Cables inside & out as well as which types are good & bad for receiving purposes. I only recieve on a digital public safety scanner & do not transmit out at all. I am looking for good quality signal receive coax cable to receive the clearest & most possible radio frequency transmission signals from my local public safety agencies from my outdoor scanner antenna to my digital scanner. My Coax Cable length is going to be 20 to 25 feet long & no longer. I have been looking on the Internet for quite some time today & am at a stand still as to what is the best or recommended for my use out of my choices that I have chosen & found but not purchased yet.

What I have found & am considering is:
RG-6 (KabelDirekt Digital) Coaxial Audio Video Cable,
RG-11 (THE CIMPLE CO) triple shielded High Definition Coax Cable,
RG-213,
RG-214,
and
LMR-240
 
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#2
Out of all those, the RG-11 is going to give you the least amount of loss.

Less loss means more signal gets to your radio.
The RG-213, RG-214 and LMR-240 all score pretty close together. RG-6 is a bit worse. However, that will all vary depending on the exact construction of the cable.

However, at 25 feet, it's unlikely you would really be able to hear the difference between them. You are looking at fractions of 1 dB between all of them.
Since connectors are important, consider what it takes to PROPERLY install a connector on the cables. Will that connector match your antenna/radio, or are you going to need to add adapters and additional loss? If you have to pay someone else to put the connectors on, then take a close look at all the costs.

Personally, for ease of connector installation, costs, etc. I'd probably go with the RG-6. It'll have slightly more loss, but unless you are really, really on the fringes of coverage, you'll likely never be able to hear the difference.

If you were running longer cables, it gets a bit more important, but 25 feet isn't much, even at 800MHz.
 
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#3
It would be nice to know what kind of antenna the OP is gong to use. If its a 50 ohm rated Discone or similar and with the maximum length of 25ft I would recommend LMR240 for its small size, ease of routing and low loss. If the antenna was designed for 75 ohms like a Scantenna I might use RG-6 or RG-11.

I noticed a particular RG-11 listed by the OP with triple shielding. For scanner use, when you need 75 ohm coax there is no reason to use anything but single shield RG-6 or RG-11 designed for CATV or satellite use because its actually double shielded with 100% foil and a braid. Double or triple shield buys you nothing for scanner use, same loss and below 1GHz negligible improvement in shielding over CATV/satellite rated cables.
 
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#4
after switching over to lmr400 from rg8x i was amazed at how better my reception was especially 800mhz even at 25 or 30 feet you will still have some loss...you dont want buyers regret....IMHO
 

Ubbe

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#6
Go with RG6. The 4-5 times higher costs of the other coaxes doesn't justify the fraction of a dB you'll gain. The same goes for 50 versus 75 ohm. I beleive it was a 0.2dB difference IF your scanner actually has a matching impedance and IF the antenna also keeps it impedance fairly constant over the frequency range you receive.
http://forums.radioreference.com/un...ront-end-filter-measurements.html#post2942675
http://forums.radioreference.com/sc...-off-center-antenna-question.html#post2967130

/Ubbe
 

CorwinScansNM

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#8
after switching over to lmr400 from rg8x i was amazed at how better my reception was especially 800mhz even at 25 or 30 feet you will still have some loss...you dont want buyers regret....IMHO
How long was your cable run length from your antenna to your receiver?
 

CorwinScansNM

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#9
Feedline Loss In DB Per 100 Feet Chart

Just found & discovered this useful Coax Cable chart online showing all different types of Coax Cables & their DB losses per 100 feet. Since I am only going to be running a 20 to 25 foot Coax Cable from my receiving scanner antenna to my digital scanner, I'm simply dividing the DB loss numbers by 4 to get the DB loss ratio for 25 feet of Coax Cable. This chart is pretty helpful & recommended for others to look at & use as well.

Enjoy!
Coax Attenuation Chart
 

ChrisABQ

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#10
Over the last 3 years, I have used RG-8, RG-6, LMR-240 and RG-58. I know some people on here will disagree, but I have exhuastedly tested these 4 cables. The MOST sensitive is the Radio Shack Brand RG-58. It has a solid copper core and copper shielding that have given me more distance and clarity than the others. Each hobbiest's situation and geographic situation is different, but this is what I have found myself. If your run is under 50 feet, I would highly recommend it. Do not be fooled by other brands, it must be the Radio Shack brand.
 

CorwinScansNM

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#11
Over the last 3 years, I have used RG-8, RG-6, LMR-240 and RG-58. I know some people on here will disagree, but I have exhuastedly tested these 4 cables. The MOST sensitive is the Radio Shack Brand RG-58. It has a solid copper core and copper shielding that have given me more distance and clarity than the others. Each hobbiest's situation and geographic situation is different, but this is what I have found myself. If your run is under 50 feet, I would highly recommend it. Do not be fooled by other brands, it must be the Radio Shack brand.
Wow!! I would never think or expect that from a store brand coax cable especially RG-58 with all of the bads & negatives that I see & read on the Internet about that type of Coax Cable. I was not even considering RG-58 Coax Cable especially after looking at the DB loss chart & seeing the DB signal loss numbers for RG-58. I am not sure that I can convince myself to buy & try it but thanks for the heads up & info on the Radio Shack Brand RG-58 Coax Cable.
 
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#13
Just found & discovered this useful Coax Cable chart online showing all different types of Coax Cables & their DB losses per 100 feet. Since I am only going to be running a 20 to 25 foot Coax Cable from my receiving scanner antenna to my digital scanner, I'm simply dividing the DB loss numbers by 4 to get the DB loss ratio for 25 feet of Coax Cable. This chart is pretty helpful & recommended for others to look at & use as well.

Enjoy!
Coax Attenuation Chart
This is a little easier:
Coax Loss Calculator | KV5R.COM
 

Ubbe

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#14
I would say that if you get better reception using a coax with more loss, you probably have some overload problem from strong signals that de-sense your receiver and adding attenuation solves that problem.

I always recommend a variable attenuator between scanner and coax when using external antennas, with our without amplifiers. You select a constant weak and noisy signal and add attenuation to check if the noise increase or decrease. Almost all scanners use wide filters that let the whole frequency band through to the first amplifier in the scanner and that will in many cases result in saturation and you loose sensitivity when using a good external antenna.
http://rfelektronik.se/manuals/Datasheets/Coaxial_Cable_Attenuation_Chart.pdf

/Ubbe
 
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#15
Belden 9913

I have had excellent experiences with Belden 9913. It is not a flexible coax, its stiff and a pain the paa-toot to put connectors on but wow, there is very little signal loss. Its pricey but you won't be replacing it anytime soon. I put my last 9913 up 15 years ago and its still going gang-busters. When everything went over to P25 it proved its worth. I do check connectors and seals on the connectors every years. Good luck and hope this helps. EA
 
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#16
75 ohm is always superior for receive.
.....
50 ohm coax only exists for transmitters.
.......
RG6 is way more than needed for your application.
......
 

CorwinScansNM

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#17
75 ohm is always superior for receive.
.....
50 ohm coax only exists for transmitters.
.......
RG6 is way more than needed for your application.
......
Thank-you, Appreciated.

I will most likely go with a higher quality RG-6 or Tri-Shielded RG-11 Coax cable & then add a N-Type Male to F-Type Female Antenna RF Adapter to my antennas connection base.
 

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CorwinScansNM

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#19
75 ohm is always superior for receive.
.....
50 ohm coax only exists for transmitters.
.......
RG6 is way more than needed for your application.
......
Only one concern with going with the RG-6 or the RG-11 Coax Cable is the (mismatch) being that my Discone Antenna is 50 Ohm & those 2 types of Coax Cable are 75 Ohm? But then again, I am only going to be (receiving) from my antenna to my receiver & not transmitting out at all ever.
 
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#20
If you are using a Uniden BCD536HP, and it will be generally the same with any scanner, you have 40 ohm impedance in the scanner at 750MHz and 115 ohm at 800MHz and 20 ohm at 850MHz. You don't have to bother with impedance matching in antenna, coax and connectors when dealing with scanner equipment.

/Ubbe
 
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