Coax Loss

[fredg]

OK, I know this horse has been beat to death, but let me give it another whack...

Using this site: http://www.ocarc.ca/coax.htm

I have this data:

Belden 8215 RG-6A 50 feet - 460MHz loss=3.185
Belden 9258 RG-8X 50 feet - 460MHz loss=4.201

Belden 8215 RG-6A 50 feet - 155MHz loss=1.76
Belden 9258 RG-8X 50 feet - 155MHz loss=2.118

Questions:
Is this the same RG-6 that they sell at Walmart for $19 for 50 feet?
My RG-8X is marked: PRO8x Low Loss Mini 8 is the same as the Belden 9258?
Will I even notice the loss difference here?

I have some LMR400 for my main antenna, but want to put up another antenna. I already have the RG-8X and I am trying to figure if it worth my time to sell it off on eBay and buy the RG-6 or just use the RG-8X.

Based on the loss chart I should just use the RG-8X....

What to you guys think?

 

[n5usr]

Do you know who made the coax? There are some manufacturers who are reproducing the "standard" well, and some who are -- well -- much more lax about it. Radio Shack is typically a great example of a vendor with absolutely LOUSY coax that wouldn't conform anywhere near the standard specs.

I'm no fan of Wal-Mart, and would assume their coax is pretty close to junk, but a quick search suggests they are selling Philips brand which I would initially think is decent... I couldn't find any reference for your "PRO8x Low Loss Mini-8" though.

Assuming both conform to the Belden specs, I would definitely use the RG-8X. 1dB at 460 MHz is almost certainly not going to be noticed, and sure isn't worth the hassle of selling off one coax to buy the other.

 

[fredg]

All I got is the "PRO8x Low Loss Mini 8" so I have no clue as to the maker. It was sold to me by Scanners Unlimited so I would expect it is decent quality....

Wait...

I checked the bag it came in.. it has a part number of PP8X50, a Google search shows Procomm as the possible manufacturer

Found it:

http://www.westcoastmall.net/procomm-rg8x-cable-pl259s/2310/p

 

[Dee_Dee_Dee]

I use LMR cable for everything. for the house it's LMR-400 at a Minimum, for the mobile i use the thinner LMR coax.

but then my friend designs and builds cell sites for a living. he can get me any form of LMR coax in any length i desire

 

[zz0468]

Is this the same RG-6 that they sell at Walmart for $19 for 50 feet?

No.

My RG-8X is marked: PRO8x Low Loss Mini 8 is the same as the Belden 9258?

No.

Will I even notice the loss difference here?

Quite possibly. Belden very clearly marks their cable. Unknown brands have unknown loss characteristics. There frequently isn't an identifiable manufacturer on cheap coax because there's nothing to be proud about.

I have some LMR400 for my main antenna, but want to put up another antenna. I already have the RG-8X and I am trying to figure if it worth my time to sell it off on eBay and buy the RG-6 or just use the RG-8X.

Who in their right mind would buy a length of RG8X on eBay? It's crappy cable intended for the CB market. Throw it away and get something decent.

Based on the loss chart I should just use the RG-8X....

Huh? The loss chart shows RG-8X to be lossier than RG-6. Why would you decide to use the lossier cable?

 

[fredg]

Quite possibly. Belden very clearly marks their cable. Unknown brands have unknown loss characteristics. There frequently isn't an identifiable manufacturer on cheap coax because there's nothing to be proud about.

I found the brand, Procomm, seems like a fairly big manufacturer after some Google searches

Who in their right mind would buy a length of RG8X on eBay? It's crappy cable intended for the CB market. Throw it away and get something decent.

There are several people selling RG8X on eBay.

Huh? The loss chart shows RG-8X to be lossier than RG-6. Why would you decide to use the lossier cable?

The loss is actually not very much from what I can see and would probably not be noticed. And I already have some brand new unused RG8X which I rather not just throw away.

 

[kb2vxa]

Like the director said, can the dialog and cut to the chase. Off brand or oddly marked with "pro" or some other nonsense coax is like a box of chocolates, you never know what you're going to get. That RG-6U quad shield coax from Wal Mart is the best you can get, plain old RG-6 from anywhere is garbage. That's why I bought a 500' spool, ran a CATV installation, an 800MHz antenna installation and have plenty left over for future use. Don't let the name Wal Mart fool you, it's major stuff when you dissect coax with a pen knife before buying it.

One thing to note for the unfamiliar, quad shield requires a somewhat larger than normal F connector and you need the proper crimping die to put it on unless you don't mind crushing it.

Fred, do what you want just bear in mind RG-8X is pretty close to useless above 30MHz or so but just fine for HF where loss isn't such a problem. FYI every 3dB represents cutting the signal in half and you can easily do that in the average run. If you can't see it you can't read the chart or the one on the optometrist's wall either. (;->)

 

[key2_altfire]

Belden 9258 RG-8X 50 feet - 460MHz loss=4.201

Is this the same RG-6 that they sell at Walmart for $19 for 50 feet?

Over 4 dB at 460 MHz is major loss dude!

You can get LMR-240 from hamcity.com for about the same price as the Wal-Mart cable. (They get $0.54 per foot of LMR-240.) LMR-240 is still lossy but will save you about 2 dB over RG-6 if you keep the frequency under 400 MHz. Over 400 MHz the RG-6's attenuation goes up asymptotically.

 

[zguy1243]

I see a thread like this everyday. Why do you put up a outdoor antenna? To get better reception right? Well don't try everything in the world to avoid spending a extra few dollars on the coax. I would spend more money on the coax than the antenna in most cases. Don't use Rg58,RG8,RG59. And most Rg6's on a antenna setup that will operate at all above 200Mhz are no good either. Its a waste. Some RG6 is ok, make sure its a well known name and dont use it above 400Mhz or over 50 Feet. Live by those rules and your antenna wont suck, I promise. Every Db counts!

 

[rfradioconsult]

Like the director said, can the dialog and cut to the chase. Off brand or oddly marked with "pro" or some other nonsense coax is like a box of chocolates, you never know what you're going to get. That RG-6U quad shield coax from Wal Mart is the best you can get, plain old RG-6 from anywhere is garbage. That's why I bought a 500' spool, ran a CATV installation, an 800MHz antenna installation and have plenty left over for future use. Don't let the name Wal Mart fool you, it's major stuff when you dissect coax with a pen knife before buying it.

One thing to note for the unfamiliar, quad shield requires a somewhat larger than normal F connector and you need the proper crimping die to put it on unless you don't mind crushing it.

Fred, do what you want just bear in mind RG-8X is pretty close to useless above 30MHz or so but just fine for HF where loss isn't such a problem. FYI every 3dB represents cutting the signal in half and you can easily do that in the average run. If you can't see it you can't read the chart or the one on the optometrist's wall either. (;->)

Consumer type receivers normally express their receiver sensitivity in voltage not watts. Half power is 3DB; half voltage is 6DB.

 

[N1GTL]

4 db loss for 50 feet?? What are you using, kite string???