LMR 400 vs standard RG8X

[Rick330man]

I had bought 50 ft of LMR-400UF to put on an outside antenna but, my landlord won't allow one.
So, I cut off a little over 15 ft of it and ran it in my mobile to the big home made steel mount and 5/8 hole for the breedlove mount I use for my 102" SS Whip and 7 ft Skip Shooter.
I know it's overkill but, it works fantastic.
Might as well use it instead of it just sitting there.

Do your patriotic duty: put up a fiberglass flag pole! The fact that it might just coincidentally have a 102" whip on the inside shouldn't prevent you from being a law abiding, flag hoisting, 1st amendement-loving, radio operating citizen..

 

[TIN_CAN]

If you want cheap LMR-400 go to amazon and get some KMR-400 picked up 100 feet for $89 Canadian. See how it holds up.

Amazon product ASIN B085G6GH95

 

[Eldorado828]

If you want cheap LMR-400 go to amazon and get some KMR-400 picked up 100 feet for $89 Canadian. See how it holds up.

Amazon product ASIN B085G6GH95

Center conductor is copper clad..... That's odd.

 

[Eldorado828]

Just finding this out due to a forum member bringing it to my attention.



I was not aware the times microwave lmr is also copper clad center conductor. I learnt something today.

I use poor mans lmr rg213 and has served me very well. Never have had the need for lmr so have never researched it.

 

[Groundhog KSS-2012]

Just finding this out due to a forum member bringing it to my attention.

View attachment 61102

I was not aware the times microwave lmr is also copper clad center conductor. I learnt something today.

I use poor mans lmr rg213 and has served me very well. Never have had the need for lmr so have never researched it.

I'm not a wealthy Man myself. But, I do scrape and dig for good coax when I need it. Although from what I've read, if not for the slight difference in loss, RG 213 is almost as good as LMR-400.
LMR-400 may be better in a 100 ft run because of loss, but I've only read that here. I've no experience comparing the two. None whatsoever.
So, I'm sure RG-213 is a great choice.

 

[Rwb]

i despise lmr 400. stiff lossy but to each his own. aluminum isnt a grest signal carrier. copper is much better. my 2 bits worth

 

[Smokinone]

I've been using 9913F, was using some Columbia RG8 before that. Can't say I really noticed any difference other than the Columbia was a little stiffer.

 

[Captain Kilowatt]

i despise lmr 400. stiff lossy but to each his own. aluminum isnt a grest signal carrier. copper is much better. my 2 bits worth

Absolutely nothing wrong with copper clad aluminum for RF conductors. The aluminum is insignificant due to the skin effect. LDF4-50 is 1/2 inch heliax with very low loss and it is copper clad aluminum centre. The braid on LMR-400 is copper clad and the shield uses an aluminum foil for 100% shielding and tinned copper shield so it does not interact with the aluminum foil.

 

[Dr_DX]

Amazon product ASIN B003NQ0CU6
.78/foot

 

[TIN_CAN]

Center conductor is copper clad..... That's odd.

View attachment 61097

Thats why it so cheap...if it fails to be useful then I am only out 100 Canadian bones, then I will have to spend a little more and order from jeffaTech.

 

[Alabama Buckeye]

Thats why it so cheap...if it fails to be useful then I am only out 100 Canadian bones, then I will have to spend a little more and order from jeffaTech.

I'm surprised there aren't far more occurrences of copper clad coax; in asmuchas current flows on the outter skin, why not?
Though the corrosion factor exist, if I were looking for short term application, I might be inclined. But, it would have to be mighty cheap!

 

[TIN_CAN]

I'm surprised there aren't far more occurrences of copper clad coax; in asmuchas current flows on the outter skin, why not?
Though the corrosion factor exist, if I were looking for short term application, I might be inclined. But, it would have to be mighty cheap!

That why I bought it as is was only $100 Canadian ...Hence the mighty cheap.

 

[Alabama Buckeye]

Although from what I've read, if not for the slight difference in loss, RG 213 is almost as good as LMR-400.
LMR-400 may be better in a 100 ft run because of loss, but I've only read that here.

dB loss / 100'

You can certainly do worse than RG-213; namely RG-8X or 58 (350-400W). Though with Velocity Factor there is little or no difference. The lack of a foil 2ndary shield? Probably attributes to the 0.36dB loss increase?

I've a couple 50' lengths of RG-213 that I mull over and around about using. The weight of it is the #1 hold off, on it; and, Flexibility #2.
A big + is, I have it on hand, #2, and power handling. capability is #1 (1800W). Can I live with any loss of antenna gain; whether that be a 5/8 monopole or 3 element yagi. These are my considerations.

 

[Naysayer]

I need a 75' length of cable w/ PL259's. 2/3 of it will be an outside vertical run. HF only. I've been using cheap RG8 from decades ago that was stored.
What is JEFA?
I was set to shop for LMR400 when I found "LMR400/213 type" ads for a BR400 cable. Terminology is getting tricky.

 

[Dr_DX]

So where is everyone getting their coax from these days?

For over 25 years without a single issue it's the Original Wireman. https://thewireman.com/ SIX-SHOOTER

www.worldwidedx.com

AFAIK, Times Microwave made the original LMR series cables, including LMR-400.

All of the other manufacturers listed in the above link make a knockoff version of LMR-400. Different names but virtually identical specs to LMR-400. Buy what is cheapest for you.

Jefa = Jefa Tech, a coax (edit) reseller.

MIL Spec RG213 uses a solid PE dielectric with a V.F. of 66%. I have seen some "RG213" that is being made with a foamed PE dielectric with a V.F. of 80%

LMR-400 and it's knockoffs are the same size and use the same connectors as RG213 and they have a V.F. of 84~85%

NOTE: I am sure this will get some flames going but for any coax that uses a "foam" dielectric, I recommend using a clamping style connector. IMHO, You can probably solder the center conductor if you are quick and have good technique (I use some heat sinks on the center pin), but no one is good/fast enough to heat up the body to solder the shield to without melting the foam dielectric to some degree. And when that happens, you no longer have 50 ohms impedance at that point.

I have included a JefaTech Low Loss 400 spec sheet from 2005 and a Times Microwave LMR-400 spec sheet from 2007 for comparison.

Good Luck!

P.S. I have used Jefa Tech LMR-400 since 2005 in various installations including my mobile and base and never had a problem with it.