| Author |
Message |
    
Wrk3
Junior Member
Username: Wrk3
Post Number: 44
Registered: 4-2004
| | Posted on Thursday, February 10, 2005 - 3:21 pm: | 
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i'm about 2 put another antenna up there. i'm currently using rg-213, how much.....would i benefit from using lmr-400, since the efficientcy is about 7%. or lmr-600 which is about 11%. forgive me 4 asking dumb questions 4 i know lmr is supposidly a better cable.
would the increase make my station perform better?///in what way/s? |
Hatchet
Junior Member
Username: Hatchet
Post Number: 14
Registered: 7-2004
| | Posted on Thursday, February 10, 2005 - 5:31 pm: |
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Honestly you probably wont notice any differance at all unless it is a really long run. Anything under 100' and Id leave it alone
Buck |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 253
Registered: 9-2004
| | Posted on Thursday, March 03, 2005 - 11:03 pm: |
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i agree with hatchet somewhat, but i believe there are other advantages to using this coax. (lmr400)
the db loss is not much different at 100' for 213 and lmr400. i think its like .3 db.
the lmr400 has a greater velocity factor, meaning that electricity will move faster through it than the 213.
the shielding is also superior. FAR superior in my humble opinion. this means less or no TVI.
and the shielding will pickup less noise, resulting in a more sensitive receiver.
i myself am stepping up to lmr400 from 213u and i'll post my findings. insignificant as they may be.
matt
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Cornbrown
Junior Member
Username: Cornbrown
Post Number: 43
Registered: 7-2005
| | Posted on Sunday, October 09, 2005 - 8:08 am: |
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I am also stepping up from RG213 to LMR400UF. I like the extra sheilding which will help with TVI I think, and help give a quieter receive. |
Sinker
Intermediate Member
Username: Sinker
Post Number: 145
Registered: 8-2005
| | Posted on Sunday, October 09, 2005 - 9:44 am: |
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I have gone with LMR-400. I too was told that anything less than a 100' run it really was not needed. My run is indeed in excess of 100' and I also liked the idea of better shielding so as not to bother my NON-RADIO FRIENDLY neighbors.
It is thick and not very flexible and I have found that it is not very good for short jumpers. As a result I have only used the LMR-400 after the AMP everything before is RG8X double shield.
Not sure I have noticed any better performance with the LMR-400 but I also do not know how to test for loss etc. not to mention those here who know MUCH more than I do recommended it so I went with their suggestions.
Hopefully in a week or two I can post full pics of the new station and LMR-400.
Tim
CEF-634 |
Bruce
Senior Member
Username: Bruce
Post Number: 3147
Registered: 9-2003
| | Posted on Monday, October 10, 2005 - 6:43 am: |
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At CB coax is not a problem. Any good coax and both are good will work just fine. |
Tech833
Moderator
Username: Tech833
Post Number: 1063
Registered: 8-2002
| | Posted on Monday, October 10, 2005 - 11:55 am: |
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Bruce,
I am sorry, you are mistaken.
First of all, on CB and even on lowband, double shielding (100% shielding) makes a very noticeable difference in your receiver noise floor when you run that coax past noise sources (like electrical or computers, or whatever). Also, the 100% shielding can reduce TVI in some cases.
The Amateur Radio Handbook is NOT the authority. In fact, every year it comes out, I enjoy flipping through it and pointing out the inaccuracies. I am never invited to proof read them before publication, I am usually told to mind my own business. Truth hurts when you have a ham ego. |
Dx431
Senior Member
Username: Dx431
Post Number: 1110
Registered: 2-2002
| | Posted on Monday, October 10, 2005 - 12:09 pm: |
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Unless you plan to run excessive power, you and the person on the other end will never notice the differance.
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1646
Registered: 7-2004
| | Posted on Monday, October 10, 2005 - 12:46 pm: |
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I AGREE WITH 833 150%!!!
i was taught to use 'BETTER GRADE' coax in the 70's when my STOCK 4 WATT SEARS radio caused TVI in the pre-cable TV days. it helped a great deal in reducing interference to BOTH my receive & others' appliances. and, YES dx431 is 100% correct that the person on the other end, in MOST cases will NOT notice the difference. BUT that is NOT NECCESSARILY what you are looking to improve with better coax, you are looking to reduce the chance of incoming & outgoing interference. if you live without neighbors closely situated to you & do not have to deal with noises generated by todays' toys, or worry about RFI being generated by your station to those nearby, & are willing to deal with whatever the atmosphere throws at you, go ahead & use a lesser grade coax. just remember, that the 'better' coax is helping to keep junk OUT of your radio as well as insuring your signal is being radiated ONLY by the antenna & NOT by the coax as well.
i've been professing the use of BEST AVAILABLE COAX on this forum since the day i got here, & will stand by it til i'm gone! most of us have HUNDREDS if NOT THOUSANDS of dollars invested in our stations-whether they be CB ONLY or amateur as well-why would you NOT spend an extra $20 on the BEST COAX YOU CAN GET???? |
Bruce
Senior Member
Username: Bruce
Post Number: 3148
Registered: 9-2003
| | Posted on Monday, October 10, 2005 - 2:47 pm: |
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833 ....
I run on 2 meters a good grade of coax lmr-400 grade. Measured loss even at 100 foot is fairly small ....
MABY for some a high grade of coax will show a lower noise floor but at my location with the exception of RADIOSHACK coax all I have used again good stuff work just fine..... no cheap off brands ...... no one is saying THAT.
One thing i have found that helps with TVI is a coil of coax at the antenna base OR a few beads just below the coax connector.
My pick LRM-400 class even at 440 mhz it is more that enough. |
