| Author |
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Star Duster
| | Posted on Thursday, January 31, 2002 - 7:23 pm: | 
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Hello - I am using RG-213 for my main coax to help with TVI/RFI and because it is a great coax. Is it OK to use RG-8X for jumpers on my amp and meter? Or should I get more RG-213 and make jumpers with that.
Thanks - SD |
Radiodude
| | Posted on Thursday, January 31, 2002 - 10:27 pm: |
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Go with the 213 |
Colt
| | Posted on Friday, February 01, 2002 - 4:53 pm: |
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I'd like to know, if I want to do all I can (within reason) to keep from coming in on my neighbors' telephones, TVs etc. and I'm only talking on my mobile in my driveway right now, would a coax change make much difference? If/when I set up a base, what steps can I take then, such as filters, coax etc. I used to know all these things years ago, but it's been awhile. |
Warlock
| | Posted on Friday, February 01, 2002 - 8:38 pm: |
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RG 213 is no more shielded than RG8, it simply holds more power.
Doulble shield coax such as Times LMR240 or 400, CQ low loss are the best types of coax to run and are not much more than 213 in cost.
In a mobile it's nearly impossible not to bleed on in house items. |
Colt
| | Posted on Friday, February 01, 2002 - 11:29 pm: |
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Warlock, is that because of the low angle of transmission? I've sort of had that in the back of my mind. Not much can be done about that. |
Warlock
| | Posted on Saturday, February 02, 2002 - 9:06 am: |
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The low angle, no earth ground, your vehicle is your ground plane, so the signa launches right into houses etc.... |
Skoal Bandit
| | Posted on Wednesday, February 13, 2002 - 7:04 pm: |
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The best line we use around eastern Kentucky is stuff called Hardline. It is wire that is used for cable TV line. You have to put RG-8 on each end of it to get the ohms down . Suggested to use 18 ft on each end of the hardline. usually runs 10 cents per foot |
Taz
| | Posted on Wednesday, February 13, 2002 - 11:01 pm: |
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No that is incorrect. Hardline is a coax like 213 u but extremely sheilded and can handle major amounts of power and is only bendable by a pipe bender. |
Triplecguy
| | Posted on Thursday, February 14, 2002 - 12:03 am: |
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I don't want to put my foot in my mouth, but I think that TAZ is correct. The hardline I've seen is a large gauge center conductor with like over a 1/4 inch of dialectric all around it and it is encased in an aluminum shield/outer conductor. You can bend it without a bender, but it will kink and break. But If you could get the ohms to match up, I bet you could run an insane amount of power through that sucker. There was a piece of it in my backyard that was left over from when our local cablevison company retrofitted our whole town with it. Looks like good stuff.
Big Dan |
Marconi
| | Posted on Thursday, February 14, 2002 - 12:41 am: |
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Taz is right. Hardline for 10 cents a foot, give me a break!
Hey SB, that Skoal can be bad for your mental and physical health. Are you sure you are not in the foot hills of Harpers Ferry, West Virginia?
If you can buy Hardline for .10 then you could get rich selling it for a big profit. You give me the specs on what you have and I will buy some and you can double your money. I will also give you a personal appology for doubting you, RIGHT HERE ON COPPERS SITE.
Better yet, send me an email by clicking on my handle at the left of this window and I will give you my personal address and maybe you could send me a foot of what you claim you use. I have heard all this before and I disputed it then as well. |
bruce
| | Posted on Thursday, February 14, 2002 - 12:12 pm: |
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HARDLINE .10 PER FOOT ?????? god we payed at least a buck a foot for small stuff... got a 100 foot roll i can buy ??? |
Znut
| | Posted on Thursday, February 14, 2002 - 6:46 pm: |
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Hey guys, you're on my subject now, great.
There are many forms of hardline, and many manufacturers. Most of that stuff running up the big towers is 50-Ohm hardline, or Andrews type corrugated coax, ranging in size from 1/4 inch up to ??? My specialty is semi-rigid coax. I've bent assemblies with cable diameters from .020" up to .325" to machine blueprints. This stuff is usually made of copper. Anyway, I'm wandering off subject.
RG213 is fine coax for CB use. Low-loss, high power handling at CB frequencies. RG8X or even RG8 would be fine for your jumpers, just use the big stuff from the amp to the antenna.
Somebody mentioned Times' LMR coax. It's great cable, but the loss at 30Mhz is NOT much less than RG213. RG213=1.2db:LMR400=.7db at 100 feet. You have more than .5db loss through your meter or amp. At VHF/UHF frequencies there is a big difference, 2.7db(RG213) vs. 5.1db(LMR400) at 440Mhz. Not worth the price at CB frequencies. However, if you are running BIG WATTS, LMR 900 would handle POWER (KW's @ 27Mhz). That stuff is almost an inch across - the center conductor is about the size of RG8X! And it's hollow to help stop heat buildup.
There is NO need to debate the differences between RG8 and RG213 at CB frequencies, except price and a few watts of power handling due to the extra material on GOOD RG8.
Take Care,
Randy(ZNUT, AKA, Coupling Nut) |
bruce
| | Posted on Thursday, February 14, 2002 - 9:48 pm: |
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Randy as a radio man working in the industry for many years i am well aware of what you said and you are correct at 30 mhz rg-58 is as good as anything for the average cb user running a 50 foot lengh. here where i work to reach our max wing repeater we run 500 foot of LMR-400 at 460 mhz running 100 watts into the cavities of our duplexer. needless to say it is lossy but it covers the jail so no one cares and guss what it was cheaper!!! coax is just a means of moving enegery from the transmiter to the antenna losses are over rated in short runs except for EME or if you are at UHF frequencys.... as you well know at 440 mhz GOOD RG-8 and CHEEP RG-8 an't the same
bruce
radio-doctor@juno.com |
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