coax question

[axplayer]

So I'm trying to determine if RG58U coax that is used for video purposes is the same type of cable that is used with radio equipment. Has anyone heard of RG58U being used for video? Is the cable different from those used for CB? The only difference I can think of is maybe the shield isn't copper as it normally would be, but I could be wrong. Anyone that has experience with this, please help!


Thanks!!

 

[midnight special]

yea i have seen it used for video cables too, but usually it is the low grade cheap stuff , it really depends on the maker and materials put in it,, the sheilding might be very lossy and the center core might be stranded but small in comparison with quality rg58..... i have seen rg58 from radio shack that when contuity tested showed good but when hooked up to radio and antenna would show flat swrs,,, but then it wasnt outputting, just acting like a dummy load,,,you might look up online the maker and specs to velocity factor and sheild %...

 

[axplayer]

Hmmm.....just when I thought I had things figured out. I did try and search but I couldn't really get any answers.

http://www.ultraproducts.com/applications/SearchTools/item-details.asp?EdpNo=1725552&CatId=1213

It's a 50ft @ $8. but if it doesn't work well on CB than it doesn't matter. Why would they use rg58u for videos when they run on 72-75omhz? I wish they would just keep things simple and stick to rg6 for all video coax instead.

 

[Captain Kilowatt]

Most video is 75 ohms and they use RG59 which is 75 ohms not RG58 which is 50 ohms. Not all video however is 75 ohms and some of it is 50 ohms such as the old ethernet cables. Makes it interesting when you have a patch panel and a bunch of cables as the BNC connectors for 75 ohms have a smaller inner pin than the 50 ohms BNC connectors.

Coax is usually about the cheapest item in a setup so don't even bother looking for a cheap way out. Buy decent quality cable because this IS a case of you get what you pay for.

 

[Singularity35]

I had a close circuit system that specified rg58. I tried both rg58 and rg59. I didn't notice any difference.

 

[axplayer]

I had a close circuit system that specified rg58. I tried both rg58 and rg59. I didn't notice any difference.

My greatest concern about the rg58u for video is the shield. It may not be copper and it may have too much loss. I think reception would be okay but transmitting may be under par when compared to regular RG58u for communications.

BTW, I thought RG59U was special coax only for co-phase. I could be wrong.

I've decided to get some good old regular rg59u from a reliable seller instead of trying find it on craigslist.

 

[Captain Kilowatt]

My greatest concern about the rg58u for video is the shield. It may not be copper and it may have too much loss. I think reception would be okay but transmitting may be under par when compared to regular RG58u for communications.

It does not matter if the shield is copper or aluminum as far as shielding is concerned. In all likelihood it is copper or if silver coloured it is tinned copper braid. Equally effective. My concern about the shield would be the coverage and not the material itself.

BTW, I thought RG59U was special coax only for co-phase. I could be wrong.

Nothing special about it. It is simply small diameter 75 ohm coax. Its' not MEANT for phasing lines (no such thing as co-phasing but that has been beat to death already elsewhere) but rather it just happens to be of the right impedance to use when connecting two 50 ohm antennas together. 36 ohm coax would do the same thing if it was available. There are other types of 75 ohm coax as well such as RG-11 or RG-6.

I've decided to get some good old regular rg59u from a reliable seller instead of trying find it on craigslist.

Good idea. Buy good brand name cable from a reputable source. Just remember that the cable should always be 50 ohms (which RG59 is NOT) unless it is to be used for impedance transformation such is the case when phasing two antennas.

 

[222DBFL]

Look at Belden, Andrew, times microwave, 50 ohm coax is what you want. RG58 is okay for short runs and low power. When I say low I mean a couple hundred watts max. And normally you don't want a run over 25-30ft. Get some mini 8 or lmr240 from one of the companies I listed above. JMHO. Again 50 ohm coax is what is needed for cb radio use.

 

[midnight special]

i use belden when i have it,, amperol i seen as the best,,, i use amperol rg213 9 feet long on my pickup mount to the amp then 6 feet of belden rg8x to the radio,, works splendid can talk out about 25 miles no problem and if conditions good talk skip easy,, this is into a 102 inch steel whip with a military 6 inch spring on a hustler c32 modified ball mount, amp is just 50 watts and just an old cobra 29 that i bought out of yard sale for 2 dollars and re worked,, ugly radio but it works and not much loss if stolen,,

 

[M0GVZ]

RG58 is okay for short runs and low power. When I say low I mean a couple hundred watts max. And normally you don't want a run over 25-30ft. Get some mini 8 or lmr240 from one of the companies I listed above. JMHO. Again 50 ohm coax is what is needed for cb radio use.

RG58 is good for over 400W if the SWR is low. The losses at 100MHz over 100ft is only 0.7dB over RG213. At 27MHz the difference will be far less.

 

[rabbiporkchop]

So I'm trying to determine if RG58U coax that is used for video purposes is the same type of cable that is used with radio equipment. Has anyone heard of RG58U being used for video? Is the cable different from those used for CB? The only difference I can think of is maybe the shield isn't copper as it normally would be, but I could be wrong. Anyone that has experience with this, please help!


Thanks!!

times microwave LMR 240 is much less lossy than rg58