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I was going to order 50' of Belden 8262 but it looks like its being discontinued according to AES.
Which coax do you recommend?
I'm going to be installing it in about a 15'-20' length. Its going to go through the wall, and directly onto the roof where the Antenna will be mounted.
What frequencies do you plan on using it for?Quote:
Originally Posted by K9CCH
Right now I'm strictly 2/70cm, no HF yet. And it will be a while before I can even begin to think about an HF rig.
9913 and LMR-400 are good choices. Although you're not really using a long run of coax, might as well use quality cable.
Performance characteristics of widely-available coax
Ah! Spank you very much.
8262 looks to have pretty poor characteristics for VHF/UHF. I use LMR-400 for anything above 50MHz myself although for that short run you could probably get by with something cheaper. Consider using N connectors on your outdoor connections as well. They're waterproof and are a better impedance match than PL-259s.
If I'm not mistaken, I'm using the Belden 8262 for VHF/UHF/HF runs at the moment. I got a 500ft spool for a song ($10), so it was a no-brainer to use.
If I were paying full price, I wouldn't use it (It's mainly used for cable TV installations if I recall the research I did), I would use something that does VHF/UHF better. HF, it's almost a non-existent loss, but those higher bands, you're looking at a 0.5db/10 ft loss (Again, off the cuff).
Even for a shorter run, I'd pick something a little better, if you're paying full price. If you're getting it like I did, go ahead and use it until you get a better deal on something better.
LMR-400 at the minimum.Quote:
Originally Posted by K9CCH
Look at the cost this way... better to spend a little more NOW to get quality coax (and 8262 is not known to be a good V/UHF coax), than to have to rip out the coax used, throw it away, and then replace it with the good stuff. Consider the "cost" of your time & effort as well, especially if you may have to "undo" and then "redo" the job.
One suggestion: As long as you're drilling a hole for coax, drill an extra one or two. Saves time in the long run, do it while you have the tools handy. Now, if you can get one at a hamfest, you could mount a "long barrel" (12 inch to 18 inch double-female SO-239) for future use, or even just put a short run of coax there (I would put a baggie and a lot of tape around the outside connector to protect it from the weather)
You may not have HF today, but you might down the road. Or have a need for another V/UHF band. etc.
Just a suggestion.
I don't care for stinkin' coax.
http://www.rogerwendell.com/images/m...04-20-2008.jpg
And yes, it works very well on VHF/UHF, you have to mind some issues. Low loss, arguably better than hardline. Biggest issue is it's a bitch to use on rotatable antennas. But a low loss balun with short runs of the expensive coax is a good solution there, at least through the VHF regions. Matching UHF is trickier, but do-able.
Another thing to consider is quad shield RG-6 75 ohm cable. It's very cheap, and low loss. All you have to do is make a short matching section of 50 ohm coax, using "the good stuff". This is done very easily with an antenna analyzer. Many of the RG-6 quad shield cables can handle a surprising amount of power, check the specs.
I have a bunch of surplus RG-6 quad shield that I got for free. Hams like free. :yes:.
Quote:
Originally Posted by W3WN
Im not drilling anything. The satellite dish is directly above the room that the radio will be going in. And there is already coax running from the dish to the room. But it's Cable TV coax installed for our modem. We've since switched companies and now that we have Uverse those lines aren't used anymore. I'm just going to pull it out and replace it.
And now that I'm looking at it, there's enough coax left over that I could probably just rip it off the house and connect it to the j pole. On the inside is a standard SMA connector on the wall. Could I use that coax and get a jumper to go from the radio to the wall? Comcast installed all this a year ago, and we kept Comcast for two months before canceling their service.
i know it's not optimal, but can I use what's already there?
"i know it's not optimal..."
What's not optimal about it? There is no industry standard, this is AMATEUR radio meaning if it works, use it, don't ask why or how, who cares?
"...but can I use what's already there?"
Bingo, we'll make a ham out of you yet.
OK, let's look at this logically, cheap is good and free is best, right? What you need is already there, free! Sat dish mount used for J-pole, coax used for J-pole, free so far and a couple of connector adapters, cheap. OK, so it's 75 ohms? That means only 1.5:1 SWR feeding a 50 ohm load but a J-pole can match to 75 ohms, the rig may not be 50 ohms exact so expect a fairly good match. Signal loss? The dish's block converter output is in the 800-900MHz region so they use a reasonably low loss coax to feed the receiver on the down side so frankly I wouldn't replace good coax that's already right where you want it.
Oh and BTW toss all that scribble scrabble above out and KISS, keep it simple stupid.
Sweet! I didn't even think about the existing coax until I walked outside to look at it today. I'm thinking that tomorrow may be the day I try a new antenna!!
I agree with the above. I would just check to see what kind of cable is there already, and see what max power on it is.Quote:
Originally Posted by kb2vxa
I agree with this. If it works, use it.Quote:
Originally Posted by KC2UGV
Well I'll be go to hell. FINALLY something we can all agree on. This has got to be an Island 1st.
Sounds like you have just about everything you need. Now, GET TO IT.
Quote:
Originally Posted by K9CCH
They have really good deals on LMR 600 around. That is a nice coax. LMR 400 would be second choice, but if you are vhf the 600 is better and a good price now.
The coax that is here is
AMPHENOL BBS TFC-T10 CHINA 4001538 6 SERIES (ETL) us CATV 18AWG
as per the writing on the cable.
For what you are doing hardline is best. I am a former BE. Hardline works best for VHF/UHF applications. The stuff is not cheap, and the connectors are from Hell. I was able to buy a spool of HD line for about $1.00/ft back in 1995. The losses are almost NONE!!!!. You will hear weak signals that no one else can, even with a zero gain 360 degree vertical aerial.
Oh, almost forgot one of the MOST important facts about CATV coax, aluminium shield so you can't solder to it. That's why installers use crimp connectors, usually an F and like RG6 quad shield and relayed lines ordinary F connectors don't fit. Still it's a cheap and dirty way to go, connectors, adapters and don't forget the stripper and crimp tool don't cost as much as"standard" cable and connectors for VHF/UHF work. Remember CATV cable has low loss up there because all signals are above 50MHz and up into the low GHz range. Unless you're running a kilowatt for EME you may as well clean off the couse while you're at it.
Yeah, hard line is best, etc., etc., which is why only well funded clubs and hams use it. If you own a TV station you can afford hard line.
I ended up buying 30' of LMR400 at the supply store today.
When we used 4 inch hard line at the radio station, I found that plumbing skills were very useful.Quote:
Originally Posted by kb2vxa
Just don't confuse hard line with waste line!
Actually, they can both be full of shit.Quote:
Originally Posted by kb2vxa
What do you do with 6 inch hardline ??
Quote:
Originally Posted by Bubba
Thats what she said...
Good job. Would have been my choice too. Nice bang for the buck factor.Quote:
Originally Posted by K9CCH
Yes, you made a good choice. For a 30' run on 2 meters, I'm not that picky, but LMR400 is a good thing to use.