| Author |
Message |
    
Buck
| | Posted on Sunday, November 30, 2003 - 6:45 pm: | 
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I was just curious if coax gets old and weak after time??? The coax Im currently using is...well...between 20 and 30 yrs old. My swr couldnt get much better(1.2:1-1.5:1) I was just curious if I would notice any differance if I changed it? The old is RG-8 and I do have some 213 here that I bought but I figured if it aint broke dont fix it?!?! Any suggestions?
Thanks
Buck |
Karatebutcher
| | Posted on Sunday, November 30, 2003 - 7:32 pm: |
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Well I had my coax for 25 years and someone told me to get new coax, I will not mention Alsworlds name, but yes its gets old, and you are close to the time to replace, run some checks, Alsworld is a really great help spending your MONEY, he also knows a great deal about coax replacement, in 900 words Ha ha |
Alsworld
| | Posted on Sunday, November 30, 2003 - 7:40 pm: |
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Coax does get old and wears out, but much of it is determined by exposure to the outdoors (i.e. sunlight, and moisture).
Easiest way to check it out is put a power meter on the radio end of your radio and measure outgoing watts during a deadkey. Then, use the same power meter and jumper and put it right in front of your antenna and deadkey again (the other end of the coax opposite the radio). You will need the jumper because you do need the antenna inline, unless you have a dummy load which would be better.
If you deadkey 4 watts out at the radio, and only 1 watt is reaching the antenna, change that coax! That may be extreme, but it does happen with older or weather beaten coax.
I hope I made sense.
Alsworld |
Stickshift
| | Posted on Sunday, November 30, 2003 - 7:42 pm: |
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That's my motto too Buck! The old coax should be just fine. I've got some RG-8 here that is 30 years old also. Heck, come to think of it, that's older than I am! The coax still looks good. Myself on the other hand, that's a different story. I could probably use a hair cut and a shave. The weather here is getting colder and I need to stay warm. I hope Santa brings me a new Gortex coat for Christmas! 
stickshift |
Hornet168ky
| | Posted on Sunday, November 30, 2003 - 8:01 pm: |
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Well, Buck I by no means am a technician but I can speak from my point of view. I would have to say it would depend on how much power you have run thru the coax, and how much weather, rain, cold, hot, etc. I know here in KY. the weather can be brutle sometimes as far as cold and hot and rain is concerned, and alot of the boys around here run several watts thru there coax so they do change there coax i would say at least every 5 years even if they have a good swr.
Me with mine in the truck I change mine every 6 months whether I see a difference in the swr or not. Just because I run the small coax and I know it is rated for alot more watts than I have but still I do this and have done it for several years.
But if you have a good SWR and if you trust what you got then I would say leave it alone.
Hornet168ky
CEF# 219 |
Bruce
| | Posted on Sunday, November 30, 2003 - 8:44 pm: |
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Buck it DOES go bad and alot faster than 30 years.
The best way to test coax is put a watt meter at the end with a 50 ohm dummy load and figure the loss in db if say its supose to be 3 db and you get 4 i would not worry but some old coaxes on like the 440 mhz band will show 9 even 12 db for that 3 db length i dont know if it will show a change in VSWR but i would be willing to bet if you put a 50 ohm load on the end and you read a high VSWR its time to toss that coax and help the copper employee chirstmas fund with a nice coax purchuse. |
Bigbob
| | Posted on Sunday, November 30, 2003 - 8:56 pm: |
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My dad-in-law had a problem,not getting out like he wanted to,he bought some coax used rg8au 95% shield,foam dielectric 30yrs old looked good all coiled up,100 feet long.I brought my swr/power meter over with dummy load,connected swr meter with dummy load in place of antenna,swr was 1.1:1 output was less than 1/2 watt,upon close inspection 25 or 30 feet had very small cracks in it don't know what caused them,but he had more than enough coax so we snipped off the cracked section,viola,same test,1.2:1 swr 3.9 watts out both tests had an input of 4 watts,oh by the way the swr measurements were at the txer the power measurements were at antenna end.We cut open the bad section and the braid was all green and corroded and the foam was a yellowish green and shrunken and cracked.Just some annecdotal experience with old coax.Bigbob |
Taz
| | Posted on Sunday, November 30, 2003 - 10:27 pm: |
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Well I would at least replace the connectors if they are origional. But coax does go bad after time just like anything else. |
Buck
| | Posted on Monday, December 01, 2003 - 7:10 am: |
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Well I think I will climb up on the roof and check it out with a power meter...I will post my findings for you
Thanks everyone
Buck |
mikefromms
| | Posted on Monday, December 01, 2003 - 1:57 pm: |
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If it's not a big job to replace it I'd replace it with the best money can buy. On the other hand, if the antenna is way up yonder and a big hassle to get down AND you are getting good reports and good swr and have no evident problems, I'd say leave well enough alone for another few years.
mikefromms |
Alsworld
| | Posted on Monday, December 01, 2003 - 8:38 pm: |
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Oh Karatebutcher, I do so resemble that remark LOL! That was funny and sadly so true. I have been told I can speak for an hour just to give a yes or no answer. But I sure am good at spending other peoples money he he he.
Alsworld |
Karatebutcher
| | Posted on Monday, December 01, 2003 - 10:24 pm: |
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Hey I enjoy your long posts they have helped me many times, and your longer E Mails
Thanks Friend |
Alsworld
| | Posted on Monday, December 01, 2003 - 11:39 pm: |
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I love a sense of humor, and have one also! Your post was both funny and true. Man I laughed so hard my better half thought I was nuts!!! I just kept laughing....., shoot, I still am! I got a good kick out of it.
Good stuff Karatebutcher!  Don't ever change.
Alsworld |
frasiercrane
| | Posted on Thursday, December 04, 2003 - 3:04 pm: |
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"My swr couldnt get much better(1.2:1-1.5:1) "
one thing about old coax, when it goes bad you won't nescesarily get high reflected, it can develop a lot of loss, and reflected power will just be dissipated in it, leaving almost none to reflect back to your meter. |
Gezus306
| | Posted on Thursday, December 04, 2003 - 6:37 pm: |
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I run my swr's as low as they can go !
My typical setting is : when you dead key
the freq you run most . . . and the needle doesn't even think about moving.
( my mobile right now . . dead key @ 25 watts
and the needle only moves a fraction off
zero ) pickup truck with a 108" steel whip. |
Buck
| | Posted on Saturday, December 06, 2003 - 5:13 pm: |
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Well I got on the roof with a cheap power meter and I get the same power out at the antenna as I get at the radio.....BUT my swr meter would not calibrate at the antenna end. It works fine at the radio end but not at the antenna end. Whats up??
Buck |
Alsworld
| | Posted on Saturday, December 06, 2003 - 7:22 pm: |
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Buck,
I would not worry about it. The power is the factor you were checking and it's good to go. Once the meter is in it's normal position, SWR's are fine. I would hook everything back up and keep using that coax for a while longer. Now you know, and can relax a little.
Alsworld |
Tech833
| | Posted on Saturday, December 06, 2003 - 7:44 pm: |
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Coax does NOT wear out. Coax can, however, be damaged.
I have undamaged coax in use that has been in constant use for over 60 years with 5KW going through it 24/7. As long as the cable is not damaged, allowing moisture inside, it will outlast you. |
Buck
| | Posted on Sunday, December 07, 2003 - 7:15 am: |
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Thanks guys....That was the answer I was looking for. Im thinking about getting a beam so I can use thus RG-213....I sure hate to see it just laying around
Buck
PS When is this new antenna you are working on going to come out??? |
Karatebutcher
| | Posted on Sunday, December 07, 2003 - 9:34 am: |
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WHERE IS ALSWORLD, AGAIN HE GOT ME I AM GOING TO COAX HIM UP |
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