| Author |
Message |
    
Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 238
Registered: 10-2002
| | Posted on Friday, December 09, 2011 - 6:49 pm: | 
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TECH 833, Several month's ago you said you would check to see what the actual power loss would be for this cable. My question is have you had the time yet to check this out? It is suppose to be 0.7 per 100 foot according to Copper. If correct if you put 10 watt's in a length of 100 foot it would be 8.5 watt's out. If that is correct at the end of a length of 500 foot it would be 4.5 watt's out. Of course the more power in the more power lost. If I am incorrect please let me know. |
Barracuda
Intermediate Member
Username: Barracuda
Post Number: 347
Registered: 3-2003
| | Posted on Friday, December 09, 2011 - 7:36 pm: |
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The % power loss would be fixed. The power loss and power remianing would, therefore stay in the same ratio. As far as your assumptions of approx 4.5 watts out of a 500ft run @0.7 db/100ft, yes that's about correct. 5*0.7dB = 3.5dB = power factor of 2.23872. 10w/2.23872 = 4.4668 ~ 4.5
This assumes that the dB loss/100ft of ca-400 is 0.7dB at 27mHz. I think ca-400 is similar to LMR-400 which has about 0.642dB loss /100ft at 27mHz. |
Tech833
Moderator
Username: Tech833
Post Number: 2077
Registered: 8-2002
| | Posted on Tuesday, December 13, 2011 - 12:35 pm: |
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Yes, that's right.
I purchased a 500 foot roll of CA-400 cable from Copper (I pay full price, just like everyone else) and the spool has arrived. However, I have not yet unpacked it as I have had many work related projects that take priority.
The way it is wound on the spool, the entire length needs to be unspooled in order to access both ends. Also, I need to accurately measure the length to make the test accurate.
Your radio 'Mythbuster' since 1998
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392
Intermediate Member
Username: 392
Post Number: 145
Registered: 6-2003
| | Posted on Friday, February 03, 2012 - 10:27 am: |
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833, ay further on this one? I have to make 3 runs at 175 - 200 per antenna. Was thinking of using this coax.
And I do appreciate all of your feedback! |
Tech833
Moderator
Username: Tech833
Post Number: 2117
Registered: 8-2002
| | Posted on Saturday, February 04, 2012 - 9:25 am: |
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All cable still neatly stored on the roll. Will be doing this as weather and work schedule permit.
Your radio 'Mythbuster' since 1998
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Dale
Senior Member
Username: Dale
Post Number: 1822
Registered: 12-2002
| | Posted on Saturday, February 04, 2012 - 10:24 am: |
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392 just one question, why so much coax?
just curious usually 50 feet is enough
for me. but of course my antenna and radio
are only seperated by the window/wall.i try
to to it that way to keep all runs as short as possible.same w/ jumpers short as possible
dale/a.k.a.hotrod
cef426
cvc#64
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Tech833
Moderator
Username: Tech833
Post Number: 2121
Registered: 8-2002
| | Posted on Saturday, February 04, 2012 - 9:41 pm: |
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That's nothing, Dale. I have some runs over 400 feet here.
Anything over 200 feet (on HF), I prefer to use Heliax. Anything over 25 feet on VHF or higher, I prefer Heliax.
Your radio 'Mythbuster' since 1998
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Tech237
Moderator
Username: Tech237
Post Number: 1531
Registered: 4-2004
| | Posted on Sunday, February 05, 2012 - 8:45 am: |
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Like 833 I also use Heliax for long runs. I also can get "ends of rolls" of Cable Company street level hardline cheap ($0 is cheap).
By the way - an end of roll can be 100ft plus - not long enough to run along a street, but long enough for a ham installation.
Now this is 75 ohms, but careful cutting (multiples of a half-wave) and the worst SWR I've had was 1.6:1. Now plugs can be an issue, but a standard PL-259, a short piece of aluminium tubing and soem self-sealing tape and all works well.
Tech237
N7AUS
God made me an athiest, who are you to question his wisdom?
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Tech833
Moderator
Username: Tech833
Post Number: 2122
Registered: 8-2002
| | Posted on Sunday, February 05, 2012 - 5:37 pm: |
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FYI, Hardline will not roll up on a roll. Hardline comes in 10 or 20 foot lengths and bolts together with flanges.
Your radio 'Mythbuster' since 1998
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Tech237
Moderator
Username: Tech237
Post Number: 1532
Registered: 4-2004
| | Posted on Monday, February 06, 2012 - 8:42 am: |
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Well it's tagged on the drum as hardline. Solid copper innner conductor the size of the pin on a PL-259 and a solid tubular aluminium outter - certainly isn't heliax.
Tech237
N7AUS
God made me an athiest, who are you to question his wisdom?
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Tech833
Moderator
Username: Tech833
Post Number: 2123
Registered: 8-2002
| | Posted on Monday, February 06, 2012 - 11:48 am: |
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If it will roll up, then it isn't "hardline". So, perhaps someone with a label maker is confused.
I hear the word "harline" from hams all the time, when they really mean "semi-rigid cable". It's a common misconception that any cable with a solid outer is "hardline". In fact, "hardline" resembles conduit more than coax. It's like having a conduit inside of another conduit. You certainly cannot roll that up.
So, the next time some know-it-all ham is tossing around the word "hardline" you can show him / her how smart you are because you actually know the difference between "hardline" and "semi-rigid coax".
What you have on your spool(s) is semi-rigid coax cable. Absolutely NOT hardline.
Your radio 'Mythbuster' since 1998
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392
Intermediate Member
Username: 392
Post Number: 149
Registered: 6-2003
| | Posted on Monday, February 06, 2012 - 8:44 pm: |
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Dale, the antennas will be at 100 feet, then there is the distance to my shack. I put the tower back a bit to get it out of the way. I may be able so squeek buy with 150 feet. I will have 2 meter, 6 meter and 10/11 meter antennas. Hey I posted some pics in the members photos section. Hopefully we will have 70 feet up this weekend weather permitting!
833 I will give that CA-400 a try. Lon posted a very good post in 2008 on this forum, claims this stuff is super. Price is right so what ya think??
Tim |
Tech833
Moderator
Username: Tech833
Post Number: 2124
Registered: 8-2002
| | Posted on Thursday, February 09, 2012 - 12:14 pm: |
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What do I think? I bought a roll of it myself. It looks pretty good to me. Comparable to Times brand LMR-400 from what I can tell.
Your radio 'Mythbuster' since 1998
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392
Intermediate Member
Username: 392
Post Number: 155
Registered: 6-2003
| | Posted on Monday, February 13, 2012 - 8:03 pm: |
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Done! As always 833, thank you. As soon as we are at mak height, I will buy. |
