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Coax help

S

Stump31

Member
Mar 13, 2008
12
0
11
NJ & Florida
I am setting up a new antenna and will have to make a 300'+ coax run. What is the best coax to use. Most of the run will be underground. Has anybody used this H00-02006 Altelicon CA-400 Cable from Copper. Is it better than Beldin 213?. I am open to all suggestions. I will be running 1500+ watts through the system.

Thanks

Stump31(y)
 

It's too bad that you must have such a long coax run for your system. The loss over such a length - even with good cable - would be unacceptable in my book.
Is it necessary to use such a long piece?

Here's a coax calculator for you to figure out your losses due to cable inefficiency:
Coax Calculator

Remember this fact: just 1db/100 ft of loss from your coax reduces the output power of your radio by 20%. For 300 ft, multiply it by 3. That is - if your system is going to throw 1500 watts output; then only 600 watts are getting to the antenna.
Makes you think twice about having a long coax run - eh?
It should.

The crappier the cable - the losses go from bad to worse.
The longer run you need with crappy cable means you are wasting power and efficiency.
SO - use only the length that is necessary and buy the best coax you can!
If you lose 3db/100 ft with crap cable; you have lost HALF of your output.
Check it out...Do the math...
 
Last edited:
Complaining about realizing "only" 1,200 watts out of 1,500 in? Boy are you hard to please.

1,200 watts is still 1,200 watts.

80% of a 22oz. porterhouse steak is still alot of great steak.

Just search and buy the cheapest 100% shielded RG8 type you can find.
 
Place the buried portion in plastic pipe and be sure to glue/seal all the unground connections and seal the ends so water & stuff can't creep in. Seal open ends with 100% silicone caulking. You only want to do this once and make things as permanent as possible.

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It says that Altelicon CA-400 Cable has 2.1dB loss for 300 foot at 30MHz.
That is about 60% of the power making it thru.
So 1500 watts would become around 950 watts.

But you must put it in perspective: that's about 1/3rd an S-unit.
 
Well...

For all those who say i waste my money on hardline
This is a perfect example to use it

Especially given he will use 300 ft (i use 165 on my HF)
Will easily handle his 1500 watts (with some loss in power of course)
Can easily be buried

I use Andrews Heliax LDF5-50A (but use 165 ft)
But for his 300 ft run..i would use my LDF7-50A
(this coax calculator does not show my LDF7-50a but is a bit better then the LDF6-50A)

However i am the first to say it will cost you a bit
But knowing your good for at least 10 yrs

Well you can chose what works best for you
 
Thanks for the info

Thanks for all the replies. You have given me a lot of food for thought. I did not think about so much loss in power with the long run. I am going to see if I can make it shorter but If I can't I will look into the better coax like the Heliax. One question about Heliax will a standard pl-259 plug fit on it or will I have to modify things? Also what is the coax ground kit for? Do I need that if the antenna is grounded already?

Thanks again for all the great replies,

Stump31(y)
 
If you decide on heliax be prepared for sticker shock. That stuff sells for dollars per foot not feet per dollar. The connectors are around 20-30 dollars each for the LDF4-50, which is ½ cable, unless you are lucky and pick some up elsewhere cheaper.they can be a bugger to install too if you have never done it before.The grounding kit is what bonds the cable shield to your ground system. In your case instead of using heliax I would reconsider the burying of the cable and use open wire line with a balun on each end. It will have less lose than all but the very best cable and a whole lot cheaper too.
 
Myself i have two 150 ft runs of LDF5-50A feedlines
as well as 165 ft run of LDF7-50a

Agreed....They are NOT Cheap
But they are about the best you can get
 

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