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Member
Posts: 181
Registered: ‎09-29-2009
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Using Coax cable to connect Bullets to antenna's

Anticipating winter to hit soon and given the less than 100% reliability being experienced, I'm considering simply running coax from the antenna to the bullets/rockets to permit accessibility at the ground rather than 80 to 120 ft up in the winter winds.

Any "heads-up", advice, warnings or technical insights will be very welcome here.

Primarily, 1) recommended wire type etc. 2) max reliable wire run lengths 3) anything else you know that I don't know or can't look up easily (experience).

Thanks in advance.
Mike
Senior Member
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Re: Using Coax cable to connect Bullets to antenna's

Im not very experiened with the different types of cables used, I believe my ISP used LMR 400 for a certain tower.

www.ocarc.ca/coax.htm
this is a good site, go to the bottom and you can calculate your signal loss
Regular Member
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Re: Using Coax cable to connect Bullets to antenna's

The simplest calculator is here: www.timesmicrowave.com/cgi-bin/calculate.pl

You won't like the results much... What frequency are we talking about, 2.4 or 5 GHz?

If 2.4 you will need minimum of LMR600 for that distance, if 5.x you need something like Andrews LDF4.5-50 which is expensive. LMR400 is likely too high a loss for antenna-to-ground applications.

George
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SuperUser
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Re: Using Coax cable to connect Bullets to antenna's

Times LMR400 is the 'gold standard'
and that's a handy calculator.

The bottom line: 100ft of LMR400
at 5.8Ghz has about 11dB loss. Add
two extra connectors at 0.5dB each.

If you have 12dB of extra gain in your
system, this will work well. Otherwise--
as George pointed out--you'll need
lower-loss cable--and some luck!

LMR600 (bigger and more expensive)
only improves this by 3 to 4dB.

Remember: you'll have this loss on
both ends if you have similar setups
on both ends. How about -24dB!

You may find that putting up two complete
systems will give you redundancy at much
less cost. CAT5 has no rf loss. And if
you've had reliability issues in the past, be
sure you're using proper shielded cabling,
grounding and transient protection. Dave

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Member
Posts: 181
Registered: ‎09-29-2009
Kudos: 7

Re: Using Coax cable to connect Bullets to antenna's

Ruining your best achieveable RF setup, by running lots of expensive cable, because you're afraid the kit doesn't work is a bit odd isn't it ?

Maybe use something else for now.


Not that odd when one considers the current state of reliability on the M5 product lines and given the feedback coming in I believe the "fear" as you put it is substantiated.

However, perhaps simply being redundant and install another setup on both ends just in case perhaps might be less expensive than cables etc.. I'll need to check into it that and wait out the maturity of the product.

This is for Point to Point at 5.8ghz.