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warwick

join:2009-06-05
Hollywood, FL

Andrew 1-5/8" Heliax

Good day...

Recently acquired some used hard line in question, only to find out it's freq. rating tops out at approx. 2700Mhz.

And here I had soo much excitement and anticipation in finally being able to bring back-haul 5.8Ghz radios inside the/a cabinet.
(I literally looked at the cable in disgust)

My question is, who here uses this cable within the 2.4Ghz band. Namely the uppermost channels. I'm a bit wary of operating so close to the manufacturers rated limits or rather what are the implied implications (yes, you read correctly ) in doing so notwithstanding SWR issues.

Regards



Inssomniak
The Glitch
Premium
join:2005-04-06
Cayuga, ON
kudos:2

Re: Andrew 1-5/8" Heliax

I had a company that installed a 900mhz antenna on our tower. There was an existing 1 5/8 cable on the tower but was quite old, they wouldn't even reuse it for 900mhz. Lol
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Hahausuck
Premium
join:2003-12-14
kudos:2
reply to warwick

You probably aren't going to find anyone using it for 5GHz.

It's not good at that frequency as you know. Keep it for use at 900-2.4 and that will be what it is useful for. Or recycle it.



John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:5

1 recommendation

reply to warwick

Maximum upper frequency limit is determined by the distance from the outer surface of the center conductor to the inner surface of the shield. The larger the cable, the lower the frequency...etc.

In all likelihood, you could use it at the upper frequency limits since Andrews is conservative in the ratings (they're selling to engineers who have accurate measurement equipment at their disposal, after all).

The question is why was it pulled from service (if it was). A sweep would be a good idea since cable, unlike fine wine, does not get better with age.
--
No amount of force can control a free man, a man whose mind is free. You can't conquer a free man; the most you can do is kill him. Well, you can try to...



warwick

join:2009-06-05
Hollywood, FL

Thanks for the replies.

It was actually de-commissioned from the neighboring telco as they finally took down all of their legacy antennas/cabling.

Unfortunately I don't have the equipment to sweep the cable.

We learn something new everyday. I presume this upper limit has much to do with the actual length of wavelength itself?

I see very little benefit in using the cable at this point as poe' seems to be the more economical solution.



John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:5

said by warwick:

I presume this upper limit has much to do with the actual length of wavelength itself?

Correct.

If you still want to use heliax in the future for the 5.8 GHz, the 5/8" foam LDF4.5-50 looks like it would work good for you. The attenuation is 4.765 dB/100 ft. per the Andrews spec sheet. The list price is ~$6 per foot...trade pricing less.
--
No amount of force can control a free man, a man whose mind is free. You can't conquer a free man; the most you can do is kill him. Well, you can try to...


wirelessdog

join:2008-07-15
Queen Anne, MD
kudos:1
reply to warwick

Any reputable cable company will have the equipment to sweep the cable.