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John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:6

1 recommendation

reply to warwick

Re: Andrew 1-5/8" Heliax

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.
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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:6

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...