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[Towertalk] Newbie Question

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Subject: [Towertalk] Newbie Question
From: (Troy Flowers)
Date: Thu, 18 Jul 2002 11:16:59 -0700
Ok I'm a relative newbie so I'll ask also.  I ran 1/2" Heliax up my tower
for HF.  But 75 ohm CATV line can be used also?  Being a cheapskate I'd much
rather spend nothing so explain.  My radio/amp wants 50 ohm but the feed
line is 75 ohm and the antenna is some range also based upon freq.  Are you
supposed to do a complex analysis of this or is it safe to take a simplistic
view of it (in terms of station performance)?
 Troy also.

-----Original Message-----
[]On Behalf Of Pete Smith
Sent: Thursday, July 18, 2002 11:01 AM
To: Red
Cc: 'Troy Thoele';
Subject: Re: [Towertalk] Newbie Question

At 12:44 PM 7/18/02 -0500, Red wrote:
>Normally I'd agree that heliax is overkill on HF, but suggest you check
>the attenuation of any coax, expecially on 10 and 15 meter.  Ordinary RG-8
>loses about 1.2-1.3 dB per 100 feet at 30 MHz.  That amounts to 3 - 3.25
>dB for 350 feet; half the power!

But 75-ohm 3/4" CATV hardline is just a hair lossier than 7/8" Heliax at 30
MHz (.3-.35 dB/100 ft), can often be bought for free, and lends itself to
inexpensive connector fabrication.

73, Pete N4ZR

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