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)?
[mailto:email@example.com]On Behalf Of Pete Smith
Sent: Thursday, July 18, 2002 11:01 AM
Cc: 'Troy Thoele'; TOWERTALK@contesting.com
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
Check out the World HF
Contest Station Database at
Self Supporting Towers, Wireless Weather Stations, see web site:
Call 888-333-9041 to place your order, mention you saw this ad and take an
additional 5 percent off
any weather station price.
Towertalk mailing list