I'm no RF engineer, but I have over 40 years experience in ham radio and VHF
sales/service, and I suspect that your instrument is lying to you. The true
measure would be to put a wattmeter in the line at the radio, take a
reading, then move the wattmeter to the far end and read again. I think you
will be surprised and pleased. Don't trust the absolute reading of most
wattmeters either. The relative reading showing the difference will tell the
tale.
At HF frequencies, I don't think that there is anything measurable to gain
from fiddling with cable matching. I use a home brew method of connecting
hardline and I find no measurable difference from the manufacturers'
connectors that hit the pocketbook so hard.
Regarding the tower accident a few days ago, I understand that it either a
Canadian rigging company, or Canadian riggers, or both. Does anyone have any
more details?
73
Bill - VE5FN
>Return-Path: <owner-towertalk@contesting.com>
>From: tgstewart@pepco.com
>X-Lotus-FromDomain: CEC
>To: towertalk@contesting.com
To: <towertalk@contesting.com>
>Date: Thu, 30 Oct 1997 09:03:55 -0500
>Subject: Re: [TowerTalk] CATV Hardline
>Sender: owner-towertalk@contesting.com
>X-List-Info: http://www.contesting.com/towertalkfaq.html
>X-Sponsor: W4AN, KM3T, N5KO & AD1C
>
>
>
>---------------------- Forwarded by Tyler G Stewart/BENN/CEC on 10/30/97
>09:00 AM ---------------------------
>
>
>Tyler G Stewart
>10/30/97 09:03 AM
>
>To: n4zr@contesting.com
>cc:
>Subject: Re: [TowerTalk] CATV Hardline (Document link not converted)
>
>Remeasure it using a wattmeter and 75:50 ohm matching transformers and let
>me know what you get.
>
>I wouldnt trust loss measurements from one of those antenna sweepers, and
>most are not set up for 75 ohms. However, it's
>always possible that you have some other problem with that particular
>feedline.
>
>73, Ty K3MM
>
>
>
>
>To: towertalk@contesting.com
>cc: (bcc: Tyler G Stewart/BENN/CEC)
>Subject: Re: [TowerTalk] CATV Hardline
>
>
>
>
>At 12:48 AM 10/24/97 +0100, Tyler Stewart wrote:
>>I've never heard that and have seen no evidence to support it. It's all
>>good stuff and all is a copper clad aluminum center with an aluminum
>jacket.
>>At HF there is almost no difference in loss...it's probably slightly
>higher
>>due to the smaller center conductor of 75 ohm cable. It's not worth
>>worrying about.
>>
>
>For whatever it's worth, my run of approximately 250 feet of 3/4" CATV
>hardline measures (with an Autek RF-1) to have 1.6 dB of loss at 28 MHz -
>not nearly so good as the Handbook table says it should be (about .36
>dB/100 fit). Of course, this includes 2 home-brew UHF connectors. I've
>checked for moisture infiltration, etc., but this is about what the
>installation measured right off the reel. I wonder if others have
>compared measurements of their actual installation with the Handbook table
>-- I'd sure like to recoup that elusive "'nother dB."
>73, Pete Smith N4ZR
>n4zr@contesting.com
>"That's WEST Virginia. Thanks and 73"
>--
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