QRZ! Ham Radio 4/QRZ Ham Radio Callsign Database - Volume 4.iso/digests/antenna/940099.txt

Internet Message Format | 1994-11-13 | 10KB

Date: Mon, 11 Apr 94 04:30:30 PDT
From: Ham-Ant Mailing List and Newsgroup <[e-mail]>
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Subject: Ham-Ant Digest V94 #99
To: Ham-Ant


Ham-Ant Digest              Mon, 11 Apr 94       Volume 94 : Issue   99

Today's Topics:
                       Coax Loss on HF (4 msgs)
                             Egg beater?
                          HF in an apartment
                     Push up mast...advice needed
                              Radio WANs

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We trust that readers are intelligent enough to realize that all text
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policies or positions of any party.  Your mileage may vary.  So there.
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Date: Sun, 10 Apr 1994 16:44:22 GMT
From: ihnp4.ucsd.edu!library.ucla.edu!csulb.edu!csus.edu!netcom.com![e-mail]
Subject: Coax Loss on HF
To: [e-mail]

As Murphy's Law would dictate, the best trees and location for my 80/40
meter dipole are at a point on my property quite distant from the ham
shack.  If I were to put the dipoles up at that point, my coax run would
be approximately 350 feet.

Does anybody have any experience with long runs of coax at hf?  With good
quality coax, I can't imagine the loss would be that great.  Theory is
one thing - anybody have any experience?  Would appreciate all comments.

Tnx es 73's, Gerry  WA6E

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Date: 10 Apr 1994 17:42:46 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!news.intercon.com!news1.digex.net!rtp.vnet.net!news.sprintlink.net!indirect.com![e-mail]
Subject: Coax Loss on HF
To: [e-mail]

Gerald J. Brentnall ([e-mail]) wrote:

: As Murphy's Law would dictate, the best trees and location for my 80/40
: meter dipole are at a point on my property quite distant from the ham
: shack.  If I were to put the dipoles up at that point, my coax run would
: be approximately 350 feet.

In addition to the loss, which you can look up in the handbook, you will
have a considerable problem supporting that much weight - I assume you will
be using RG-8 or a derivative.

Why not use ladder line?  We have always had great luck with it on long runs
and you only have to worry about keeping it from twisting in the wind :)

73

Pat

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Date: 10 Apr 1994 20:48:58 GMT
From: ihnp4.ucsd.edu!library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!news.intercon.com!news1.digex.net!rtp.vnet.net!news.sprintlink.net!indirect.com![e-mail]
Subject: Coax Loss on HF
To: [e-mail]

Gerald J. Brentnall ([e-mail]) wrote:

: Does anybody have any experience with long runs of coax at hf?
: Tnx es 73's, Gerry  WA6E

Save your money and your losses, Gerry. 350 ft. of ladder-line costs
about $50. Even with an SWR of 1:1 on 40m, 350 ft of RG-58 will eat
up more than half your power with a 3.5 db loss. Loss in 350 ft of
ladder-line on 40m with an SWR of 1:1 is neglible, around 0.3 db.

Here's a question for you... would you radiate more RF with 350 ft. of
RG-58 feeding a 50 ohm antenna with an SWR of 1:1 or with 350 ft. of
ladder-line feeding a 50 ohm antenna with an SWR of 6:1? The answer is
the RG-58 will have more than 3db loss and the ladder-line, even with
the 6:1 SWR, will have less than 1db loss. Ladder-line is the closest
to something-for-nothing that I know of.

Do what the hams did before coax was economically feasible. Use ladder-
line... and an antenna tuner.

73, Cecil, [e-mail]

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Date: 10 Apr 1994 21:17:36 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!wupost!crcnis1.unl.edu!unlinfo.unl.edu![e-mail]
Subject: Coax Loss on HF
To: [e-mail]

[e-mail] (Patrick Berry) writes:

>Gerald J. Brentnall ([e-mail]) wrote:

>: As Murphy's Law would dictate, the best trees and location for my 80/40
>: meter dipole are at a point on my property quite distant from the ham
>: shack.  If I were to put the dipoles up at that point, my coax run would
>: be approximately 350 feet.

>In addition to the loss, which you can look up in the handbook, you will
>have a considerable problem supporting that much weight - I assume you will
>be using RG-8 or a derivative.

>Why not use ladder line?  We have always had great luck with it on long runs
>and you only have to worry about keeping it from twisting in the wind :)

Well, ladder line is one good idea. However, if you want to run coax,
do it. You will find it an advantage to have the antennas that far
from the house. You won't get into the tv/vcr/phone/intercom/etc.
nearly as much as you will with the antenna closer to the house. As
for the weight, you only have to support the vertical portion. The
horizontal run can lay on the ground, tie to a fence, go underground,
whatever. Use copperweld for the antenna, and it will hold up almost
anything. Use at least 9913 quality cable for the long run, and
consider either 1/2" or 7/8" line, if you can afford it. The 1/2" line
is more than good enough. There are some people who run 7/8" though.

73, Gary

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Date: Sun, 10 Apr 1994 22:48:37 GMT
From: netcomsv!netcom.com![e-mail]
Subject: Egg beater?
To: [e-mail]

I used an eggbeater on 2m mobile during a VHF contest shortly after the
antenna became available. Perhaps the best QSO I have with it was a
roundtable that included stations in the San Jose and Drakes Bay areas
of California. I was mobile on I5 just 75 miles or so north of Sacramento
at the time. I was able to contibnue conversing with the two stations as
I drove down I505, I80 and I680 until I arrive home in Milpitas CA.

I was quite impressed by the antenna.

73 de Glenn [e-mail]

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Date: Mon, 11 Apr 1994 01:57:41 GMT
From: netcomsv!netcom.com![e-mail]
Subject: HF in an apartment
To: [e-mail]



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Date: 9 Apr 94 20:22:53 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!news.intercon.com!news1.digex.net!rtp.vnet.net!news.sprintlink.net!connected.com!beauty!rwing!eskimo![e-mail]
Subject: Push up mast...advice needed
To: [e-mail]

In article <[e-mail]>,  <[e-mail]> wrote:
>I have very limited yard space for a tower, so
>for the time being I'm going to use a Radio
>Shack push-up mast mounted on the ground.  It
>is the 19 foot model, and the only antenna that
>will be on it is a 5/8 wave 2 meter ground
>plane.
>
>Can anyone advise me about setting this thing
>up?  RS has a reasonably good installation kit,
>but it doesn't come with stakes for the support
>wires.  Any suggestions about suitable stakes
>for a small mast like this?
>
>Also, how far from the base should I stake out
>support wires?  I have looked through several
>books on the subject, but can't seem to get a
>definitive answer.  I've seen angles on wires
>from about 30 degrees to more that 60.
>
>73's and thanks, KD4CSW
>[e-mail]


Suggestion for stakes:  get a piece of rebar (reinforcing bar used in
concrete) and cut it into suitable lengths.  It will rust, eventually,
but you'll probably take the antenna down and put up something else
long before that becomes a problem :->

45 degrees is a good figure for guy wire angles.  If you have guys
fastened at the 15 foot level for example, just put the stakes 15 feet
out from the base.  The problem comes when you try to put the stakes too
close to the base.  The upward pull becomes greater than the sideways
pull and tends to pull out the stake.  Stakes can resist a sideways pull
far better than a vertical one.

Oh, yes.  The easy way to cut rebar is to use what's known as a
"cut-off" wheel on a circular saw.  It doesn't really cut so much as it
grinds its way through.  The ridges on rebar will help greatly to resist
pulling out.


73 es gl

Bill, W7LZP



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Date: Sun, 10 Apr 1994 10:53:28 GMT
From: ihnp4.ucsd.edu!library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!pipex!uknet!nsa.bt.co.uk![e-mail]
Subject: Radio WANs
To: [e-mail]

Hello all,

 I am very interested in finding out about the state of the market
 for Radio Wans. This is both for potential applications I'm interested
 in and also for general interest.
 I am based in a the Highlands of Scotland which has it's own comms
 problems due to the terrain and dispersion of population amongst
 other things. I can see radio comms as having uses in our area.
 I would be interested in any info people can give in this area eg
 how advanced the market is, who are the main players (plus contacts
 if possible), costs, performance, future plans, even if there's a
 more relevant newsgroup I should be addressing.

 Thanks in advance for your time


  Andrew Muir

Highlands & Islands Enterprise, Inverness, Scotland  [e-mail]

------------------------------

Date: Mon, 11 Apr 1994 00:37:10 GMT
From: rit!isc-newsserver!ultb![e-mail]
To: [e-mail]

References <[e-mail]>, <[e-mail]>, <[e-mail]>
Subject : Re: Egg beater?

In article <[e-mail]> [e-mail] (Glenn Thomas) writes:
>I used an eggbeater on 2m mobile during a VHF contest shortly after the
>(etc.)
>I was quite impressed by the antenna.
>
>73 de Glenn [e-mail]

What's an "eggbeater" antenna?

73...Jim  N2VNO

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End of Ham-Ant Digest V94 #99
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