QRZ! Ham Radio 3/QRZ Ham Radio Callsign Database - Volume 3.iso/digests/ham_ant/930117.txt

Internet Message Format | 1994-06-04 | 9KB

Date: Sun, 21 Nov 93 04:30:09 PST
From: Ham-Ant Mailing List and Newsgroup <[e-mail]>
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Subject: Ham-Ant Digest V93 #117
To: Ham-Ant


Ham-Ant Digest              Sun, 21 Nov 93       Volume 93 : Issue  117

Today's Topics:
                        Archery Advice for An
                        ARRL Handbook - HELP!
                    Copper j-pole antenna - where?
                           Helical antenna
                        MFJ Counterpoise ? ? ?
                       Mini-Products Mini-Quad
                          Tower Guy Anchors
                             What is it?

Send Replies or notes for publication to: <[e-mail]>
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Problems you can't solve otherwise to [e-mail].

Archives of past issues of the Ham-Ant Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives/ham-ant".

We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party.  Your mileage may vary.  So there.
----------------------------------------------------------------------

Date: 20 Nov 93 17:22:24 GMT
From: ogicse!emory!europa.eng.gtefsd.com!library.ucla.edu!agate!iat.holonet.net![e-mail]
Subject: Archery Advice for An
To: [e-mail]

if you are any good at fishing, a regular fishing pole with a reel and
as sinker on the line works nicely also. plus, you have the option of
reeling up the line when your finished. b. wb5kxw

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Date: Wed, 17 Nov 1993 13:20:25 -0600
From: munnari.oz.au!spool.mu.edu!sol.ctr.columbia.edu!caen!hellgate.utah.edu!cc.usu.edu!sy_j.pgh.wec.com![e-mail]
Subject: ARRL Handbook - HELP!
To: [e-mail]

In article <2cdevo$[e-mail]>, [e-mail] (Mike Stansberry)
wrote:
>
> Since you're in Colorado Springs, try Centennial Electronics on E. Bijou,
> just across the street From Montgomery Wards.
>
> Mike, K0TER

anybody knows a store in the Pittsburgh, PA area ?

--
"Beware of bugs in the above code; I have only proved it correct, not
tried it."
                -- Donald Knuth

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Date: 16 Nov 1993 16:06:52 GMT
From: usc!math.ohio-state.edu!darwin.sura.net!news-feed-2.peachnet.edu!concert!samba.oit.unc.edu![e-mail]
Subject: Copper j-pole antenna - where?
To: [e-mail]

Anyone out there know what issue of 73 had the constructionarticle on a
copper j-pole antenna? Thanks.
Carty KA2Y [e-mail]


--
   The opinions expressed are not necessarily those of the University of
     North Carolina at Chapel Hill, the Campus Office for Information
        Technology, or the Experimental Bulletin Board Service.
           internet:  laUNChpad.unc.edu or 152.2.22.80

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

Date: 17 Nov 1993 18:45:01 GMT
From: newsstand.cit.cornell.edu!newsstand.cit.cornell.edu![e-mail]
Subject: Helical antenna
To: [e-mail]

In article <[e-mail]> Tony Mantler,
[e-mail] writes:
>hello all,
>        I'm planning on building a helical antenna, but I need the
>formulas for the measurements. Also some tips on construction methods
>would help.
>
>Thanx

The handbook has some information, but the antenna book has more
and the satellite experimenters handbook has some other stuff.
I read both of the latter and everything else I could lay my
hands on, then made up a spreadsheet to allow me to diddle
the values (mostly to get round, reasonable dimensions on
things like diameter, spacing, etc) and observe the effects on
gain and beamwidth. I ended up building a 14 turn RHCP helix
that has been doing yeoman duty for 3-4 years now on oscar
13 for me.

I used the squashed turn radial match method on mine instead
of the 1/4 matching section. Much easier to build and tune and
it's flat from 420-450 mhz (and doesn't do too bad on ch14 either).
I'd really recommend doing that for the matching.

i built mine on two rails of 1x2, with a framework of more
1x2's at the rear to hold a hardware screen reflector.  It's a bit
heavy but it was easy to construct, cheap, and rugged. The dimensions
on mine ended up with a 10 foot boom, 9 inch diameter, 7 inch (I think)
turn spacing and 14 turns.  Gain was calulated at about 16dbi, and it
performs about equal to a KLM 40 cx except you can't switch polarity
and it is about 6db heavier and 8 db cheaper.  It provides good uplink
at 25 watts to AO13.  It's also fun on terrestrial communications
although you throw away 3db to linear antennas. I use it a fair bit
with ATV and it works well there.

If you want a copy of my spreadsheet, email me and we'll see if
we can figure out a way to exchange it.

73 de Kevin, WB2EMS

[e-mail]

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

Date: Fri, 19 Nov 1993 23:54:29 GMT
From: netcomsv!netcom.com![e-mail]
Subject: MFJ Counterpoise ? ? ?
To: [e-mail]

In article <[e-mail]> [e-mail] (John H. Taylor - K3ZKA) writes:
>I operate HF from the second floor of my home with a pair of dipoles
>co-fed.  Although grounding is poor (non-existent), I am not aware of any
>problems with RF in the shack.  Nevertheless, I am interested in improving
>the RF grounding situation.
>
>I have seen advertisements for the MFJ counterpoise which is dsigned for
>situations such as this.  Has anybody had operating experience with the MFJ
>counterpoise and what do they think of it?

I used it in a similar situation, but more RF-hostile. It really
worked well!

Greg

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Date: Thu, 18 Nov 1993 07:48:37 GMT
From: nntp.ucsb.edu!library.ucla.edu!agate!howland.reston.ans.net!cs.utexas.edu!utnut!nott!cunews!freenet.carleton.ca!Freenet.carleton.ca![e-mail]
Subject: Mini-Products Mini-Quad
To: [e-mail]

I'm looking for some help here, does anyone have a manual, or information
showing design/construction for this little 6, 10, 15, 20 mtr beam.
It is a quagi hybrid with capacitive whiskers and band coils.

Please E-Mail to [e-mail]

--
Bill VE3NJW      Advanced Amateur
Packet Address : VE3NJW@VE3KYT.#EON.ON.CAN
Freenet Address: [e-mail]

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Date: 17 Nov 1993 17:00:38 CST
From: ftpbox!mothost!schbbs!maccvm.corp.mot.com![e-mail]
Subject: Tower Guy Anchors
To: [e-mail]

The reason for tensioning to 10% of rated load is to be sure that the
guy on the downwind side of the tower is always in tension. This is
related to a mechanical phenomenon not usually explained in statics
class- You can't push a rope! Applied to this situation, a loose guy
provides absolutely no support to the structure. Warm temperatures will
cause the guys to slacken because the guys are longer than the tower is
tall, both have (almost) the same temperature coefficient of expansion.
This is one more case where tight is better than loose.
------------------------- Original Article -------------------------
Newsgroups: rec.radio.amateur.antenna
From: [e-mail] (Jay Kesterson K0GU)
Subject: Re: Tower Guy Anchors
Date: Tue, 16 Nov 1993 16:19:45 GMT
Reply-To: [e-mail]
References: <[e-mail]> <1993Nov5.061202.27862@ke4zv.
Nntp-Posting-Host: corona.fc.hp.com

Gary Coffman ([e-mail]) wrote:
: If you can get access to a cable tension gauge, set the guy tension to
: 50-75 pounds depending on temperature, the tower will "grow" in warm
: weather so use the higher tension setting then. The guys will loosen in
: cold weather as the tower shrinks.
: Gary

The Rohn catalog says to tension the guys to 10 percent of their rated
value (when using the proper size guys they recommend for various towers).
I'm no expert on why, but thats what is says.

73, Jay K0GU                     [e-mail]

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

Date: 17 Nov 1993 17:08:48 CST
From: ftpbox!mothost!schbbs!maccvm.corp.mot.com![e-mail]
Subject: What is it?
To: [e-mail]

This one sounds like any of a large number of CB base station antennas
which were resonant in the 27 MHz range. Claimed gain ranged from 3 to
11 dB, while actual performance is about 2.1 dBi at best, due to poor
dielectric and sloppy mechanical construction.
------------------------- Original Article -------------------------
From: [e-mail]
Newsgroups: rec.radio.amateur.antenna
Subject: What is it?
Date: 16 Nov 93 16:42:28 CST

I bought an antenna at a garage sale and am not sure what it was designed for.
it is a vertical about 19 feet high with three 8 ft counterpoises at the
bottom.  It has 3 small wires at the top, each about 10in long.  What frequency
was it designed to operate at?

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End of Ham-Ant Digest V93 #117
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