QRZ! Ham Radio 4/QRZ Ham Radio Callsign Database - Volume 4.iso/digests/antenna/940031.txt

Internet Message Format | 1994-11-13 | 9KB

Date: Sun, 13 Feb 94 04:30:13 PST
From: Ham-Ant Mailing List and Newsgroup <[e-mail]>
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Subject: Ham-Ant Digest V94 #31
To: Ham-Ant


Ham-Ant Digest              Sun, 13 Feb 94       Volume 94 : Issue   31

Today's Topics:
                         Antenna for trade...
                        Coax, Baluns & Dipoles
                Copper Dual-Band Super J-Pole Antenna
                         J-Pole Design Needed
              Need Recommendation for Vertical (2 msgs)

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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: 8 Feb 1994 20:02:19 GMT
From: pa.dec.com!src.dec.com!src.dec.com![e-mail]
Subject: Antenna for trade...
To: [e-mail]

Posting for my brther who doesn't have an account.

****************************************************************************

I have a Cushcraft R7 vertical antena I want to trade for a good
solid state transceiver ( cash make up with antenna if necesary  if
it is a great deal )

I can be rechead by ham radio KD6VTZ or at [phone] if I'm
no there just leave a phone number and I'll return your call asap.

Luis Estrella

*****************************************************************************
Or you can E-Mail me and I'll give him your message.


John Estrella.

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Date: Fri, 11 Feb 1994 06:21:07 GMT
From: netcomsv!netcom.com![e-mail]
Subject: Coax, Baluns & Dipoles
To: [e-mail]

In article <[e-mail]> [e-mail] (Dexter Wm. Francis) writes:
>I'd like to build a simple vertical with two pieces of 3/4" copper or
>aluminum pipe - "center" fed with coax. Do I need a balun or would it
>be just as good to do a an "unfolded" J pole?  1/4 wave matching section,
>co-linear with a 3/4 wave section?  (Is this not a vertical Zepp?)
>
What you could do when you feed the dipole with the coax is to make an
RF choke by making a coil in the coax feedline about 3 inches in diameter
(not critical) with
a few turns.  Keeps RF current off the outside of the coax outer conductor.
Or use some clip on ferrite beads (the sort used for RFI suppression) on
the coax.

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Date: Fri, 11 Feb 1994 20:35:08 GMT
From: agate!apple.com!gallant.apple.com!kielbasa.apple.com![e-mail]
Subject: Copper Dual-Band Super J-Pole Antenna
To: [e-mail]

In article <[e-mail]>, [e-mail] (Yvan Dupont) wrote:

> Did someone build that antenna from KA0NAN that was on the April issue
> of "73 Amateur Radio Today"? What are your experience with it? Ease of
> construction and performance???

Yes, I built one and it seems to work just fine (at least on 2m and
440, I don't have 220). The antenna is a 'cactus j-pole' triband for
2m/220/440 built from copper water pipe and fittings. SWR tune up was
easy; I used plain stainless steel band clamps to hold the coax
connections in place. SWR is 1.5:1 or better on 2m, 1.2:1 or better
on 440.

Additions: I put caps on the bare ends of the matching stubs and the
top of the antenna. These also allow fine-tuning of the element lengths
to be done very easily, and keep water and bugs out to boot.

Hardest part was soldering all the pieces (copper is such a good
conductor of heat) -- a propane torch is mandatory. Lots of joints
are in close proximity, so heating one heated them all... I made
a bunch of wood blocks that were used as spacers, and along with
some clamps kept all the pieces in alignment during soldering.

Total construction time was a couple of hours or so.


Don North   ----   Apple Computer, Inc.   ----   Advanced Technology Group
...!apple!north     [e-mail]      NORTH      KD6JTT     etc,etc,etc
{ Facts are facts,  but any opinions expressed are my own,  and *do not* }
{ represent any viewpoint, official or otherwise, of Apple Computer, Inc }

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

Date: 8 Feb 1994 15:27:48 GMT
From: foxhound.dsto.gov.au!fang.dsto.gov.au!yoyo.aarnet.edu.au!news.adelaide.edu.au!basser.cs.su.oz.au!news.cs.su.oz.au!metro!dmssyd.syd.dms.CSIRO.AU!dmsperth.per.dms.@@munnari.oz.au
Subject: J-Pole Design Needed
To: [e-mail]

In article <[e-mail]>, Rick Aldom  writes:
|>
|> Has anyone tried this type of J pole as a dual band antenna.  I have a
|> "copper cactus" and it works well on both 2mtr and 70 cm......

Actually, I am looking for the design for this very antenna. Anyone that could
forward it to me directly (or post it)? Sure would be appreciated.

|> I am
|> looking for a good dual band antenna for my suzuki sidekick.  The problem
|> is the lack of a good ground plane.  Another design point is I would like
|> it to fit through the garage door.  I can mount it fairly low towards the
|> bumper if required.

I don't know if you are looking for a commercial or homebrew only. If you are
considering commercial, Sinclair (or Sinclabs) has a nice selection of which
some do not require much ground plane (some require none).

No connection to that company... I just have some of their products.

Wayne VE3WQS
[e-mail]

#include<std.company.disclaimer>

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

Date: Fri, 11 Feb 1994 20:56:08 GMT
From: elroy.jpl.nasa.gov!swrinde!cs.utexas.edu!howland.reston.ans.net!sol.ctr.columbia.edu!spool.mu.edu!torn!nott!cunews!freenet.carleton.ca!FreeNet.Carleton.CA![e-mail]
Subject: Need Recommendation for Vertical
To: [e-mail]

Hi all,

I will be moving from an apartment to a house this spring and am looking
forward to getting back on HF.  The home I will be buying has a very small
lot so most wire antennas won't fit.  I would like to try an all band (80
to 10) commercial vertical but don't know which one.  The antenna will be
either roof mounted or mounted on a short tower.  It seems like there are
several makes: Butternut, GAP, Telrex, Hi-gain, etc.  Could anyone with
experience with these or other makes please e-mail me with their comments,
pro or con.

Thanks in advance, 73, Rick VE3QV

--
Rick Bushnell    VE3QV    Ottawa,  Ontario,  Canada
[e-mail]

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Date: 12 Feb 94 19:18:21 GMT
From: agate!news.Brown.EDU!noc.near.net!news.delphi.com!BIX.com![e-mail]
Subject: Need Recommendation for Vertical
To: [e-mail]

[e-mail] (Rick Bushnell) writes:



>Hi all,

>I will be moving from an apartment to a house this spring and am looking
>forward to getting back on HF.  The home I will be buying has a very small
>lot so most wire antennas won't fit.  I would like to try an all band (80
>to 10) commercial vertical but don't know which one.  The antenna will be
>either roof mounted or mounted on a short tower.  It seems like there are
>several makes: Butternut, GAP, Telrex, Hi-gain, etc.  Could anyone with
>experience with these or other makes please e-mail me with their comments,
>pro or con.

>Thanks in advance, 73, Rick VE3QV

>--
>Rick Bushnell    VE3QV    Ottawa,  Ontario,  Canada
>[e-mail]
I've been thinking about a vertical also and been collecting opinions
everywhere I could.  And while I cannot speak from experience (I haven't
yet bought anything), the consensis seems to be that the Cushcraft R5 and
R7 antennas work very, very well (have not heard one single negative
comment, nor was the QST review less than very positive).  Don't know
so much about the others, though I have noticed several posts (just in
the last few days) that the GAP antenna does not work so well.  YMMV.

Regards,
Doug Hamilton    [e-mail]   Ph 508-358-5715
Hamilton Laboratories, 13 Old Farm Road, Wayland, MA  01778-3117

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End of Ham-Ant Digest V94 #31
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