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1994-11-13
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Date: Sun, 29 May 94 04:30:17 PDT
From: Ham-Ant Mailing List and Newsgroup <ham-ant@ucsd.edu>
Errors-To: Ham-Ant-Errors@UCSD.Edu
Reply-To: Ham-Ant@UCSD.Edu
Precedence: Bulk
Subject: Ham-Ant Digest V94 #162
To: Ham-Ant
Ham-Ant Digest Sun, 29 May 94 Volume 94 : Issue 162
Today's Topics:
Apartment rain gutters on 40M
More on 10 meter dipole (3 msgs)
Send Replies or notes for publication to: <Ham-Ant@UCSD.Edu>
Send subscription requests to: <Ham-Ant-REQUEST@UCSD.Edu>
Problems you can't solve otherwise to brian@ucsd.edu.
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: 28 May 1994 04:57:29 GMT
From: ihnp4.ucsd.edu!swrinde!gatech!howland.reston.ans.net!noc.near.net!news.delphi.com!domonkos@network.ucsd.edu
Subject: Apartment rain gutters on 40M
To: ham-ant@ucsd.edu
>My apartment building has a no antenna policy, but they have this beautiful
>system of aluminum rain gutters going up and down the building. (two
story)
>so it's kind of like a long wire that goes up and down the building,
directly
>connected to the building. Anybody tried using the rain gutter on their
>apartment? Does it work? How will the SWR be? I have an MFJ 945 C tuner
>and a Radio Shack nearby for parts to make this work. What
>should I feed it with? Right now, I have coax feeding it, which
>I can receive with but haven't tried to transmit yet.
It'll work w/tuner but unless yu can strap the gutter joints w/jumpers man
you'll have some bad RFI problems (rectification at the gutter joints).
If you have access to an attic (even if only a crawlspace) a slinky dipole
will work great. I use one in my attic w/EXCELLENT results. You need two of
the large metal slinkies, coax, clothesline, 4 alligator clips,and about 4 ft
of wire. Stretch the clothesline end to end w/slinkies in the attic. Stretch
the slinkies about 12 ft each from the center. Add 2 ft of wire to the
far ends of each slinky and attach the coax using alligator clips to the
center of the slinky dipole. Trim (or lengthen) the wire ends of the antenna
for lowest SWR and get ready for some great results!
-----/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ \/\/\/\/\/\/\/\/\/\/\\/\/\/\/\/\/-------
wire slinky coax> ||
||
||
||
||
||
Yes, the above makes an excellent shortwave dipole also.
Good luck and 73...
Andy N3LCW
------------------------------
Date: 27 May 94 18:30:14 -0800
From: ihnp4.ucsd.edu!usc!nic-nac.CSU.net!vax.sonoma.edu!harrisok@network.ucsd.edu
Subject: More on 10 meter dipole
To: ham-ant@ucsd.edu
> Morse code. Well, "es" comes from the Spanish word for "and".
And I always though "y" meant "and" in Spanish... :)
The Spanish word "es" comes from the verb "ser", or "to be", as in:
De donde es Ud.? -- Where are you from?
(Today's little lesson in Spanish...) <grin>
73,
Ken Harrison
N6MHG
email: harrisok@sonoma.edu
------------------------------
Date: Sat, 28 May 1994 03:02:15 GMT
From: ihnp4.ucsd.edu!agate!msuinfo!netnews.upenn.edu!news.drexel.edu!dunx1.ocs.drexel.edu!DUVM.OCS.DREXEL.EDU!XTL00014@network.ucsd.edu
Subject: More on 10 meter dipole
To: ham-ant@ucsd.edu
HICKS.ALAN@epamail.epa.GOV (ALAN HICKS 617-860-4388) writes:
>Message-ID: <01HCSH0H28UE8ZK58O@mr.rtpnc.epa.gov>
>NNTP-Posting-Host: ucsd.edu
>Originator: daemon@ucsd.edu
> [[Replying to N3RCS 's further inquiries abot the mysteries of 10
> meter dipoles]]
>
> Some RG-8M coiled up about 8-12 inches below the antenna
> feedpoint should work just fine as a choke balun. You can do the
> same with RG-213, but it gets pretty heavy :)}
>
> Your antenna WILL work in an attic, but not as well as it would
> out in the open air... Snow or rain on the roof will affect its
> performance adversely. Being closer to the ground will lower the
> impedance somewhat and tend to make more of your signal head
> skyward. An antenna only 15 feet or so above your head is likely
> to send a fair amount of the RF back into the house, too, so try
> to keep the power low. Still, if you need to be circumspect, an
> attic is better than nothing.
>
> The SWR for the antenna if "perfectly cut" with no balun.....
> Hmmm - somebody with a good modeling program like MININEC could
> probably give you a good guess, but you mostly just need to try
> it. If your transmitter likes low SWR, than by all means, trim
> the antenna until you see 1:1. If you're a theoretical purist,
> trim it for 1.5:1. Anyhing in that range will work just fine.
> Like the sneaker ad says, "Just do it!" That's what one of my
> elmers, WA1QYM, told me when I was fretting too much about my
> first homebrew antenna.
>
> Finally, you bet that I didn't know exactly what "es" means in
> Morse code. Well, "es" comes from the Spanish word for "and".
> The ARRL Operating manual says it means "and" and that's how I
> use it. So "Gd luck es 73 de KD1DJ" would mean
>
> "Good luck and best wishes from the old white-bearded guy with
> the sloppy fist from Massachusetts.....:)}"
Tnx for the info. I'll try it.
I heard es was a carry-over from the old american telegraph and it ment
&.
73 de N3RCS es gd DX.
------------------------------
Date: 28 May 1994 04:57:06 GMT
From: ihnp4.ucsd.edu!swrinde!gatech!howland.reston.ans.net!noc.near.net!news.delphi.com!domonkos@network.ucsd.edu
Subject: More on 10 meter dipole
To: ham-ant@ucsd.edu
What can be done w/an indoor antenna? Rain/snow on roof has little effect on
the performance. I use an AEA Isoloop for 10-30M and have worked DX on all
bands from Germany to Australia to Hawaii on CW and SSB w/539 to 569
reports, not bad for a 40 inch diameter resonant loop.
I use a slinky dipole for 40M stretched 30 ft from end-to-end in the attic
w/excellent results.
I also use a trimmed down CB Firestick vertical for 10M, mostly for the
local rag chews and skip when the band is open. 4 radials make up the ground
plane and results are excellent. From my hilltop local in Maryland I have
worked into Delaware (35mi north) and Virgina (75 mi south) ground wave.
BTW, keep the power down, I rarely use anything over 30 watts on CW and SSB,
well the average power is low so setting the rig on high power won't hurt.
The only negative is precautions on feedline radiation, but this is managed
extremely well w/large ferrite beads or toroids w/a few turns of coax around
each.
Final note, the house is vinyl sided w/no metal flashing near the antennas.
I am quite satisfied w/my results and have rec'd enough compliments on my
signals. Hope this helps those of you facing antenna restrictions...
Andy N3LCW
------------------------------
End of Ham-Ant Digest V94 #162
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