BLIND-HAMS Archives

For blind ham radio operators

BLIND-HAMS@LISTSERV.ICORS.ORG

Options: Use Forum View

Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Colin McDonald <[log in to unmask]>
Reply To:
For blind ham radio operators <[log in to unmask]>
Date:
Fri, 24 Aug 2007 10:17:22 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (76 lines)
You can feed a dipole with nearly anything, as long as you match the feed
line with the feed point impedance to 72 or 75 ohms, or what ever the feed
point impedance is going to be...on a horrizontal dipole it is usually
around 72 ohms in a perfect world.
Then you have to match the impedance again at the radio...though twin
lead/latter line is low loss, if you aren't going a long distance, I am of
the opinion that all this impedance matching and use of baluns just to run
twin lead is redundant and not necesary.
Use low loss 50 ohm coax, and tune the dipole for a low SWR...that is the
best way to operate a dipole.
Use a 1 to 1, or 2 to 1 balun at the feed point to prevent RF from coming
back down the coax.  If you are running the dipole at less then a half wave
on the frequency it is cut for, then use a 2 to 1 balun because the feed
point impedance will be higher and it will be more difficult to tune the
antenna to a low swr.
Otherwise, a 1 to 1 balun is an effective way of eleviating RFI and problems
along the coax or feed line.

I have always had a problem with the idea of using your feed line as part of
the radiating antenna as is the case when using twin lead or latter line.
I would rather get all the power i can right up to the feed point of the
antenna, and let the antenna do the rest of the work from there.
73
Colin, V A6 BKX
----- Original Message ----- 
From: "Frederick" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, August 24, 2007 9:29 AM
Subject: Re: using a dipole


> Hi
>      How does it work to feed a pair of ham sticks with twin lead? What
type
> of omes are we looking at for twin lead on this type of dipole? would I
need
> to buy a ballon?
>
> God bless,
> Mark
> God loves you!
> My ham radio lists.
> http://lists.topica.com/lists/funhamradio.
> http://groups.google.com/group/funhamradio-list
> My personal website
> http://funhamradio.bloki.com
> ----- Original Message ----- 
> From: "Gary Lee" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, August 24, 2007 8:19 AM
> Subject: using a dipole
>
>
> > For jerry:
> >
> > The fact that you have a dipole shouldn't limit you to a single band.  =
> > Feed it with balanced line as far as possible, and use a decent tuner.
=
> > YOu should be able to use it on multiple bands.  I have a homebrew =
> > loaded dipole (approximately 180 feet electrical length) fed with 300 =
> > ohm window line, and I use it on all bands from 160 through 10 meters.
> > Just remember Lou Mccoy's maxim, get as much wire in the air as =
> > possible.
> > Good luck.
> >
> >
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.484 / Virus Database: 269.12.4/969 - Release Date: 8/23/2007
4:04 PM
>
>

ATOM RSS1 RSS2