I don't understand the use of the 4:1 balun. On 80M the feed Z of that
antenna is more likely 25 to 50 ohms. The 4:1 balun would present a
impedance to the RG-213 of 6.5 to 12.5 ohms. You would be much better
with a 1:1 balun configuration. Remember one is not matching the feed
line impedance but is matching the antenna impedance.
The ideal use of a 4:1 balun is with a folded dipole antenna which
presents a 200 to 300 ohm impedance. Now the feed line Z is much closer
matched and the 4:1 balun gets the Z to the coax in the 50 to 75 ohm
range. Much more efficient. This of course is a single band antenna.
See https://www.dj0ip.de/balun-stuff/ for good, accurate, and reliable
information on baluns and their usage. Most hams have it wrong as well
as most manufactures of antenna tuners who include a 4:1 balun.
73
Bob, K4TAX
On 10/30/2021 5:07 PM, [email protected] wrote:
Message: 11
Date: Fri, 29 Oct 2021 18:25:44 -0700 (PDT)
From: MIKE ZANE<[email protected]>
To:"[email protected]" <[email protected]>
Subject: [Elecraft] center fed dipole
Message-ID:<[email protected]>
Content-Type: text/plain; charset=UTF-8
I have no problem with a 130 ft dipole fed with 25 feet of 450 ohm ladder
(window) line to a 4:1 4K balun with 15 feet of RG-213 to my MFJ 989C tuner. I
have run from 5w to 1 KW with it....no problems at all. n6zw
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
