Denton,
I misread your original post (below).
You were simply asking what people use, rather than what they believe is the
best balun to use.
In that case, there are no wrong answers! (except for my own)
To the question "which balun 'should' one use with a 238 tuner", then there
were good and bad answers.
My suggestion to anyone interested in this topic, especially if you still
believe a 4:1 balun is the best solution, is to read the excellent paper
written on this subject by Tom Rauch, W8JI, entitled "Choosing the correct
balun".
Link:
http://static.dxengineering.com/pdf/Choosing%20the%20Correct%20Balun.pdf
Tom concludes on page 4: "Based on the above, a 4:1 balun or any
voltage-type balun is the wrong choice for use with antenna
tuners in multi-band dipole systems. Most tuners use them because they are
cheap, easy to build, and because almost everyone else uses them."
In addition, Steve, G3TXQ has written an excellent explanation on tuner
balun ratios, HERE:
http://www.karinya.net/g3txq/tuner_balun/
There are other excellent references concluding this same point, including a
book on OCFD antennas written by DL1VU, but they are not in English.
My bottom line on all of this is:
-> The Voltage Balun of any ratio is never right
-> The 4:1 current Balun is sometimes right ( roughly for impedances from
50 to 600 Ohms) , but sometimes a disastrous choice (low impedances),
especially when running high power. For low power, usually most anything
works.
-> The 1:1 current Balun is always a right answer, providing the matchbox
can efficiently match the impedance of the antenna without help.
If you want to know the very best balun for your own situation, then the
question is not what balun for your tuner but rather which balun should you
use for the specific antenna(s) in question. The description has to include
type of antenna, type of feedline, bands to be covered and where the balun
is to be located (e.g. feedpoint, shack, somewhere in between).
In light of all of this, the best answer I read was from Bob, K4TAX.
Unfortunately the prize for the best answer is a Cuban cigar. Since it is
illegal to ship those to the states, I'll just have to smoke it for you,
Bob.
73
Rick, DJ0IP
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of denton
sprague
Sent: Saturday, July 27, 2013 5:00 PM
To: Discussion of Ten-Tec Equipment
Subject: [TenTec] which balun?
Thought would start a little poll..
Which balun are you using with your 238 series TT tuners and multi band
antenna?
Currently, I use a balun designs 4214t 4:1 balun to feed my 80 meter
horizontal loop.with 450 ohm feeders.
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|