Jerry, You obviously didn't read what I wrote about running: "the ladderline through a single ferrite core wound with pick-off turns to overcome the phase imbalance "uncertainty problem" ! 73, Steve
I would start with a very practical test. Take the cover off and transmit high power through the existing balun for a while. Stop transmitting and feel the balun to see if it is hot. If it is not, yo
There are two causes of feedline radiation/reception -- common mode current and conductor spacing. A common mode choke AT THE FEEDPOINT can essentially kill the radiation due to common mode current u
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 14 Nov 2010 18:22:37 -0600
Or if the feed line isn't perpendicular to the radiator and so gets coupled to the radiator beyond the choke. At HF, few common spacings are wide enough to radiate seriously. Now at 6m and 2m, 1" spa
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 14 Nov 2010 18:24:27 -0600
Yet if the common mode voltage is enough it conceivable could saturate the core. Some but not all. 73, Jerry, K0CQ _______________________________________________ TenTec mailing list TenTec@contestin
That's the function of the additional choke as egg insulator -- to break the feedline into lengths (from a common mode point of view) where very little current can flow. 73, Jim K9YC ________________
Apropos our previous discussion of "choke baluns"... I believe the locution "choke balun" is often used to refer to various forms of chokes - sometimes made of ferrite beads and sometimes made of rou
You have hit on the heart of the reason why I am so opposed to the use of the word "balun" to describe a half dozen different things that are very different from each other, and why I use the words "
Amen ! It drives the non technical Ham like me crazy . John Molenda kb2huk _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailma
If you do the thermal calculations on the cores commonly used in these chokes you'll find it's almost impossible to saturate them - for typical amateur mode duty-cycles they will over-heat and fractu
I would be more interested in actual measurements than theoretical calculations. Don Jones KO7i Arlington, WA If you do the thermal calculations on the cores commonly used in these chokes you'll find
There are some CM choke impedance measurements here: http://www.karinya.net/g3txq/chokes/ Steve G3TXQ _______________________________________________ TenTec mailing list TenTec@contesting.com http://
Holy Cow.... I meandered around that web site and just fell in love with all that TenTec gear on a single desk... MMMmm....... == James- K8JHR == == _______________________________________________ Te
I was wondering about thermal measurements (temperature rise) since everyone here seems to be fretting about power losses and burning up magnetics, wirewond inductive elements and band switches. Don
http://audiosystemsgroup.com/RFI-Ham.pdf contains a LOT of measured data. 73, Jim K9YC _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contestin
Thermal measurements are bit tough, but the very practical test of running power through the device under test and then feeling it for heat will tell you a lot, and requires no instrumentation beyond
Well, I mean by heavy construction the size of the core, of course, and the number of turns would influence the size of the balun. A core picked to satisfy the band coverage and the power and wire si
Good work, Steve, but I'd love to see this data plotted as curves with log R vs log f. Your discussion of the importance of R is also veyr good, I think you ought to reference my prior publication ab
Technically, you don't have a balun in a link coupled tuner. The link is an independent balanced connection to the transmission line already, and thus balanced in and of itself. In fact, it is the id
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 16 Nov 2010 15:07:28 -0600
Overnight I came up with a concept for a single band Link coupled tuner made entirely of small coax like RG-6 or RG-58 that could be so simple and low cost to construct that the user could build one