Hi Top band community,
For a comming DXpedition I need to build a specific splitter with the
following functionalities: 75 ohms input with common mode rejection, two 50
ohms outputs. The band pass will never need to be more than 1.8 to 15 Mhz.
If I follow the rough way, I need a first core for the 1:1 common mode
isolation, two cores for the splitter itself (the first for 2:1 input
impedance lowering and the second for the splitting function including a 1:4
impedance transformation) and one core at each output for auto transforming
75 ohms to 50 ohms. That's obviously too much cores.
I have found on the internet an article from John Bryant and Bill Bowers
( http://www.dxing.info/equipment/rolling_your_own_bryant.dx)
where they use only one core for the splitter. Additionally the primary of
the splitter transformer is symmetric and isolated from the secondary so, it
seems that this splitter can at the same time provide common mode isolation.
If to end I adjust the number of turns of the primary to have an impedance
transformation, It seems that I can get all the above functionalities with
only one core.
I know that there are no free meals so, what is wrong in my reasoning?
73, Gilles VE2TZT
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|