[NLRS] Looking for RF transformer

[jcplatt1 at mmm.com]

I need an RF transformer to go from 50 ohms to a 75 ohm load. The
transformer needs to be good to 100 Mhz, handle around 30 watts full duty
cycle, and have low Q (good bandwidth.)


Hi Jason.   Not sure what your needs are, but have you considered a 1/4
matching section ?    The coax matching section would be an electrical 1/4
wavelength at the frequency of interest with an impendence of Sqrt (50 *
75), or 61 ohms (if I remember this right).    The problem will be to find
a 61 ohm coax ..... not sure if there is one made or not.   I do know that
there is 125 ohm coax and you can parallel two identical 1/4 sections to
arrive at 62.5 ohms which is pretty darn close.  1/4 matching sections are
fairly broad depending on what your definition is for good bandwidth.

On the other hand, a 50 to 75 ohm mismatch is only 1.5 to 1 SWR which is
usually tolerable (depending on what your up to), especially if the
transmitter loads into it.   The matching section could end up having more
loss than the loss due to a 1.5 to 1 SWR mismatch.

Just some thoughts for ya.

73, Jon
W0ZQ