R.F. Choke Design
"DaveM" wrote in message
. ..
"JimL" wrote in message
. com...
Greetings- can someone provide data on their home made choke for
connecting across the output of a 1 KW, 3.5 mhz , transmitter working
into 50 ohms. The so called safety choke to prevent the HV plate voltage
from appearing on the antenna in case of failure of a blocking capacitor.
Normally a commercial 2.5 MHY RFC is used. Perhaps something wound on a
ferrite rod. Thanks, Jim.
You might try calculating the inductance of a choke that presents about
500 to 1000 ohms of inductive reactance of the transmitter frequency. Use
wire that can handle about 2 to 3 times the plate current of the final, or
2 to 3 times the HV fuse rating.
The math is left as an exercise for the OP.
--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters
in the address)
"In theory, there isn't any difference between theory and practice. In
practice, there is." - Yogi Berra
Thanks. That calculation is trivial. A more difficult calculation is
determining what effect say, a 25 uhy choke, would have on the pi network
to which it is connected. Evidentally 1 or 2.5 mhy has a negligible
effect, since it never is considered in the literature I have seen.
Perhaps the same is true for the 25 uhy., but I am too lazy to do the
math.Quicker to just try same. Jim.
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