🚀 go-pugleaf

svaldez@sdcc13.ucsd.edu (@ocf.berkeley.edu  ) writes:

>  I'm experimenting with a transmitter for the AM (.5-1.7 MHz)
>commerical broadcast band and would like to design filters to
>prevent high emissions on the fundamental and harmonic frequencies.

>  Can someone recommend filter designs which can handle several
>watts of power? This can't be too hard yet I'm not an EE major so
>I need formulas/design instructions, etc...  Thanks.

Probably the easiest and best is to simply operate the transmitter
into a resistive (dummy) load.  Then you won't have to worry about
emissions on the fundamental or harmonics.  Ham publications like
the Radio Amateur's Handbook can help with harmonic filters; just
scale the frequency and impedance.  To scale impedance:  divide all
capacitors by the impedance ratio, and multiply all inductors and
resistors.  To scale frequency:  divide all inductors and
capacitors by the frequency ratio.

But "transmitter" implies radiating a signal.  So along with the above
comments comes this unsolicited advice:  unless you have a station
license, don't even think about radiating several watts (or more??)
in any band, and especially not in a broadcast band where you are
liable to attract lots of unwanted attention.