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Old April 11th 04, 11:11 PM
Henry Kolesnik
 
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Default Low Pass Filter ??

I just swept a Drake TV-1000-LP and Bud Variable Low-Pass Filter #LF-601
using an HP 8443 and HP141T with a 8552B and 8553B. The Drake goes from 0
dB at 51.3 MHz and drops to -50 dB at 57.1 MHz. While adjusting the Bud it
was kind of neat to watch the impact of each of the 5 varaible capacitors in
real time I got 0 dB at 41.7 MHz and 60 dB attenuation at 54.5 Mhz. I
didn't try to optimize the Bud for channel 2 as yet, that's next. I'm
guessing I'll lose the extra 10 dB attenuation the Bud provides but maybe
I'll get a sharper knee after I optimize it for channel 2 attenutation. My
question is what happens to the attenuated energy that the low pass blocks
as there are no resistors in either? I'm sure I'll see some surprises as
soon as I sweep both with my return loss bridge as soon as I find it.
Tnx
HankWD5JFR