RadioBanter - View Single Post

March 23rd 04, 12:04 PM

On 22 Mar 2004 22:01:47 -0800, (Tom Bruhns) wrote:

[filter spec snipped]
It should give you enough voltage gain at 18MHz to drive the second
gate at the fifth harmonic, and should attenuate the third at least
50dB if you build it properly, even with low-ish Qu inductors. This
is rather a "hack" circuit, but works. The premise is that it's
easier to get three inductors all the same value than muck about
tuning the inductors. Make the 47pF, 45pF and 40pF caps variable and
you can peak up the response at your desired frequency. Your
simulation should show a reasonably flat bandpass characteristic,
centered at about 18MHz.

Thanks, Tom! You're even more indefatigable than I am, by the look of
it. I shall look into it...

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