I am looking for a vendor for a low pass filter for around 20kHz - ideally it would be variable between around 10 and 100 kHz. The maximum voltage would be around 2V and it doesn't have to have any special attenuation properties - just provide some "reasonable" degree of high frequency suppression.
I was thinking of making one myself using a series inductor in a shielded box, or a capacitative version, but the cost of the Pomona box is $150 which seems kind of ridiculous
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Pomona2390.asp). Compared with other simple components (e.g. a feed- thru terminator) I imagined the low pass filter might cost about $20 but can't find ANY vendors except for top-end, high power filters.