Krohn-Hite 3202(R) and 3200(R) Filter

[jackinnj]

Schematic posted here:
http://www.tech-diy.com/TestEquipmen.../KH3202A_2.gif

More forthcoming

[jackinnj]

OK, got them fixed up very nicely -- what a pleasure to deal with -- the printed circuit boards rotate for easy access"

DIY Test Equipment for Audio and Ham Radio Enthusiasts

These filters regularly go for $20 to $40.

[Conrad Hoffman]

Wow, the price came down. I remember paying more, and I had to beg the dealer to get that price. I don't use it often, but just needed to filter out a bunch of noise in an accelerometer signal the other day. Worked like a champ. Also, noise measurements are meaningless unless the bandwidth is controlled and specified- perfect application for them.

Conrad

[TroelsM]

Hi jackinnj.

I have an old 3202 in an unknown condition.

Do you have experience with these units? - what the best way to start examine such a unit?

I was thinking vario-trafo and slowly ramp up to 110 or 23o depending on the internal setting.

Anything in perticular to watch out for? with a filter like this

Kind Regards TroelsM

[iko]

Got myself a 3103R and can't find a schematic for it. The LP filter seems not steep enough.

[jackinnj]

Originally Posted by TroelsM

Do you have experience with these units? - what the best way to start examine such a unit?

There's not much to go wrong in these units -- I suppose that the filter caps could be replaced if necessary. Only necessary if there's excessive ripple on the power rails. I believe that there's a big electrolytic on the output -- you could replace this with an Elna Silk -- but I wouldn't bother unless there's an issue with leakage.

I use the filters to check crossovers, not for everyday listening! A variac is always a good idea in bringing up old equipment.