GENERAL RADIO 1952 UNIVERSAL FILTER

According to the manual this is a Fourth Order (Four Pole) Chebishev Filters ,that can be set to Low Pass ,Band Pass ,High Pass and Band Reject . Cut off frequencies are adjustable from 4Hz to 60 kHz in four ranges .Find the complete manual here : https://www.ietlabs.com/pdf/Manuals/GR/GR1952%20IM.pdf

 

Ringmodulator Using XR2206. BY OSAMU HOSHUYAMA

 

From the notes on the web site :An amplifier was added so that a guitar or the like can be input. A bias circuit was added so that it becomes just an oscillator when there is no input signal. It also serves as a knob to prevent only the oscillation sound from leaking out when there is no input signal.

I built this on stripboard somewhat modified ,and fitted in old Russian antenna enclosure . 

krohn-hite_3103a

 

krohn-hite_3103a-4_wide-range_10hz-3mhz_band-pass_filter_1981

bruel-kjaer_1613.1_octave_filter_

 

bruel-kjaer_1613.1_octave_filter_