Vtg. GENERAL RADIO type 1231-P2 Tuned Circuit for Type 1231-B or 1232-A Amp

Description

For sale is a piece of electronic equipment that was left behind in the electronics equipment inventory of my late father, stored in a dry smoke and pet-free home.   Dad was an active and avid HAM radio operator for over 70 years, and this item was left in his HAM "shack."   We have learned that it is an accessory to the General Radio Amplifier and Null Detector, which we do not have here.   We may have sold it several years ago, not being aware to look for the accessory, or Dad sold the unit and couldn't find this item.   Anyway, we don't have it.   I hope this is an item that you are looking for to complete
your
vintage "HAM shack"!
My husband helped me out with a bit of research on this item.   Here's some of what he found:
Description:  This is a vintage
General Radio
device,
Type 1231-P2
, which has parallel-tuned circuits used as interstage filters to suppress harmonics, noise and hum during the measurement of individual frequencies.  This device can select circuits, tuned to 400 Herz or one kiloHerz, which are used as fixed frequency filters.  The selection is made by the use of a two-position tumbler switch on the front panel of the device.  (This device is an accessory, used with
General Radio
's
Type 1231-B
Amplifier and Null Detector.  The telephone plug from the
Type 1231-P2
is plugged into the filter jack on the front panel of the Amplifier and Null Detector.  Some technicians also use the
Type 1231-P2
with the external filter jack of the
General Radio
Type 1232A
Tuned Amplifier and Null Detector.)  At the normal voltage levels, the
Type 1231-P2
has a tuning accuracy of +/- 2%, and an attenuation of at least 25 decibels to the second harmonic.
Manufacturer:
General Radio Company
, Cambridge, Massachusetts.
Year of Manufacture:  About 1961
Type Number:  1231-P2
Tuned Circuits:  400 cycles and 1 kilocycle selected by tumbler switch
Tuning Accuracy:  +/- 2% at normal voltage levels
Attenuation:  At least 25 decibels to the second harmonic
Finish:  Black crackle
Mounting:  Four flange-mounted holes in the base (less than 3/16-inch diameter).  Rectangular hole pattern, with hole centers, separated about 2-7/8" and about 3-1/2".  (Mounting hardware is not included.)
Nominal Dimensions:  About 4-1/8" high.  About 3-9/16" wide, and about 4" deep (but allow an additional 1/4" for tumbler switch clearance.)
Weight:  About 3-7/8 pounds
I hope that this is the exact item that you have been looking for!!   Thanks for looking here!!
(radio shelves)