Stromberg Carlson restoration - ASE 6

[Childof60]

I picked up a 1962 Stromberg Carlson console recently with a wonderful amplifier and separate (not working) preamp - an ASE 6. As part of the repair and restoration I noticed one of the scratch filter inductor coils had cracked apart. The coil value is 2H - which seems huge for a audio filter circuit. The schematic also references the value as "2H". I have searched every combination to try to find some other reference to this strange (very small size but very large value) inductor. The part was manufactured by Aladdin (17-207 and 6045 stamped on the case).

Does anyone have any thoughts to what a suitable replacement should be? I simply do not see how a 2H inductor would pass any audio frequency when switched in. Any thoughts or insight is appreciated.

 

[Tom Bavis]

The Sams parts list says 2 mH, but 2 Henries seems more likely - would give a knee frequency of 15 KHz or so with 220K load. In combination with the 680 pF the L-C filter gives a sharp cutoff (12 dB / octave) and less phase shift at lower frequencies.

I have some 600:600 Ohm transformers that have windings with about 2 Henries - could be a possibility.

 

[Childof60]

The Sams parts list says 2 mH, but 2Henries seems more likely - would give a knee frequency of 15 KHz or so with 220K load. In combination with the 680 pF the L-C filter gives a sharp cutoff (12 dB / octave) and less phase shift at lower frequencies.

Tom,
Thanks for doing the calculation and it makes sense. The broken coil is very small - only an inch long and a half inch diameter. I cannot find any replacement remotely close to the same dimension. Do they not make miniature low voltage inductors with a value in the 2 H range any longer? I am stumped - or looking at the wrong source.

 

[Childof60]

Per your thoughts Tom I will try these as a replacement: http://www.mouser.com/ds/2/397/MET-46-25022.pdf . Worth a try.