[Hallicrafters] R-42 speaker design

[Roy Morgan]

At 11:38 AM 6/26/2006, ARDUJENSKI at aol.com wrote:
>I was amazed at the great sound the old Hallicrafters R-42 produces and
>based upon technology a few generations back. Is the circuit diagram 
>available
>online somewhere?


ftp://bama.sbc.edu/downloads/hallicra/r42/
Schematic for R-42 "Reproducer."

It appears to be two 0.5 uF capacitors and a switch.

>Is it specific to that particular speaker (speaker coil)?  I
>would assume it is some basic L-C circuit for limiting the frequency  range.

It likely is "specific' to the impedance level the thing works at, namely 
500/600 ohms, and would not work at voice coil impedances.  The nature of 
the reproducer matters but not a lot.

It is approximate and NOT the sort of thing used in modern high fi speaker 
crossovers. I seem to remember it is a single cap and a switch.  You must 
assume that any original cap is kaput by now, or at least somewhat leaky. 
That may not matter at all.

Roy



- Roy Morgan
National Institute of Standards and Technology
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