My investigation has led to contradictory and incomplete information and so I turn to you all.

I find a standard of time constant of 75usec, 3db point at 2123 Hz and 6 db/octave is often stated on Internet sites with a single pole filter circuit diagram as the example of the filter. The 1974 Radio Amateur's Handbook only give the filter with no specifics on the characteristics.

The 1995 and 2001 Handbooks show filter schematics sporting time constants of 1 msec! This is 13.3 times longer than the 1974 Handbook.

The 2008 handbook doesn't even acknowledge that pre-emphasis and de-emphasis exists much less give any details of it.

So, here are my issues:

1. db ... the "standard" says 6 db/octave. Is this db as in 10*log(P2/P1) or db as in 20*log(V2/V1)?

2. If I simulate, hand calculate or build and measure (I've done all three of these) a single pole RC filter such as the one that is ubiquitously presented, I will not EVER get 6db/octave even if I consider it as dbV and CERTAINLY if I consider it db (power). Physics will not let me. So, either the 6 db/octave is bogus OR we are talking about a multi-pole filter to achieve this.

3. Will the real time constant PLEASE stand up? I see 75 usec and I see 1 millisecond. 75 usec seems to be more believable, but ARRL's Radio Amateur's Handbook is hard to ignore. Why the change from the 1974 Handbook to the 1995 Handbook?