I have a couple of them that I addad the 4th column to. One of them cooked in a rack full of tubes on Contractor Point for years. I wouldn't part with mine. :)
Jeff W6JK --- In [email protected], tony dinkel <[EMAIL PROTECTED]> wrote: > > > I am trying to figure out whether I should throw away my old WE 247B KTU touch tone decoder. Anybody want it? > Museum maybe? Put some pull ups on it and it should not be too hard to do a 12 line to hex converter, > in software. You can't beat the old pot cores and precision caps for acquisition time, it ain't exactly false proof. > When I was working late at night, alone up on Santiago I had a habit of turning down the HT-220 > because it was barfing intermod continuously. So the guys would do cat call whistles into the rptr > to get my attention with the chattering relays. Please, this thing has 20 years of service and sacred rodent > excrement included. I can't just throw it away? > > td > wb6mie > > > > > 2a. Re: DTMF Decoder > Posted by: "Ron Wright" [EMAIL PROTECTED] n9eerptr > Date: Wed Mar 26, 2008 4:19 am ((PDT)) > > I have never played with a computer sound card other than the typical plug it in and let the various program drivers interface to it. > > I bet the sound card is a simple ADC and software looks at the wave form using a look up table that compares what is received and reacts. > > DTMF is much more complex, simple in theory, but can be complex. With varying tone levels, distortion, harmonics, etc the wave form changes drastically. Dedicated circuits and ICs do a much better job. > > 73, ron, n9ee/r >
