Be aware that there are about 100 variations on "IRIG B", that is, B000 through B257. You should obtain a copy of "IRIG STANDARD 200-04", the 2004 version, which I believe is the most current. It is available on line, if you Google for it.
--- Graham / KE9H == On Tue, May 19, 2015 at 8:11 PM, Neil Schroeder <gign...@gmail.com> wrote: > A bc635 can be had on eBay for almost nothing. It's not a pleasant piece of > gear, but this is one task it can help you with greatly. > > Tools exist to let you analyse the stream extensively, and the Api is > trivial to learn -but not super featured at the high level. > > On Tuesday, May 19, 2015, Tim Shoppa <tsho...@gmail.com> wrote: > > > See for example the Truetime 820 decoder. Discriminators, One-shots, and > > Flip-Flops with pots to tweak the levels. > > > > Tim N3QE > > > > On Tuesday, May 19, 2015, Joseph Gwinn <joegw...@comcast.net > > <javascript:;>> wrote: > > > > > I'm studying up on how IRIG-B decoder circuits work. What are the good > > > approaches, the bad approaches, especially in the presence of noise? > > > (I asked on the NTP group, with little result beyond the C/C++ decoder > > > software written for the audio channel of a 1990s Sun workstation, > > > which it ate alive: 50% cpu load.) > > > > > > Are there decoder ICs available? > > > > > > The closest to a decoder IC I've found is some FPGA code from a partner > > > of Microsemi (nee Symmetricom): > > > > > > ..< > > > > > > http://www.microsemi.com/products/fpga-soc/design-resources/partners/semquest > > > > > > > > > > All marketing and little technical information. I'll have to find out > > > the details. > > > > > > > > > I find very little, though I did find one intriguing idea using a > > > Costas Loop to lock to the 1 KHz carrier, and a posting suggesting > > > squaring the input signal and phase-locking to the 2 KHz result. Most > > > recent articles on IRIG decoders come from Chinese sources, mostly in > > > the AC power industry. > > > > > > Joe Gwinn > > > _______________________________________________ > > > time-nuts mailing list -- time-nuts@febo.com <javascript:;> > > <javascript:;> > > > To unsubscribe, go to > > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > and follow the instructions there. > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com <javascript:;> > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.