On Nov 28, 2007, at 9:37 PM, Glenn Little WB4UIV wrote: > The 1A is an EIA designation. > > See <http://www.personainternet.com/~northscan/dcss.html> > > Google is your friend. Searched for CTCSS Frequency EIA. > > 73 > Glenn > WB4UIV
There's also an EIA/TIA specification for the reverse burst standards. I don't have access to EIA/TIA standards (since you typically have to pay for them) and judging by the various websites that allude to it (marketing material), there's other things in this spec, it would appear. Here's a blurb from a modern Motorola radio's marketing materials I found a while back: "The industry standard EIA/TIA-603 lists two formats for CTCSS Reverse Burst: The format used by Motorola is 120 degree phase shift for 180 milliseconds, while the format used by all other manufacturers as well as by aftermarket tone equipment makers is 180 degree phase shift for 150 milliseconds." They go on to explain that in RSS you can switch to "non-standard" Reverse Burst on this particular radio. Would love to see the full EIA/TIA-603 spec. But these days when standards are purchased instead of public knowledge... oh well. I'm also surprised the Moto marketing people forgot to put the "(TM)" after the words "Reverse Burst". (GRIN) Maybe it was hiding in the fine print of the document and I missed it. I was more interested in having found a reference to a real EIA/TIA specification for the phase shifts and time periods. Then more Googling found LOTS of manufacturer's marketing materials referencing it, but no copies of the spec sneaking around on someone's website. Oh well. -- Nate Duehr, WY0X [EMAIL PROTECTED]