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Compiled by Mike Morris WA6ILQ
The TS-64 can not only send "Reverse Burst" (160ms of 180 degrees phase shifted tone after the keying line is no longer active), but it will also stop decoding virtually instantly (specs say 160ms) on a detected phase change, otherwise known as "Reverse Burst", "Squelch Tail Elimination"... etc., if your encoder at the sending end does it (normally it's rated to stay open for 350ms on loss of tone). Unfortunately, it only has the 180-degree phase shift, because that is really easy to do. It cannot encode or decode a 120-degree phase shift, so that means it is fairly useless with late model Motorola radios (and a few other radio brands that use 120 degree shifts). On the other hand, another nice feature that shows that the designer did a lot of thought is the encode tone output waveform starts and stops at zero crossing thereby preventing any "click" when turning the tone on and off.
If your second-hand TS-64 doesn't seem to follow the standard chart in the area of the 32 standard tones, don't panic. There were an unknown quantity of early units made with the tone table rearranged to allow for a rotary switch to ground one of the six tone select lines to select six specific (customer requested) tones. If you have a perfectly operating second-hand unit except that the tone table is arranged differently you may have one of those specials.
Note: The TS32 was supplied with colored wires that could be plugged onto any pin, therefore it was useless to give hookup instructions based on wire color. The TS64 has consistent wire colors so it's worth presenting this list:
There is no really easy way to eliminate the reverse burst (and why would you want to?). If you absolutely have to, just ground the PTT IN Lead (the orange wire) then switch the encode tone output (the yellow) wire, perhaps with a set of reed relay contacts in series with the audio, or a FET-based audio pinch-off switch.
This page split from the main index page 16-Nov-2011.
This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.