Service manual

Guide to ASTRO™ Digital Radios
Figure 3.2 A photo illustration of various PC boards found inside of the Motorola Inc. XTS 3000™. The NTN9121A encryption module
is of the new UCM (version R03.xx firmware) generation. Note the lack of a “vocon” (combined vocoder-controller) board, which is only found
in the ASTRO Digital Saber™ and ASTRO Digital Spectra™ products. Much confusion surrounds this issue on various Internet discussion forums.
A common technical blunder which is often perpetuated on various Internet discussion boards is
that the XTS 3000 has a “vocon”. Posts are made where someone is selling or wishing to buy an XTS
3000™ vocon—no such item exists.
There are two different controller-board versions: Type “A” and type “B”. The earlier “A” series
boards have a different flex connector, which often fails during the disassembly/maintenance process,
because of a weak mechanical design.
Another redundant question that gets raised from time-to-time is how large an XTS 3000™
“vocon” is, in terms of memory size. At this point you know there’s no vocon. But all XTS 3000™s have
1M of flash ROM memory on the controller board to store host firmware in. There’s an urban legend
about a 512K XTS 3000™ controller board, however there’s no such reference in the XTS 3000 Detailed
Service Manual (6881083C90-B) to a 512K controller. Additionally, there hasn’t been a 512K XTS 3000™
offered for sale on “Bat Board” or eBay™, in the last seven years.